title:
T-odd Gluon-Top-Quark Effective Couplings at the CERN Large Hadron
  Collider

abstract:
  The T-odd top-quark chromoelectric dipole moment (tCEDM) is probed through
top-quark-pair production via gluon fusion at the CERN Large Hadron Collider
(LHC) by considering the possibility of having polarized protons. The complete
analytic expressions for the tree-level helicity amplitudes of gg-> ttbar is
also presented. For the derived analytic results we determine the 1-sigma
statistical sensitivities to the tCEDM form factor for (i) typical CP-odd
observables composed of lepton and anti-lepton momenta from t and tbar
semileptonic decays for unpolarized protons, and (ii) a CP-odd event asymmetry
for polarized protons by using the so-called Berger-Qiu (BQ) parametrization of
polarized gluon distribution functions. We find that at the CERN LHC, the
CP-odd energy and angular correlations can put a limit of 10^{-18} to 10^{-17}
g_scm on the real and imaginary parts of the tCEDM, while the simple CP-odd
event asymmetry with polarized protons could put a very strong limit of
10^{-20} g_scm on the imaginary part of the tCEDM.


title: Determination of Vtd/Vts within the Standard Model

abstract:
  We propose a new method to extract the value of |Vtd/Vts| from the ratio of
the decay distributions dBr/ds[B->Xd l^+ l^-}] and dBr/ds[B Xs l^+ l^-].


title: Coherent source radius in ppbar collisions

abstract:
  We use a recently derived result to extract from two-pion interferometry data
from $p\bar{p}$ collisions the radius of the coherent component in the source.
We find a coherent source radius of about $2 fm$.


title:
Hadron colliders as the ``neutralino factory'': Search for a slow decay
  of the lightest neutralino at the CERN LHC

abstract:
  Prospects are examined for the detection of a slow decay of the lightest
neutralino (or any other longlived particles) at the CERN LHC and at Very Large
Hadron Collider (VLHC). We first point out that such hadron colliders will
become the ``neutralino factory'' producing 10^6--10^9 neutralinos/yr, if
gluinos and/or squarks actually exist below O(1) TeV. The lightest neutralino
(\neu), usually assumed to be stable, will be unstable if lighter
superparticles such as the gravitino (\gra) or axino (\axi) exist, or R-parity
is not conserved. The decay signal would, however, be missed in usual collider
experiments, particularly when the decay mostly occurs outside the detector. In
order to search for such a slow decay of \neu, we propose a dedicated
experiment where the collision products are dumped by a thick shield, which is
followed by a long decay tunnel. The decay product of \neu can be detected by a
detector located at the end of the tunnel. The slow arrival time and the large
off angle (to the direction of the interaction point) of the decay product will
provide a clear signature of slowly decaying \neu's. One can explore the decay
length (c\tau) in a wide range, i.e., 0.2 m to 1x10^5 km for \mneu=25 GeV and 1
m to 2 km for \mneu=200 GeV at the LHC. This corresponds to the range of the
SUSY breaking scale \rtF=2x10^5 to 2x10^7 GeV in case of the \neu\to\gamma\gra
decay predicted in gauge-mediated SUSY breaking models. At VLHC, one can extend
the explorable range of \mneu up to 1000 GeV, and that of \rtF up to 1x10^8
GeV. In case of the \neu\to\gamma\axi decay, the Peccei- Quinn symmetry
breaking scale F_a can be explored up to 5x10^11 GeV. The mass of the decaying
particle can be determined by using the correlation between the energy and the
arrival time of the decay product.


title: Triplet Higgs Bosons Production in e^-e^- -Collisions

abstract:
  In the framework of models with Higgs triplets, doubly and singly charged
triplet Higgs boson production in the processes $e^-e^-\to\delta
^{--}_{L,R}Z^0$ and $e^-e^-\to\delta ^{-}_{L}W^-_L$ are considered.


title: Hadronic B-Decays

abstract:
  Non-leptonic two-body decays are discussed on the basis of a generalized
factorization approach. It is shown that a satisfactory description of numerous
decay processes can be given using the same two parameters a_1^{eff} and
a_2^{eff}. Although in general process-dependent, these parameters are not
expected to change markedly. In fact, within error limits, there is no evidence
for a process dependence in energetic B-decays. The success of factorization
allows the determination of decay constants from non-leptonic decays. For the
D_s meson one obtains f_{D_s}=(234\pm25) MeV, for the D^*_s meson
f_{D_s^*}=(271\pm33) MeV. The ratio a_2^{eff}/a_1^{eff} is positive in B-decays
and negative in D-decays corresponding to constructive and destructive
interference in B^- and D^+ decays, respectively. Qualitatively, this can be
understood considering the different scales or \alpha_s-values governing the
interaction among the outgoing quarks. The running of \alpha_s is also the
cause of the observed strong increase of the amplitude of lowest isospin when
going to low energy transitions.


title:
Supersymmetric Inflation, Baryogenesis and \nu_{\mu} - \nu_{\tau}
  Oscillations

abstract:
  In a supersymmetric left-right symmetric model, inflation, baryogenesis (via
leptogenesis) and neutrino oscillations can become closely linked. A familiar
ansatz for the neutrino Dirac masses and mixing of the two heaviest families,
together with the MSW resolution of the solar neutrino puzzle, imply that 1 eV
<_\sim m_{\nu _{\tau }<_\sim 9 eV. The predicted range for the mixing angle
\theta _\mu \tau will be partially tested by the Chorus/Nomad experiment. The
CP violating phase \delta _{\mu \tau } is also discussed.


title: Inclusive hard processes in photon induced reactions

abstract:
  In the following some aspects of inclusive hard processes in photon induced
reactions are reviewed. After a discussion on the properties of hard processes,
the phenomenology of jet production and of charmonium production is presented
in the context of the next-to-leading logarithm approximation of QCD.


title:
Supersymmetric interpretation of high--$Q^2$ HERA events and other
  related issues

abstract:
  In the framework of the minimal supersymmetric standard model (MSSM) with
$R-$parity violation, the high--$Q^2$ HERA events can be interpreted as the
$s-$channel production of a single stop of $M_{\tilde{t}_1} \approx 200$ GeV,
whose dominant decay modes are assumed to be the $R-$parity violating $e^+ + d
$ and the $R-$parity conserving $\chi^+ + b$. Assuming only one coupling
$\bar{\lambda_{131}^{'}}$ is nonzero of order $\sim 0.04-0.12$, we find that
(i) the high$-Q^2$ HERA events can be understood as an $s-$channel stop
production with a subsequent decay into $e^+ + (single ~jet)$, and (ii) the
ALEPH 4-jet events can be understood in the scenario suggested by Carena et
al.. We briefly discuss other physics signals of this scenario at other places
such as HERA, LEP200 and Tevatron. The best test for our scenario is to observe
the stop decay into $\chi^+ + b$ followed by $\chi^+ \to \tilde{e}^+ + \nu_e $
and $\tilde{e}^+ \to q + \bar{q}^{'}$ via the $R-$parity violating coupling.


title: Approximations for W-Pair Production at Linear-Collider Energies

abstract:
  We determine the accuracy of various approximations to the O(alpha)
corrections for on-shell W-pair production. While an approximation based on the
universal corrections arising from initial-state radiation, from the running of
alpha, and from corrections proportional to m_t^2 fails in the Linear-Collider
energy range, a high-energy approximation improved by the exact universal
corrections is sufficiently good above about 500GeV. These results indicate
that in Monte Carlo event generators for off-shell W-pair production the
incorporation of the universal corrections is not sufficient and more
corrections should be included.


title: Perturbative Analysis of the MSSM Electroweak Phase Transition

abstract:
  Light stops can give a strong first order electroweak phase transition in the
Minimal Supersymmetric Standard Model (MSSM) satisfying one of the necessary
conditions for electroweak baryogenesis. I discuss the region of parameter
space where this occurs using a perturbative analysis of the Higgs effective
potential. Two-loop QCD corrections associated with stop loops are crucial to
open this baryogenesis window, which corresponds to 2.25 < tan beta < 3.6, one
stop not much heavier than the top quark, m_A > 120 GeV and a light Higgs boson
with m_h < 85 GeV. This region will be explored by LEP II very soon.


title: Progress in perturbative QCD

abstract:
  We briefly summarize some recent theoretical developments in perturbative
QCD, emphasizing new ideas which have led to widening the domain of
applicability of perturbation theory. In particular, it is now possible to
calculate efficiently processes with many partons; the high order behavior of
perturbation theory can be at least partly understood by going beyond leading
twist accuracy; factorization with more than one hard scale (such as in DIS
with heavy quarks) can be made consistent with the renormalization group; and
large infrared logs can be resummed beyond the renormalization group. The use
of the renormalization group to resum large longitudinal scales may allow the
use of perturbation theory even in the absence of a large transverse scale.


title: Inflation in Supersymmetric Unified Theories

abstract:
  We construct supersymmetric unified models which automatically lead to a
period of inflation. The models all involve a U(1) symmetry which does not
belong to the MSSM. We consider three different types of models depending on
whether this extra U(1) is the subgroup of a non abelian gauge group, is a U(1)
factor belonging to the visible sector or is a U(1) factor belonging to the
hidden sector. Depending on the structure of the unified theory, on the
spontaneous symmetry breaking pattern and on whether we have global or local
supersymmetry, inflation may be driven by the non-vanishing vacuum expectation
value of a F-term or by that of a D-term. In both scenarios cosmic strings form
at the end of inflation, and they have different properties in each model. Both
inflation and cosmic strings contribute to the CMBR temperature anisotropies.
We show that the strings contribute to the $C_l$'s up to the level of 75 %.
Hence the contribution from strings to the CMBR and to the density
perturbations in the early Universe which lead to structure formation cannot be
neglected. We also discuss a very interesting class of models which involve a
$U(1)_{B-L}$ gauge symmetry.


title: Two-Loop N=4 Supersymmetric Amplitudes and QCD

abstract:
  Two-loop four-gluon N=4 susy amplitudes are evaluated via cutting techniques
as a testing ground for QCD. A conjecture for four-point amplitudes to all loop
orders is described. We also present a new conjecture for the leading-color
part of the two-loop five-gluon amplitudes.


title: e+ e- Cross Section and Exclusion of Massless Electroweak Gauginos

abstract:
  Measurements of the total hadronic cross section in e+e- annihilation are
shown to be capable of severely limiting the possibility that gauginos have
negligible tree level masses. A combined analysis of 1997 and earlier LEP data,
considering simultaneously conventional SUSY signatures and purely hadronic
final states, should achieve a 95% cl sensitivity to the case that the SU(2)
and U(1) gauginos are massless. If integrated luminosity targets are achieved,
it should also be possible to exclude the case that the wino or wino and gluino
are light while the bino is heavy, except possibly for a small region of mu,
tan beta. The analysis applies whether or not R-parity is conserved, and can
also be used to reduce the model-dependence of conventional SUSY searches.


title: Isgur-Wise Function for $\Lambda_b \to \Lambda_c$ in B-S Approach

abstract:
  In the heavy quark limit, the heavy baryon $\Lambda_Q$ (Q=b or c) can be
regarded as composed of a heavy quark and a scalar light diquark which has good
spin and flavor quantum numbers. Based on this picture we establish the
Bethe-Salpeter (B-S) equation for $\Lambda_Q$ in the leading order of $1/m_Q$
expansion. With the kernel containing both the scalar confinement and
one-gluon-exchange terms we solve the B-S equation numerically. The Isgur-Wise
function for $\Lambda_b \to \Lambda_c$ is obtained numerically from our model.
Comparison with other model calculations are also presented. It seems that the
Isgur-Wise function for $\Lambda_b \to \Lambda_c$ drops faster than that for $B
\to D$. The differential and total decay widths for $\Lambda_b \to \Lambda_c l
\bar{\nu}$ are given in the limit $m_{b,c}\to \infty$.


title: Possible effects of quark and gluon condensates in quarkonium spectra

abstract:
  The Cornell potential with the best fitted parameters $\alpha_{s}$ and
$\kappa$ are modified by adding terms derived from non-perturbative QCD, which
are characterized by a series of non-vanishing vacuum condensates of quarks and
gluons. In terms of this potential, we study the system of heavy quarkonia. The
results show that the correction caused by the additional terms reduces the
deviation between the data and the values calculated with the pure Cornell
potential and improves the splittings of energy levels. The achievements
indicate that the non-perturbative effects induced by vacuum condensates play
an important role for the correction to $1/q^2$, which in general was
phenomenologically put in by hand. This result would be helpful for
understanding non-perturbative QCD along a parallel direction to the QCD sum
rules.


title: Two-loop gluon diagrams from string theory

abstract:
  We briefly review the string technology needed to calculate Yang-Mills
amplitudes at two loops, and we apply it to the evaluation of two-loop vacuum
diagrams.


title: The Bloch-Nordsieck propagator at finite temperature

abstract:
  We have shown recently that the resummation of soft photon contributions
leads to a non-exponential decay of the fermion excitations in hot QED plasmas.
The retarded propagator of a massless fermion was found to behave as $S_R(t >>
1/gT) \sim \exp{-\alpha T t [\ln(\omega_p t) + C]}$, where $\omega_p=gT/3$ is
the plasma frequency, $\alpha=g^2/4\pi$, and $C$ is a constant, independent of
$g$, which was left undefined. This term is computed in this paper. In gauges
with unphysical degrees of freedom, it is gauge-fixing independent provided an
infrared regulator is introduced in the gauge sector. We also extend our
analysis to hot QCD and express the quark and gluon propagators in the form of
three-dimensional Euclidean functional integrals which may be evaluated on the
lattice.


title: R parity violating contribution to $e^+e^-(\mu^+\mu^-)\to t{\bar c}$

abstract:
  In this article we consider the contribution of $R_p$ violating couplings to
the process $e^+e^-(\mu^+\mu^-)\to t{\bar c}$ at high energy lepton collider.
We show that the present upper bound on the relevant $R_p$ violating coulpings
obtained from low energy measurements would produce a few hundred to a thousand
top-charm events at the next linear $e^+e^-(\mu^+\mu^-)$ collider. Hence, it
should be possible to observe the rare process at future lepton collider.


title: Instanton Phenomenology at HERA

abstract:
  This talk describes the physics input of QCDINS, a Monte Carlo event
generator for QCD-instanton induced scattering processes in deep-inelastic
scattering.


title: QCD-Instantons in eP Scattering

abstract:
  We review recent theoretical results from our systematic study of
QCD-instanton contributions to eP processes, involving a hard momentum scale Q.
The main issues are: the absence of IR divergencies due to a dynamical
suppression of instantons with large size rho > 1/Q, the reliable calculability
of instanton-induced amplitudes and our inclusive framework to systematically
calculate properties of the instanton-induced multi-parton final state.


title: Decay Rate and Hyperfine Structure of the bound mu+ mu- system

abstract:
  Results are obtained for the decay rate of ortho and para states and for the
hyperfine structure of the dimuonic system mu+ mu- (dimuonium). We calculate
next--to-leading order radiative corrections. It is shown that previously
reported results for the decay rate of ortho states are incomplete. The decay
rate is strongly influenced by the electronic vacuum polarization in the far
time-like asymptotic region and thus allows for a test of QED in a previously
unexplored kinematic regime.


title: Heavy to light baryon transition form factors

abstract:
  Recently, Stech found form factor relations for heavy to light transitions
based on two simple dynamical assumptions for spectator partical. In this work
we generalize his approach to the case of baryons and find that for
$\Lambda_{Q}\to\Lambda$ ($Q=b$ or $c$) only one independent form factor remains
in limit $m_{Q}\to\infty$. Furthermore, combining with the model of Guo and
Kroll we determine both of the two form factors for $\Lambda_{Q}\to\Lambda$ in
the heavy quark limit. The results are applied to $\Lambda_{b}\to\Lambda +
J/\psi$ which is not clarified both theoretically and experimentally. It is
found that the branching ratio of $\Lambda_{b}\to\Lambda + J/\psi$ is of order
10^{-5}.


title:
The dissipative potential induced by QCD at finite temperature and
  density

abstract:
  In the framework of QCD at finite temperature we have obtained dissipative
terms for the effective potential between $q$ and $\bar q$ which would partly
explain the $J/\psi$ suppression in the Quark Gluon Plasma (QGP). The
derivation of the dissipative potential for QGP is presented and the case for
Hadron Matter (HM) is briefly discussed. The suppression effects are estimated
based on simple approximations.


title:
Applications of the superflavor symmetry to heavy baryon-antibaryon pair
  production in electron-positron collision

abstract:
  The baryons containing two heavy quarks and a light quark are believed to
have the diquark-quark structure and the diquark is composed of the two heavy
quarks which is a spin-0 or spin-1 object. The superflavor symmetry can
associate productions of such heavy baryon-antibaryon pair with the heavy meson
productions. The whole scenario is presented in some details in this work, and
the observation prospect in future experiments is discussed.


title: Polarization of high-energy electrons traversing a laser beam

abstract:
  When polarized electrons traverse a region where the laser light is focused
their polarization varies even if their energy and direction of motion are not
changed. This effect is due to interference of the incoming electron wave and
an electron wave scattered at zero angle. Equations are obtained which
determine the variation of the electron density matrix, and their solutions are
given. The change in the electron polarization depends not only on the Compton
cross section but on the real part of the forward Compton amplitude as well. It
should be taken into account, for example, in simulations of the $e \to \gamma$
conversion for future $\gamma \gamma$ colliders.


title:
Gauge-Boson Pair Production at the LHC: Anomalous Couplings and
  Vector-Boson Scattering

abstract:
  We compare vector boson fusion and quark antiquark annihilation production of
vector boson pairs at the LHC and include the effects of anomalous couplings.
Results are given for confidence intervals for anomalous couplings at the LHC
assuming that measurements will be in agreement with the standard model. We
consider all couplings of the general triple vector boson vertex and their
correlations. In addition we consider a gauge invariant dimension-six extension
of the standard model. Analytical results for the cross sections for quark
antiquark annihilation and vector boson fusion with anomalous couplings are
given.


title: Large Rapidity Gap Events in DIS

abstract:
  Diffractive scattering in DIS is discussed in terms of the perturbative
two-gluon model and numerical results for $F_2^D$ are presented.


title: Minimalism in Inflation Model Building

abstract:
  In this paper we demand that a successfull inflationary scenario should
follow from a model entirely motivated by particle physics considerations. We
show that such a connection is indeed possible within the framework of concrete
supersymmetric Grand Unified Theories where the doublet-triplet splitting
problem is naturally solved. The Fayet-Iliopoulos D-term of a gauge
$U(1)_{\xi}$ symmetry, which plays a crucial role in the solution of the
doublet-triplet splitting problem, simultaneously provides a built-in
inflationary slope protected from dangerous supergravity corrections.


title: Analytic Perturbation Theory and Inclusive Tau Decay

abstract:
  We apply analytic perturbation theory to the inclusive decay of a $\tau$
lepton into hadrons. It is shown that the resulting analyticity of the coupling
constant strongly influences the value of the QCD $\Lambda$-parameter extracted
from the experimental data on $\tau$ decay.


title:
Light-Ray Evolution Equations and Leading-Twist Parton
  Helicity-Dependent Nonforward Distributions

abstract:
  We discuss the calculation of the evolution kernels \Delta W_{\zeta}(X,Z) for
the leading-twist nonforward parton distributions G_\zeta(X,t) sensitive to
parton helicities. We present our results for the kernels governing evolution
of the relevant light-ray operators and describe a simple method allowing to
obtain from them the components of the nonforward kernels \Delta
W_{\zeta}(X,Z).


title: Operator Expansion for Diffractive High-Energy Scattering

abstract:
  I discuss the operator expansion for diffractive high-energy scattering and
present the non-linear evolution equation for the relevant Wilson-line
operators which describes both the propagator of the BFKL pomeron and the
three-pomeron vertex.


title:
Supersymmetric QCD Corrections to Single Top Quark Production at the
  Fermilab Tevatron

abstract:
  We evaluate the supersymmetric QCD corrections to single top quark production
via $q \bar q'\to t \bar b$ at the Fermilab Tevatron in the minimal
supersymmetric model. We find that within the allowed range of squark and
gluino masses the supersymmetric QCD corrections can enhance the cross section
by a few percent. The combined effects of SUSY QCD, SUSY EW, and the Yukawa
couplings can exceed 10% for the smallest allowed $\tan\beta~ (\simeq 0.25)$
but are only a few percent for $\tan\beta >1$.


title: A quark model analysis of the transversity distribution

abstract:
  The feasibility of measuring chiral-odd parton distribution functions in
polarized Drell-Yan and semi-inclusive experiments has renewed theoretical
interest in their study. Models of hadron structure have proven succesful in
describing the gross features of the chiral-even structure functions. Similar
expectations support our study of the transversity parton distributions in the
Isgur-Karl and MIT bag models. We confirm the diverse low x behavior of the
transversity and spin structure functions at the experimental scale and show
that it is fundamentally a consequence of the different behavior under
evolution of these functions. The inequalities of Soffer establish constraints
between data and model calculations of the chiral-odd transversity function.
The approximate compatibility of our model calculations with these constraints
conferes credibility to our estimates.


title: The Bethe-Heitler Process in Polarized Photon-Nucleon Interactions

abstract:
  We calculate the Bethe-Heitler cross section for the production of lepton
pairs in the field of a longitudinally polarized nucleon, taking into account
the lepton masses and the target mass. This process is a dominant background to
the detection of open charm from semi-leptonic decay modes, which is a
potential probe of the polarized gluon distribution in the nucleon.


title: Catalysis of proton decay in superstring theory

abstract:
  Theory of superstrings on Calabi-Yau manifolds is applied to investigate
catalysis of proton decay.


title: Leading Baryons at Low x_L in DIS and Photoproduction at ZEUS

abstract:
  Results obtained by the ZEUS collaboration on leading baryon production in
the proton fragmentation region are presented. The reaction $\gamma p \to N X$,
with N a proton or a neutron, is examined both at low and high photon
virtuality.


title: Heavy quark expansion and universal form factors in quark model

abstract:
  Meson transition amplitudes of the vector, axial-vector, and tensor quark
currents are analyzed within dispersion formulation of the constituent quark
model. The form factors in the decay region are given by relativistic double
spectral representations through the wave functions of the inital and final
mesons. We perform heavy quark expansion of the quark-model mesonic matrix
elements with a next-to-leading order accuracy and demonstrate that matching
this expansion to the heavy-quark expansion in QCD requires subtractions in the
double spectral representations for the form factors and allows fixing the
subtraction terms. The Isgur-Wise function and next-to-leading order universal
form factors are calculated.


title:
Effective Analysis of the O(N) Antiferromagnet: Low Temperature
  Expansion of the Order Parameter

abstract:
  We investigate the low energy properties of Lorentz-invariant theories with a
spontaneously broken rotation symmetry O(N) $\to$ O(N--1). The leading
coefficients of the low temperature expansion for the partition function are
calculated up to and including three loops. Emphasis is put into the special
case N=3: it describes the antiferromagnet which has been extensively studied.
Our results obtained within the framework of the effective Lagrangian technique
are compared with the literature. In particular, we show that, at order $T^7$
for the heat capacity and $T^6$ for the order parameter, respectively,
logarithmic terms appear in the low temperature expansion, which have been
overlooked so far.


title: Examination of Wandzura-Wilczek Relation for $g_2(x,Q^2)$ in pQCD

abstract:
  In order to examine the validity of Wandzura-Wilczek relation for the
polarized DIS structure function $g_2(x,Q^2)$, we use the light-front
time-ordering pQCD to calculate $g_2(x,Q^2)$ at order $\alpha_s$ on a quark
target. We find that the study of the transverse polarized structure function
in pQCD is only meaningful if we begin with massive quarks. The result shows
that the Wandzura-Wilczek relation for $g_2(x,Q^2)$ is strongly violated by the
quark mass in pQCD.


title: Two-loop anomalous dimensions for the structure function h1

abstract:
  Chiral-odd structure function h1 is expected to be measured in polarized
Drell-Yan process. We calculate two-loop anomalous dimensions for h1 in the
minimal subtraction scheme. Dimensional regularization and Feynman gauge are
used for calculating the two-loop contributions. Our results are important in
studying Q^2 dependence of h1.


title: Couplings of heavy hadrons with soft pions from QCD sum rules

abstract:
  We estimate the couplings in the Heavy Hadron Chiral Theory (HHCT) lagrangian
from the QCD sum rules in an external axial field. We take into account the
perturbative correction to the meson correlator in the infinite mass limit.
With the perturbative correction and three successive power corrections, the
meson correlator in an axial field becomes one of the best known correlators.
In spite of this, the corresponding sum rule is not very stable. It yields the
result g_1 F^2/(380MeV)^3 = 0.1 - 0.2, where F^2 = f_M^2 m/4 = (380MeV)^3 is
the central value of the heavy meson decay constant with the perturbative
correction. This result is surprisingly low as compared with the constituent
quark model estimate g_1 = 0.75. The sum rules for g_{2,3} following from
nondiagonal Sigma-Sigma and diagonal Lambda-Sigma baryon correlators in an
external axial field suggest g_{2,3} = 0.4 - 0.7, while diagonal Sigma-Sigma
and nondiagonal Lambda-Sigma baryon sum rules have too large uncertainties.


title: O(N_f\alpha^2) Corrections to Muon Decay

abstract:
  The calculation of the $O(N_f\alpha^2)$ corrections to muon decay is
described. These are the 2-loop diagrams containing a massless fermion loop and
they form an important gauge-invariant subclass. It is shown that all such
diagrams can be expressed in terms of a universal master integral. We focus on
the calculation of box diagrams and in particular on the removal of their
infrared divergences.


title: Structure of Vacuum Condensates

abstract:
  It is essential to know the space-time structure of the nonlocal vacuum
condensates for application to medium energy processes. Using the
Dyson-Schwinger formalism in the rainbow approximation for the quark
propagator, we study the nonlocal quark condensate and model forms for the
nonperturbative gluon propagator constrained by fits to local condensates and
deep inelastic scattering with nucleon targets.


title:
Numerical Approaches to High Energy Electroweak Baryon Number Violation
  Above and Below the Sphaleron Barrier

abstract:
  We review some promising numerical techniques for calculating high energy
baryon number violating cross sections in the standard model. As these lectures
are designed to be self- contained, we present in some detail the formalism of
Rubakov, Son, and Tinyakov, which provides a means of bounding the two-particle
cross sections in a semi-classical manner. The saddle-point solutions required
by this method must be found computationally and are of two basic types,
corresponding to tunneling events between adjacent topological sectors on the
one hand, and classically allowed evolution over the sphaleron barrier on the
other. In both cases one looks for topology changing solutions of small
incident particle number. In the classically allowed regime we have developed a
Monte Carlo technique that systematically lowers the particle number while
still ensuring that a change in topology takes place. We also make progress
towards a numerical method amenable for the more computationally challenging
problem of finding the complexified tunneling solutions, and we present some of
our numerical findings, both above and below the sphaleron barrier.


title:
A QCD space-time analysis of quarkonium formation and evolution in
  hadronic collisions

abstract:
  The production of heavy quarkonium as QQbar bound-states in hadron-hadron
collisions is considered within the framework of a space-time description,
combining parton-cascade evolution with a coalescence model for bound-state
formation. The `hard' production of the initial QQbar, directly or via gluon
fragmentation and including both color-singlet and color-octet contributions,
is calculated from the PQCD cross-sections. The subsequent development of the
QQbar system is described within a space-time generalization of the DGLAP
parton-evolution formalism in position- and momentum-space. The actual
formation of the bound-states is accomplished through overlap of the QQbar pair
and a spectrum of quarkonium wave-functions. This coalescence can only occur
after sufficent gluon radiation reduces the QQbar relative velocity to a value
commensurate with the non-relativistic kinematics of these bound systems. The
presence of gluon participants in the cascade then is both necessary and leads
to the natural inclusion of both color-singlet and color-octet mechanisms. The
application of this approach to pp (ppbar) collisions from sqrt(s)= 30 GeV - 14
TeV reveals very decent agreement with available data from ISR and Tevatron -
without the necessity of introducing fit parameters. Moreover, production
probabilities are calculated for a complete spectrum of charmonium and
bottonium states, with the relative significance compared to open charm
(bottom) production. An analysis of the space-time development is carried
through which sheds light on the relevance of gluon radiation and
color-structure, suggesting a correponding experimental investigation.


title:
Intermediate baseline appearance experiments and three-neutrino mixing
  schemes

abstract:
  Three-neutrino mixing schemes suggested by Cardall & Fuller and Acker &
Pakvasa are compared and contrasted. Both of these schemes seek to solve the
solar and atmospheric neutrino problems and to account for the possible
neutrino oscillation signal in the LSND experiment. These neutrino oscillation
schemes have different atmospheric and solar neutrino signatures that will be
discriminated by Super-Kamiokande and SNO. They will also have different
signatures in proposed long-baseline accelerator and reactor experiments. In
particular, both of these schemes would give dramatic (and dramatically
different) signals in an ``intermediate baseline'' experiment, such as the
proposed ICARUS detector in the Jura mountains 17 km from CERN.


title:
Virtual photon scattering at high energies as a probe of the short
  distance pomeron

abstract:
  Perturbative QCD predicts the behavior of scattering at high energies and
fixed (sufficiently large) transferred momenta in terms of the BFKL pomeron (or
short distance pomeron). We study the prospects for testing these predictions
in two-photon processes at LEP200 and a possible future e+ e- collider. We
argue that the total cross section for scattering two photons sufficiently far
off shell provides a clean probe of BFKL dynamics. The photons act as color
dipoles with small transverse size, so that the QCD interactions can be treated
perturbatively. We analyze the properties of the QCD result and the possibility
of testing them experimentally. We give an estimate of the rates expected and
discuss the uncertainties of these results associated with the accuracy of the
present theoretical calculations.


title: A Natural Solution to the Neutrino Mixing Problem

abstract:
  The combined requirements, of (i) a natural solution to the fermion mass
hierarchy problem and (ii) an explanation of both the atmospheric and solar
neutrino problems, lead to an essentially unique picture of neutrino masses and
mixing angles. The electron and muon neutrinos are quasi-degenerate in mass
with maximal mixing, giving $\nu_e - \nu_{\mu}$ vacuum oscillations. The
overall neutrino mass scale is set by the atmospheric neutrino requirement
$\Delta m^2 \sim 10^{-2}$ eV$^2$, implying a mass for $\nu_e$ and $\nu_{\mu}$
of order 1 eV in models with a natural mass hierarchy, whilst the tau neutrino
is expected to be much lighter than this and only weakly mixed. We present an
explicit example based on the anti-grand unification model of fermion masses.


title: Supersymmetry Breaking with Vanishing F-terms in Supergravity Theories

abstract:
  In conventional supergravity theories, supersymmetry is broken by a non-zero
F-term, and the cosmological constant is fine tuned to zero by a constant in
the superpotential W. We discuss a class of supergravity theories with
vanishing F-terms but $W \not= 0$ being generated dynamically. The cosmological
constant is assumed to be cancelled by a non-zero D-term. In this scenario the
gravity-mediated soft masses depend only on a single parameter, the gravitino
mass. They are automatically universal, independently of the Kahler metric, and
real. Thus, dangerous flavor or CP violating interactions are suppressed.
Unlike in conventional supergravity models, the Polonyi problem does not arise.


title:
Strong Coupling Constant with Flavour Thresholds at Four Loops in the
  MS-bar Scheme

abstract:
  We present in analytic form the matching conditions for the strong coupling
constant alpha_s^(n_f)(mu) at the flavour thresholds to three loops in the
modified minimal-subtraction scheme. Taking into account the recently
calculated coefficient beta_3 of the Callan-Symanzik beta function of quantum
chromodynamics, we thus derive a four-loop formula for alpha_s^(n_f)(mu)
together with appropriate relationships between the asymptotic scale parameters
Lambda^(n_f) for different numbers of flavours n_f.


title: Gauge Invariance in Boson Production

abstract:
  It is shown how to construct exactly gauge-invariant S-matrix elements for
processes involving unstable gauge particles such as the $W$ and $Z^0$ bosons.
The results are applied to derive a physically meaningful expression for the
cross-section $\sigma(e^+e^-\to Z^0Z^0)$ and thereby provide a solution to the
long-standing problem of the unstable particle. The problem of maintaining QED
gauge-invariance in the process $e^+e^-\to\bar\nu_e e^-W^+\to\bar\nu_e e^-u\bar
d$ is examined.


title: The Signatures Of Glueballs In $J/\psi$ Radiative Decays

abstract:
  Quantitative signatures of glueballs in $J/\psi$ radiative decays are
discussed. Further experimental and theoretical investigations are sugessted.


title:
Testing new physics/couplings at the NLC (Talk prsented in The 5th
  Topical Seminar on ``The irresistible rise of the Standard Model'', San
  Miniato al Todesco, Italy, April 21-25 1997)

abstract:
  I present a brief overview of the advantages of using a consistent effective
Lagrangian approach in parameterizing virtual new physics effects. I then apply
the formalism to certain top-quark processes.


title: Non-standard t production at the NLC

abstract:
  The top-quark system as a probe for new physics is considered using a
consistent, gauge-invariant effective Lagrangian approach. The magnitude of new
effects is estimated and the results are applied to top production through W
fusion. Other processes are also briefly discussed.


title: Final results from the NMC

abstract:
  A summary of the results on deep inelastic muon nucleon and muon nucleus
scattering experiments performed by the NMC collaboration is presented.


title: High Momentum Transfer HERA Events and pQCD at High x

abstract:
  We compare data on the proton structure function from SLAC experiments in the
range of x between 0.7 and 0.97 in and near the resonance region with previous
empirical fits to Deep Inelastic Scattering and with calculations from parton
distribution functions. The data is in rough agreement with the empirical fits,
but is an order of magnitude higher than the pQCD calculations at the highest
x. This compares with the two orders of magnitude increase in the quark
distributions at high x which seem to be necessary to explain the HERA high
momentum transfer events.


title: Jet Production in DIS at NLO

abstract:
  Dijet production in DIS is an important laboratory for testing our
understanding of perturbative QCD. Flexible NLO Monte Carlo programs allow to
investigate general jet definition schemes. For forward jet production at
$p_{Tj} \approx Q$ and $x_{jet} >> x$ the NLO predictions fall well below HERA
data, thus providing evidence for BFKL dynamics.


title: Super-oblique corrections and non-decoupling of supersymmetry breaking

abstract:
  If supersymmetric partners of the known particles have masses at the
multi-TeV scale, they will not be directly discovered at planned future
colliders and decouple from most observables. However, such superpartners also
induce non-decoupling effects that break the supersymmetric equivalence of
gauge boson couplings $g_i$ and gaugino couplings $h_i$ through supersymmetric
analogues of the oblique corrections. Working within well-motivated theoretical
frameworks, we find that multi-TeV scale supersymmetric particles produce
deviations at the 1-10% level in the ratios $h_i/g_i$. Such effects allow one
to bound the scale of kinematically inaccessible superpartners through
precision measurements of processes involving the accessible superparticles.
Alternatively, if all superpartners are found, significant deviations imply the
existence of highly split exotic supermultiplets.


title:
Conditions for Viable Affleck-Dine Baryogenesis -- Implications for
  String Theories

abstract:
  We examine the conditions for a viable Affleck-Dine baryogenesis in
supergravity (SUGRA) scenarios, finding surprisingly strong constraints on the
type of SUGRA theory. These constraints are beautifully fulfilled by
string-based SUGRA models provided that inflation is driven by a modulus (T)
field.


title: Large Squark-Mixing Impact on H^+ Decay in the MSSM

abstract:
  We study the decays of the charged Higgs boson H^+ within the Minimal
Supersymmetric Standard Model. We find that the supersymetric mode 'stop +
sbottom-bar' can dominate the H^+ decays in a wide range of the model
parameters due to the large Yukawa couplings and mixings of stop and sbottom.
Compared to the conventional modes 'tau^+ nu' and 't b-bar', this mode has very
distinctive signatures. This could have a decisive impact on H^+ searches at
future colliders. We find also that the QCD corrections to the 'stop +
sbottom-bar' mode are significant, but that they do not invalidate our
tree-level conclusion above.


title: Nonfactorizable soft gluons in nonleptonic heavy meson decays

abstract:
  We include nonfactorizable soft gluon corrections into the perturbative QCD
formalism for exclusive nonleptonic heavy meson decays, which combines
factorization theorems and effective field theory. These corrections are
classified according to their color structures, and exponentiated separately to
complete the Sudakov resummation up to next-to-leading logarithms. The
nonfactorizable contributions in nonleptonic decays are clearly identified in
our formalism, and found to be positive for bottom decays and negative for
charm decays. Our analysis confirms that the large-$N_c$ approximaton is
applicable to charm decays, but not to bottom decays, consistent with the
phenomenological implications of experimental data. The comparision of our
predictions with those from QCD sum rules is also made.


title: Compositeness Condition

abstract:
  By solving the compositeness condition, under which the Yukawa-type model
coincides the NJL type model, we obtain the expressions for the effective
coupling constants in terms of the compositeness scale at the next-to-leading
order in 1/N. In the NJL model with a scalar composite, the next to leading
contributions are too large for N_c=3. In the induced gauge theory with abelian
gauge symmetry, the correction term is reasonably suppressed, while in the
non-abelian gauge theory the corrections are suppressed only when it is
asymptotically non-free.


title: J/\psi Electromagnetic Production at e^+e^- colliders

abstract:
  Within the framework of QED we investigate the inclusive J/\psi production at
$e^+e^-$ colliders. It is expected to be as a further test to the charmonium
production mechanisms and QED. We find that at the energies of CESR, BEPC, and
TRISTAN (e.g. 4.0 GeV \leq \sqrt s \leq 60 GeV), the contributions of the
concerned electromagnetic processes to the $J/\psi$ inclusive production are
great, even dominant, thus they greatly affect the observation of the
color-octet $J/\psi$ production signature at $e^+e^-$ colliders. The production
of \psi', being similar to that of J/\psi's, is roughly estimated, and its
influence on the observation of the color-octet J/\psi production signature in
e^+e^- collision is also discussed.


title:
O(alpha_s) Spin-Spin Correlations for Top and Bottom Quark Production in
  e+ e- Annihilation

abstract:
  We present the full O(alpha_s) longitudinal spin-spin correlations for
heavy-quark pair production at e+ e- high-energy colliders in closed analytical
form. In such reactions, quark and antiquark have strongly correlated spins,
and the longitudinal components are dominant. For the explicit computation of
the QCD bremsstrahlung contributions, new phase-space integrals are derived.
Explicit numerical estimates are given for t t_bar and b b_bar production.
Around the Z-peak, QCD one-loop corrections depolarize the spin-spin asymmetry
for bottom quark pairs by approximately -4%. For top pair production, we find
at 350GeV a 0.6% increased polarization over a value of 0.4 in the longitudinal
correlation. For more than 1 TeV the O(alpha_s) corrections enhance
depolarization to -2% in the top-pair case.


title:
Final-state Interaction Effects on Inclusive Two-particle Production in
  Electron-positron Annihilation

abstract:
  The final-state interaction effects on the inclusive two-particle production
in electron-positron annihilation are investigated within the context of the
one-photon annihilation approximation. Such effects are characterized by one
structure function in the decomposition of the hadronic tensor. On the basis of
the positivity, we derived an inequality to bound this structure function. The
price to access it experimentally is to polarize longitudinally one of the
initial-state beam, to say, the electron beam, and measure the corresponding
single spin asymmetry. By combining the Callan-Gross relation with our
positivity analysis, we obtain an upper bound for the single spin asymmetry
considered.


title: Parton Densities from Collider Data

abstract:
  Collider data can play an important role in determining the parton
distribution functions of the nucleon. I outline a formalism which makes it
possible to use next-to-leading order calculations in such an extraction, while
minimizing the amount of numerical computation required.


title: Advanced Techniques for Multiparton Loop Calculations: A Minireview

abstract:
  We present an overview of techniques developed in recent years for the
efficient calculation of one-loop multiparton amplitudes, in particular those
relying on unitarity and collinear factorization.


title: Lessons and puzzles of DIS at low x (high energy)

abstract:
  This talk is a rather sceptical review of our knowledge and understanding of
deep inelastic scattering at low x (high energy). We show that the well known
success of the DGLAP evolution equations in describing of experimental HERA
data brought more problems and puzzles than answers. We advocate that more
systematic theoretical and experimental investigations of the nonperturbative
QCD are needed to clarify physics of DIS at high energy.


title: NRQED and Next-to-Leading Hyperfine Splitting in Positronium

abstract:
  We compute the next-to-leading, O(m alpha^5), contribution to the hyperfine
splitting in positronium within the framework of NRQED. When applied to the
ground state, our calculation reproduces known results, providing a further
test of NRQED techniques. Besides providing a very simple method of calculation
of the standard result, we also obtain new expressions for excited states of
positronium with negligible additional effort. Our calculation requires the
complete next-to-leading matching of the lowest-dimension NRQED four-fermi
couplings, which we publish here for the first time.


title: Relativistic effects in the pionium lifetime

abstract:
  The pionium decay width is evaluated in the framework of chiral perturbation
theory and the relativistic bound state formalism of constraint theory.
Corrections of order O(\alpha) are calculated with respect to the conventional
lowest-order formula, in which the strong interaction amplitude has been
calculated to two-loop order with charged pion masses. Strong interaction
corrections from second-order perturbation theory of the bound state wave
equation are found to be of the order of 0.4%. Electromagnetic radiative
corrections, due to pion-photon interactions, are estimated to be of the order
of -0.1%. Electromagnetic mass shift insertions in internal propagators produce
a correction of the order of 0.3%. The correction due to the passage from the
strong interaction scattering amplitude evaluated with the mass parameter fixed
at the charged pion mass to the amplitude evaluated with the mass parameter
fixed at the neutral pion mass is found to be of the order of 6.4%.


title: Flavor democracy and quark mass matrices

abstract:
  Based on experimental mass hierarchy, a set of flavor-democratic (FD) quark
mass matrices at low energies is discussed. The model predicts CP violation
parameters $J_{CP}=(0.3 \pm 0.2) 10^{-4}$ and ${\epsilon'/\epsilon} = (0.6 \pm
0.5) 10^{-3}$. However, this simple FD model also predicts a physical top quark
mass not much higher than 100 GeV. As a next step, we assume that the Standard
Model (SM) breaks down around some high energy $\Lambda$, and is replaced by a
new FD flavor gauge theory (FGT). This possibility can be investigated by
studying renormalization group equations for the Yukawa couplings of the SM
with two Higgs doublets for various $m_t$ and VEV ratios $v_U/v_D$. With
appropriate flavor-democratic boundary conditions at $\Lambda_{FGT}$, bounds on
masses of top quark and tau-neutrino are derived, which are compatible with
experimental bounds.


title: Interpretations of $J/\psi$ suppression

abstract:
  We review the two main interpretations of $J/\psi$ suppression proposed in
the literature. The phase transition (or deconfining) scenario assumes that
below some critical value of the local energy density (or of some other
geometrical quantity which depends both on the colliding systems and on the
centrality of the collision), there is only nuclear absorption. Above this
critical value the absorptive cross-section is taken to be infinite, i.e. no
$J/\psi$ can survive in this hot region. In the hadronic scenario the $J/\psi$
dissociates due both to nuclear absorption and to its interactions with
co-moving hadrons produced in the collision. No discontinuity exists in
physical observables. We show that an equally good description of the present
data is possible in either scenario.


title: Soft Modes associated with Chiral Transition at Finite Temperature

abstract:
  Using a novel resummation procedure of thermal loops, real-time correlations
in the scalar and pseudo-scalar channels are studied in the O(4) linear sigma
model at finite temperature. A threshold enhancement of the spectral function
in the scalar channel is shown to be a noticeable precritical phenomenon of the
chiral phase transition.


title:
A low-energy compatible SU(4)-type Model for Vector Leptoquarks of Mass
  <= 1 TeV

abstract:
  The Standard Model is extended by a SU(2)L singlet of vector leptoquarks. An
additional SU(4) gauge symmetry between right-handed up quarks and right-handed
leptons is introduced to render the model renormalizable. The arrangement is
made in such a way that no conflict with low energy restrictions is
encountered. The SU(2)L singlet mediates interactions between the right-handed
leptons and up type quarks for which only moderate low energy restrictions
M(LQ)/g(LQ) > few hundred GeV exist. We cancel the anomalies of the model and
furthermore argue that the inequality g(LQ) > g(QCD) is a general feature of
consistent vector leptoquark models. Although our model is not relevant for
HERA, it is interesting per se as a description of leptoquarks of mass < 1 TeV
consistent with all low-energy requirements.


title: A unified BFKL/DGLAP description of Deep Inelastic Scattering

abstract:
  We introduce a coupled pair of evolution equations for the unintegrated gluon
distribution and the sea quark distribution which incorporate both the resummed
leading $\ln (1/x)$ BFKL contributions and the resummed leading $\ln (Q^2)$
DGLAP contributions. We solve these unified equations in the perturbative QCD
domain. With only two physically motivated parameters we obtain an excellent
description of the HERA $F_2$ data.


title:
Gluon Polarization from Correlated High-p_T Hadron Pairs in Polarized l
  - N Scattering

abstract:
  We propose to access the gluon polarization $\Delta G$ by measuring the cross
section spin-asymmetry in semi-inclusive polarized lepton -- nucleon
scattering. The photon-gluon fusion sub-process will be tagged by detecting
high-$p_T$ correlated hadron pairs in the forward hemisphere. Selecting
oppositely charged kaon pairs will allow to suppress the background coming from
gluon radiation.


title: Renormalon Phenomenology: Questions and Directions

abstract:
  A qualitative (and selective) discussion of current activities and problems
in the field is given.


title: Semiclassical Calculation of Diffractive Parton Densities

abstract:
  In this talk the relation between the semiclassical approach and the concept
of diffractive parton densities is discussed. The proton rest frame calculation
is organized in a way that exhibits the hard partonic cross section and the
diffractive parton density as the two fundamental ingredients. The latter one
is a non-perturbative quantity which, in the present model, is explicitly given
by integrals of non-Abelian eikonal factors in the colour background field.


title: Asymptotic Freedom at Small x

abstract:
  We describe how perturbative QCD may be applied to inelastic e-p scattering
at high center-of-mass energies, i.e. at small x and fixed Q^2.


title:
Multiparticle production in high-mass diffraction dissociation and the
  interplay of photons and pomerons

abstract:
  Multiple interaction models satisfying $s$-channel unitarity predict that, in
contrast to inelastic processes, factorization is violated in diffractive
processes. The size of this effect can be characterized in terms of the
rapidity gap survival probability. The possibility of its measurement at HERA
is pointed out. Furthermore a method to measure photon diffraction dissociation
at LEP2 and planned linear colliders is discussed and cross section predictions
are given.


title:
Nucleon described by the chiral soliton in the chiral quark soliton
  model

abstract:
  We give a survey of recent development and applications of the chiral quark
soliton model (also called the Nambu-Jona-Lasinio soliton model) with $N_f$=2
and $N_f$=3 quark flavors for the structure of baryons. The model is an
effective chiral quark model obtained from the instanton liquid model of the
quantum chromodynamics. Mesons appear as quark-antiquark excitations and
baryons arise as non-topological solitons with three valence quarks and a
polarized Dirac sea. In this model, a wide variety of observables of baryons is
considered.


title:
Complete QCD Corrections of Order O(\alpha_s^3) to the Hadronic Higgs
  Decay

abstract:
  We consider the decay of an intermediate mass Higgs boson into hadrons up to
order O(\alpha_s^3). The results from the diagrams containing only light
degrees of freedom were recently computed in a previous work by K.G. Ch. (Phys.
Lett. B 390 (1997) 309). In this letter the remaining contributions involving
the top quark are evaluated analytically using an effective field theory
approach. Coupled with the previous result the present calculation determines
the complete next-next-to-leading order correction to the hadronic decay rate
of an intermediate mass Higgs boson.


title:
CP-violating Parameters for Neutral B-mesons and Their Complete
  Measurement

abstract:
  Phenomenological CP-violating parameters in decays of neutral B-mesons are
discussed with special attention to the degree of their measurability.
Important role of the sign of \Delta m_B is emphasized. We briefly describe how
it could be determined experimentally.


title: New quadratic baryon mass relations

abstract:
  By assuming the existence of (quasi)-linear baryon Regge trajectories, we
derive new quadratic Gell-Mann-Okubo type baryon mass relations. These
relations are used to predict the masses of the charmed baryons absent from the
Baryon Summary Table so far, in good agreement with the predictions of many
other approaches.


title:
The Chirally Normalized Vector Meson Dominance Model and Semihadronic
  Tau Decays

abstract:
  We discuss and test the assumptions of the chirally normalized vector meson
dominance model (CN-VMD), as it is used for tau decays. We compare the CN-VMD
amplitudes with those using on-shell couplings, derived directly from
experimental data. We discuss in detail the $3\pi$, $K K \pi$ and $2\pi$ final
states. We suggest that the true values for the $K_1$ widths might be larger
than those quoted in the Review of Particle Physics.


title: The Btev Program

abstract:
  A brief description is given of BTeV a proposed program at the Fermilab
collider sited at the C0 intersection region. The main goals are measurement of
mixing, CP violation and rare decays in both the $b$ and charm systems. The
detector is a two arm forward-backward spectrometer capable of triggering on
detached vertices and dileptons, and possessing excellent particle
identification, electron, photon and muon detection.


title:
Pade Approximants, Optimal Renormalization Scales, and Momentum Flow in
  Feynman Diagrams

abstract:
  We show that the Pade Approximant (PA) approach for resummation of
perturbative series in QCD provides a systematic method for approximating the
flow of momentum in Feynman diagrams. In the large-$\beta_0$ limit, diagonal
PA's generalize the Brodsky-Lepage-Mackenzie (BLM) scale-setting method to
higher orders in a renormalization scale- and scheme-invariant manner, using
multiple scales that represent Neubert's concept of the distribution of
momentum flow through a virtual gluon. If the distribution is non-negative, the
PA's have only real roots, and approximate the distribution function by a sum
of delta-functions, whose locations and weights are identical to the optimal
choice provided by the Gaussian quadrature method for numerical integration. We
show how the first few coefficients in a perturbative series can set rigorous
bounds on the all-order momentum distribution function, if it is positive. We
illustrate the method with the vacuum polarization function and the Bjorken sum
rule computed in the large-$\beta_0$ limit.


title: Hybrids and Quark Confinement

abstract:
  It has become traditional to assume that the Dirac structure of the
phenomenological quark confinement potential is scalar $\otimes$ scalar. We use
the heavy quark expansion of the Coulomb gauge QCD Hamiltonian and the Flux
Tube model to demonstrate that this is true but in the effective sense only.
The demonstration contains some surprises: confinement is actually vector
$\otimes$ vector and it is nonperturbative mixing between ordinary and hybrid
$Q \bar Q$ states which generates the scalar-like spin dependent potential at
order $1/m_q^2$. Thus the existence of hybrids is crucial to establishing
well-known spin splitting phenomenology. Finally, the resolution also indicates
that the gluonic degrees of freedom in a hybrid must be of a collective nature.


title:
Importance of Tests for the Complete Lorentz Structure of the t --> W+ b
  vertex at Hadron Colliders

abstract:
  The most general Lorentz-invariant decay-density-matrix for $t\to W^{+}b\to
(l^{+}\nu)b$, or for $t\to W^{+}b\to (j_{\bar d}j_u)b$, is expressed in terms
of eight helicity parameters. The parameters are physically defined in terms of
partial-width-intensities for polarized-final-states in $t\to W^{+}b$ decay.
The parameters are the partial width, the $b$ quark's chirality parameter
$\xi$, the $W^+$ polarimetry parameter $\sigma$, a "pre-SSB" test parameter
$\zeta$, and four $W_{L}$-$W_{T}$ interference parameters $\eta$, $\eta^{'}$,
$\omega$, $\omega^{'}$ which test for $\tilde T_{FS}$ violation. They can be
used to test for non-CKM-type CP violation, anomalous $\Gamma_{L,T}$'s, top
weak magnetism, weak electricity, and second-class currents. By stage-two
spin-correlation techniques, percent level statistical uncertainites are
typical for measurements at the Tevatron, and several mill level uncertainites
are typical at the LHC.


title: Structure Function Subgroup Summary

abstract:
  We summarize the studies and discussions of the Structure Function subgroup
of the QCD working group of the Snowmass 1996 Workshop: New Directions for High
Energy Physics.


title: Electroweak Theory Without Higgs Bosons

abstract:
  A perturbative SU(2)_L X U(1)_Y electroweak theory containing W, Z, photon,
ghost, lepton and quark fields, but no Higgs or other fields, gives masses to
W, Z and the non-neutrino fermions by means of an unconventional choice for the
unperturbed Lagrangian and a novel method of renormalisation. The
renormalisation extends to all orders. The masses emerge on renormalisation to
one loop. To one loop the neutrinos are massless, the A -> Z transition drops
out of the theory, the d quark is unstable and S-matrix elements are
independent of the gauge parameter xi.


title:
Beyond the Narrow Resonance Approximation: Decay Constant and Width of
  the First Pion-Excitation State

abstract:
  We consider the first pion excitation as a sub-continuum resonance in the
pseudoscalar channel, and we obtain parameters characterizing this resonance
through a global fit of the Borel-parameter dependence of the field-theoretical
pseudoscalar Laplace sum rule to its hadronic (pion + pion-excitation +
QCD-continuum) content. Our analysis incorporates finite-width deviations from
the narrow resonance approximation, instanton effects, and higher-loop
perturbative contributions to the pseudoscalar correlator. We obtain the
following values (uncertainties reflect 90% confidence levels): mass $M_\Pi =
1.15 \pm 0.28 GeV$, width $\Gamma_\Pi = < 0.48 GeV$, decay constant $r \equiv
[F_\Pi M_\Pi^2 / f_\pi m_\pi^2]^2 = 4.7 \pm 2.8$.


title: QCD Laplace Sum Rules and the $\Pi (1300)$ Resonance

abstract:
  A global fit to the shape of the first QCD Laplace sum rule exhibiting
sensitivity to pion-resonance [$\Pi (1300)$] parameters is performed, leading
to predictions for the pion-resonance mass and decay constant. This fit leads
to predictions of $M_{\pi} = 1.15 \pm 0.15 GeV$ for the pion-resonance mass,
and $F_\pi^2=(4.5\pm 2.1).(f_\pi^2m_\pi^4/M_\pi^4)$ for the pion-resonance
decay constant.


title: Models of Dynamical Supersymmetry Breaking

abstract:
  We review a class of models of dynamical supersymmetry breaking, and give a
unified description of these models.


title: New Mechanisms of Gauge-Mediated Supersymmetry Breaking

abstract:
  We review the motivation for Gauge-Mediated Supersymmetry Breaking and
discuss some recent advances.


title: Signatures of multi-TeV scale particles in supersymmetric theories

abstract:
  Supersymmetric particles at the multi-TeV scale will escape direct detection
at planned future colliders. However, such particles induce non-decoupling
corrections in processes involving the accessible superparticles through
violations of the supersymmetric equivalence between gauge boson and gaugino
couplings. In a previous study, we parametrized these violations in terms of
super-oblique parameters and found significant deviations in well-motivated
models. Here, we systematically classify the possible experimental probes of
such deviations, and present detailed investigations of representative
observables available at a future linear collider. In some scenarios, the
$e^-e^-$ option and adjustable beam energy are exploited to achieve high
precision. It is shown that precision measurements are possible for each of the
three coupling relations, leading to significant bounds on the masses and
properties of heavy superparticles and possible exotic sectors.


title: An Overview of $D^0\bar{D}^0$ Mixing Search Techniques

abstract:
  The search for $D^0\bar{D}^0$ mixing may carry a large discovery potential
for new physics since the $D^0\bar{D}^0$ mixing rate is expected to be small in
the Standard Model. This paper gives a brief review of the experimental
techniques which can be used to search for $D^0\bar{D}^0$ mixing in the future.
Some ideas, applicable to future mixing searches at hadron machines (such as
Tevatron and LHC), and fixed target experiments (such as HEAR-B) are
introduced.


title: Supersymmetric Partners of Oblique Corrections

abstract:
  We discuss a potential new probe of supersymmetric physics. In particular, we
discuss the possibility of measuring hard supersymmetry violation which occurs
at one loop through "super-oblique" corrections to the gauge and gaugino
propagators. In models with heavy scalar partners, or with many gauge-charged
particles which participate in supersymmetry breaking, these effects can be
substantial due to logarithmic and multiplicity factor enhancements.


title: Yukawa Unification in Moduli-dominant SUSY Breaking

abstract:
  We study Yukawa unification in string models with moduli-dominant SUSY
breaking. This type of SUSY breaking in general leads to non-universal soft
masses, i.e., soft scalar masses and gaugino masses. Such non-universality is
important for phenomenological aspects of Yukawa unification, i.e., successful
electroweak breaking, SUSY corrections to the bottom mass and the branching
ratio of $b \to s \gamma$. We show three regions in the whole parameter space
which lead to successful electroweak breaking and allow small SUSY corrections
to the bottom mass. For these three regions we investigate the $b \to s \gamma$
decay and mass spectra.


title:
The Heavy Quark Parton Oxymoron -- A mini-review of Heavy Quark
  Production theory in PQCD

abstract:
  Conventional perturbative QCD calculations on the production of a heavy quark
``$H$'' consist of two contrasting approaches: the usual QCD parton formalism
uses the zero-mass approximation ($m_H=0$) once above threshold, and treats $H$
just like the other light partons; on the other hand, most recent ``NLO'' heavy
quark calculations treat $m_H$ as a % large parameter and always consider $H$
as a heavy particle, never as a parton, irrespective of the energy scale of the
physical process. By their very nature, both these approaches are limited in
their regions of applicability. This dichotomy can be resolved in a unified
general-mass variable-flavor-number scheme, which retains the $m_H$ dependence
at all energies, and which naturally reduces to the two conventional approaches
in their respective region of validity. Recent applications to lepto- and
hadro-production of heavy quarks are briefly summarized.


title: Some Remarks on the Baryon-Meson Couplings in the 1/N_c Expansion

abstract:
  The original results for the baryon-pion couplings in the large $N_c$ QCD can
be understood in a simpler way in the Hartree-Fock picture. The large $N_c$
relation and its $1/N_c$ correction between the heavy baryon-meson coupling and
the light baryon-meson coupling are emphasized. Application to the
baryon-$\rho$ meson interactions is straightforward. The implications of recent
experimental result for the strong coupling constants of the heavy baryon
chiral lagrangian are discussed.


title: Neutrino Mass Constraints on R violation and HERA anomaly

abstract:
  R parity violating trilinear couplings $\lambda'_{1jk}$ of the minimal
supersymmetric standard model (MSSM) are constrained from the limit on the
electron neutrino mass. Strong limits on these couplings follow from the
earlier neglected contribution due to sneutrino vacuum expectation values. The
limits on most of the $\lambda'_{1jk}$ couplings derived here are stronger than
the existing ones for a wide range in parameters of MSSM. These limits strongly
constrain the interpretation of recent HERA results in $e^+ p$ scattering in
terms of production of squarks through $R$ violating couplings. In particular,
the interpretation in terms of $\tilde{t}_L$ production off strange quark as
suggested recently is not viable for wide ranges in MSSM parameters.


title:
Dynamically generated masses in supersymmetric QCD and quark mass
  problems

abstract:
  We consider possible mechanical masses that could appear in supersymmetry,
other than by direct Higgs coupling to fermions and we speculate that the
existence of such a type of mass would allow one to have the Higgs mass of the
$u$ quark zero, and the Higgs mass of the $d$ quark (at 1 \gev) of $\approx 1
\to 2 MeV$, thus solving at the same time the strong CP problem and arranging
the grand unification prediction $m_{\mu}/m_{e} = m_{s, Higgs}/m_{d, Higgs}.$
One possible mechanism for this is related to, but not identical with the quark
condensate. Here a mass is generated which is the same for all quarks, and
which adds to the Higgs type mass. Unfortunately, the numerical value of the
generated mass falls short of the desired value (some 5 MeV) by orders of
magnitude. An alternate mechanism, through Higgs-induced left-right couplings
in the squark sector may produce masses of the correct order of magnitude if
the mixing angles are diferent in the squark and quark sectors. To get the
desired result for the $u$ quark mass, we need a stop component mixing of 1/20
for the $LR$ $\tilde{u}$ squark coupling, so the strong CP problem may still be
solved. For the $d$ mass, this mechanism is not really sufficient to solve the
grand unification mass ratio problem.


title: Parton-Hadron duality in QCD sum rules: quantum mechanical examples

abstract:
  Motivated by recent work on three-point QCD sum rules in heavy quark physics,
we use the simple quantum mechanical models to study the basic issue of duality
in three-point sum rules. We show that while in all of these models the duality
in two-point sum rules works fine, the duality in three-point sum rules may be
100%- violated, leading to completely unreliable predictions for the matrix
elements in question. The implications for three-point QCD sum rules are
discussed. A new estimate for the parameter $\lambda_1$ of HQET is given.


title: Rapidity Gaps in e+e- Annihilation and Parton Hadron Duality

abstract:
  We calculate the probability for rapidity gaps in the parton cascade for
different approximations within the perturbative QCD and compare the results
with recent measurements. The aim is to find out whether the dual connection
between the parton and hadron final states -- observed so far in various
inclusive measurements -- holds as well for the extreme kinematic
configurations with colour sources separated by large rapidity gaps. A
description of the data is possible indeed choosing the parameters of the
cascade in the range suggested by recent analyses of the energy spectra (the
$k_\perp$ cutoff $Q_0~\gsim$ QCD scale $\Lambda\sim 250$ MeV).


title: Rescattering Effects in Quarkonium Production

abstract:
  We study eta_c and J/psi hadroproduction induced by multiple scattering off
fixed centres in the target. We determine the minimum number of hard
scatterings required and show that additional soft scatterings may be
factorized, at the level of the production amplitude for the eta_c and of the
cross section for the J/psi. The J/psi provides an interesting example of soft
rescattering effects occurring inside a hard vertex. We also explain the
qualitative difference between the transverse momentum broadening of the J/psi
and of the Upsilon observed in collisions on nuclei. We point out that
rescattering from spectators produced by beam and target parton evolution may
have important effects in J/psi production.


title: Theoretical Study of the \gamma\gamma-->meson-meson Reaction

abstract:
  We present a unified picture which studies simultaneously the gamma
gamma-->pi^+ pi^-, pi^0 pi^0, K^+ K^-, K^0 bar{K}^0, pi^0 eta reactions up to
about sqrt(s)=1.4 GeV reproducing the experimental cross sections. The present
work implements in an accurate way the final state interactions of the
meson-meson system, which is shown to be essential in order to reproduce the
data, particularly the L=0 channel. This latter channel is treated here
following a recent theoretical work in which the meson-meson amplitudes are
well reproduced and the f_0, a_0, sigma resonances show up clearly as poles of
the t matrix. The present work, as done in earlier ones, also incorporates
elements of chiral symmetry and exchange of vector and axial resonances in the
crossed channels, as well as a direct coupling to the f_2(1270) and a_2(1320)
resonances. We also evaluate the decay width of the f_0(980) and a_0(980)
resonances into the gamma-gamma channel.


title:
Scaling Law for Baryon Coupling to its Current and its possible
  applications

abstract:
  The baryon- coupling to its current ($\lambda_{B}$), in conventional QCD sum
rule calculations (QCDSR), is shown to scale as the cubic power of the baryon
mass, $M_B$. Some theoretical justification for it comes from a simple
light-cone model and also general scaling arguments for QCD. But more
importantly, taken as a phenomenological ansatz for the present, this may find
very good use in current explorations of possible applications of QCDSR to
baryon physics both at temperature $T = 0$, $T \ne 0$ and/or density $\rho =
0$, $\rho \ne 0$.


title: CP Violation, Top Quarks and the Tevatron Upgrade

abstract:
  In order to observe a signal of possible CP violation in top-quark couplings,
we study top-quark production and decay under the conditions of the Tevatron
upgrade. Transverse energy asymmetries sensitive to CP violation are defined.
Applying the recently proposed optimal method, we calculate the statistical
significance for the direct observation of CP violation in the production and
subsequent decay of top quarks.


title: Closing the window on the axigluon mass using top quark production data

abstract:
  The contribution of axigluons (the massive color-octet gauge bosons in all
chiral color models) to top quark pair production in hadronic collisions is
considered. The agreement between the experimental values of the ttbar
production cross-section at the TEVATRON and recent QCD predictions is used to
discuss limits on the axigluon mass. Specifically,intermediate mass axigluons,
those in the mass range 50 GeV < M_A < 120 GeV which has not already been
excluded, would increase the tree-level qqbar -> ttbar cross-section by a
factor of >= 2, thereby increasing the theoretical predictions for
sigma_{ttbar} by Delta sigma_{ttbar} = 3.2-3.7 pb (2.7-3.1 pb) using
leading-order (next-to-leading order) parton distributions over this mass
range, independent of the axigluon decay width. Such an increase is roughly
1.3-1.6 (0.9-1.2) standard deviations larger than that suggested by the
apparent good agreement between combined experimental results and recent
theoretical calculations and so is not ruled out, but is definitely disfavored.
Future high-statistics top-quark production runs will likely make a more
definitive statement. The forward-backward asymmetry in ttbar production
induced by axigluons in this mass window is also discussed and found to be
quite large and so could provide another constraint.


title: Fragmentation Functions For Baryons in a Quark-Diquark Model

abstract:
  A perturbative QCD calculation of heavy flavor quark fragmentation into heavy
flavor baryons is developed along the lines of corresponding heavy meson
models. The non-perturbative formation of the baryon is accomplished by
implementing the quark-diquark model of the baryons. Diquark color form factors
are used to enable the integration over the virtual heavy quark momentum. The
resulting spin independent functions for charmed and bottom quarks to fragment
into charmed and bottom baryons with spin 1/2 and 3/2 are compared with recent
data. Predictions are made for the spin dependent fragmentation functions as
well, particularly for the functions $\hat{g}_1$ and $\hat{h}_1$ in the case of
spin 1/2 baryons.


title: Asymmetric Parton Distributions

abstract:
  Applications of perturbative QCD to hard exclusive electroproduction
processes in the Bjorken limit at small invariant momentum transfer t bring in
a new type of parton distributions which have hybrid properties, resembling
both the parton distribution functions and the distribution amplitudes. Their
t-dependence is analogous to that of hadronic form factors. We discuss general
properties of these new parton distributions, their relation to usual parton
densities and the evolution equations which they satisfy.


title: Deeply Virtual Compton Scattering: Facing Nonforward Distributions

abstract:
  Applications of perturbative QCD to deeply virtual Compton scattering process
require a generalization of usual parton distributions for the case when
long-distance information is accumulated in nonforward matrix elements of quark
and gluon operators. We discuss two types of functions parametrizing such
matrix elements: double distributions F(x,y;t) and nonforward distribution
functions \cal F_\zeta (X;t) and also their relation to usual parton densities
f(x).


title:
Recent direct measurement of the Top quark mass and quasi-infrared fixed
  point

abstract:
  We note that the recent direct measurement of the top quark mass at $173.3
\pm 5.6 (stat) \pm 6.2 (syst)$ by D0 collaboration severely constrains the
theoretically attractive infra-red fixed point scenario of the top quark Yukawa
coupling in supersymmetric GUTs. For one-step unified models the above
mentioned measurement bounds the arbitrary but experimentally determinable
parameter $\tan \beta$ to the range $1.3 \le \tan \beta \le 2.1$. Further
crunch on the top quark mass may determine $\tan \beta$ even more accurately
within the fixed point scenario. On the other hand an experimental value of
$\tan \beta > 2.1$ will rule out the fixed point scenario bounding
$h^2_t(M_X)/4 \pi$ to 0.022 from above.


title:
Effects of 126 dimensional Higgs scalar on Bottom-Tau unification and
  quasi-infrared fixed point

abstract:
  In the presence of ${\bf 126 + \bar{126}}$ Higgs multiplets in a SO(10)
theory, the fermion masses get contributions from an induced vacuum expectation
value (VEV) of a $SU(2)_L$ doublet residing in ${\bf 126}$ which differentiates
between quarks and leptons by a relative sign leading to a significant
correction to the prediction of the mass ratio of the bottom quark and the tau
lepton for ranges of the mass of this extra doublet. We perform a two-loop
renormalization group analysis of the minimal version of the one-step
supersymmetric SO(10) model to display this and re-calculate the corrections to
the top quark mass in the presence of such an induced VEV. We show that these
effects make the infra-red fixed point scenario consistent with experimental
results.


title: QCD Phenomenology of Charm Production at HERA

abstract:
  We compare different schemes for the treatment of heavy quark production in
Deep-Inelastic Scattering (DIS). For fully-integrated quantities such as
$F_{2}(x,Q^{2})$, we advocate the use of the General-Massive
Variable-Flavor-Number (GM-VFN) scheme; we present some results showing the
progress of a Next-to-Leading Order calculation in this scheme. For
differential quantities, the Fixed-Flavor-Number (FFN) scheme provides a more
appropriate starting point. We present a new calculation of the azimuthal
distribution of charm quark production in DIS. All results have been obtained
using a Monte Carlo program under development.


title: Neutrino mass matrix with U(2) flavor symmetry and neutrino oscillations

abstract:
  The three neutrino mass matrices in the $SU(5)\times U(2)$ model are studied
focusing on the neutrino oscillation experiments. The atmospheric neutrino
anomaly could be explained by the large $\nu_{\mu} - \nu_{\tau}$ oscillation.
The long baseline experiments are expected to detect signatures of the neutrino
oscillation even if the atmospheric neutrino anomaly is not due to the neutrino
oscillation. However, the model cannot solve the solar neutrino deficit while
it could be reconciled with the LSND data.


title: Soft Colour Interactions and Diffractive DIS

abstract:
  The basic ideas and some results of the semiclassical approach to diffractive
DIS are briefly described. In the production of high-$p_{\perp}$ jets
boson-gluon fusion is predicted to be the dominant partonic process. The
$p_{\perp}$-spectrum and the two-jet invariant mass distribution provide a
clear test of the underlying `hard' partonic process and the `soft' mechanism
of colour neutralization.


title:
Study of CP Violation: Electroweak Baryogenesis and Anomalous W-Boson
  Couplings

abstract:
  The contributions from the Ochanomizu CP Study Group to the KEK meetings on
"CP violation and its origin" (1993-1997) are summarized on electroweak
baryogenesis and anomalous W-boson couplings. We survey planned new experiments
which could examine some aspects studied in our contributions. We also discuss
several issues on baryogenesis. Ten problems are presented for further studies.


title: Electric Dipole Moments of Neutron and Electron in Supersymmetric Model

abstract:
  The electric dipole moments (EDMs) of the neutron and the electron are
reviewed within the framework of the supersymmetric standard model (SSM) based
on grand unified theories coupled to N=1 supergravity. Taking into account
one-loop and two-loop contributions to the EDMs, we explore SSM parameter space
consistent with experiments and discuss predicted values for the EDMs.
Implications of baryon asymmetry of our universe for the EDMs are also
discussed.


title: Penguin Diagrams, Charmless B-Decays and the ``Missing Charm Puzzle''

abstract:
  We calculate the contributions of penguin diagrams with internal u or c
quarks to various inclusive charmless B-decay rates. Further we analyze the
influence of the chromomagnetic dipole operator Q_8 on these rates. We find
that the rates corresponding to B-bar --> X_{u u-bar s}, B-bar --> X_{d d-bar
s}, B-bar --> X_{s s-bar s}, B-bar --> X_{s s-bar d} and B --> X_{d d-bar d}
are dominated by the new penguin contributions. The contributions of Q_8
sizably diminish these rates. Despite of an increase of the total charmless
decay rate by 36 % the new contributions are not large enough to explain the
charm deficit observed by ARGUS and CLEO. We predict n_c=1.33 +/- 0.06 for the
average number of charmed particles per B-decay in the Standard Model. Then the
hypothesis of an enhancement of the chromomagnetic dipole coefficient C_8 by
new physics contributions is analyzed. We perform a model independent fit of
C_8 to the experimental data. If the CKM structure of the new physics
contribution is the same as in the Standard Model, |C_8(M_W)| must be enhanced
by a factor of 9 to 16 in order to explain the observed charm deficit.


title: Hadron Structure Functions from Lattice QCD -- 1997

abstract:
  We review the status of lattice calculations of the deep-inelastic structure
functions of the nucleon. In addition, we present some results on the pion and
rho structure functions.


title: Deep Inelastic Structure Functions in Bag-Like Models

abstract:
  A new method of calculating deep inelastic structure functions for the
nucleon in independent particle models is presented. The method is applied to
the bag-like model and its predictions are compared with the parametrisation of
Gluck, Reya and Vogt.


title:
Signatures of Absorption Mechanisms for J/psi and psi' Production in
  High-Energy Heavy-Ion Collisions

abstract:
  J/psi and psi' produced in high-energy heavy-ion collisions are absorbed by
their collisions with nucleons and produced soft particles, leading to two
distinct absorption mechanisms. The signature of absorption by produced soft
particles, as revealed by psi' production data, consists of a gap and a change
of the slope in going from the pA line to the nucleus-nucleus line when we make
a semi-log plot of the survival probability as a function of the path length.
Using this signature, we find from the J/psi production data in pA, O-Cu, O-U,
and S-U collisions that the degree of J/psi absorption by produced soft
particles is small and cannot account for the J/psi data in Pb-Pb collisions.
The anomalous suppression of J/psi production in Pb-Pb collisions can be
explained as due to the occurrence of a new phase of strong J/psi absorption,
which sets in when the local energy density exceeds about 3.4 GeV/fm^3. To
probe the chemical content of the new phase, we propose to study the abundance
of open-charm mesons and charm hyperons which depends sensitively on the quark
chemical potential.


title:
Diffractive rho-meson Leptoproduction on Polarized Nucleon as a Way to
  Measure the Polarized Gluon Distribution

abstract:
  The amplitude of diffractive $\rho$ (and open quark) leptoproduction on a
polarized target is calculated in the leading log approximation of pQCD using
the hadron-parton duality hypothesis. The spin-spin asymmetry is expressed in
terms of the spin dependent gluon and quark structure functions in the small
$x$ region. Therefore the $\gamma^*+p\to \rho +p$ reaction provides a promising
tool to study the spin dependent gluon distribution $\Delta G(x,q^2)$.


title: Testing Deca-TeV Unified Compositeness at the 4 TeV mu+mu- Collider

abstract:
  In the framework of the unified compositeness of leptons, quarks and Higgs
bosons, the hidden local symmetry \hat H_{loc}= SU(2)_L\times U(1)_Y with the
heavy composite vector bosons, in addition to the SM gauge bosons, is briefly
described. Supplementary hypothesis of the vector boson dominance (VBD) of the
SM gauge interactions is considered. It is argued that this should produce the
universal dominant residual interactions of the SM composite particles, i.e.,
all of the fermions and Higgs bosons. Restrictions on the universal residual
fermion-fermion, fermion-boson and boson-boson interactions due to the VBD are
investigated. Manifestations of the residual interactions at the 4 TeV mu+mu-
collider are studied. It is shown that at 95% C.L. the unified substructure
could be investigated at the collider in the processes mu+mu- \to \bar ff up to
the compositeness scale O(150 TeV), in the processes mu+mu- \to ZH, W+W- up to
O(100 TeV) and in the process mu+mu- \to ZHH up to O(40 TeV), which lie in the
naturally preferable Deca-TeV region.


title: Unified description of light- and strange-baryon spectra

abstract:
  We present a chiral constituent quark model for light and strange baryons
providing a unified description of their ground states and excitation spectra.
The model relies on constituent quarks and Goldstone bosons arising as
effective degrees of freedom of low-energy QCD from the spontaneous breaking of
chiral symmetry. The spectra of the three-quark systems are obtained from a
precise variational solution of the Schr\"odinger equation with a
semirelativistic Hamiltonian. The theoretical predictions are found in close
agreement with experiment.


title: Physics at the Photon Linear Collider

abstract:
  The physics prospects of the high energy Photon Linear Collider are reviewed,
emphasizing its potential to study the symmetry breaking sector, including
Higgs searches and precision anomalous W couplings measurements.


title:
Neutralino Dark Matter in Minimal Supergravity: Direct Detection vs.
  Collider Searches

abstract:
  We calculate expected event rates for direct detection of relic neutralinos
as a function of parameter space of the minimal supergravity model. Numerical
results are presented for the specific case of a $^{73}$Ge detector. We find
significant detection rates ($R> 0.01$ events/kg/day) in regions of parameter
space most favored by constraints from $B\to X_s\gamma$ and the cosmological
relic density of neutralinos. The detection rates are especially large in
regions of large $\tan\beta$, where many conventional signals for supersymmetry
at collider experiments are difficult to detect. If the parameter $\tan\beta$
is large, then there is a significant probability that the first direct
evidence for supersymmetry could come from direct detection experiments, rather
than from collider searches for sparticles.


title: Bounds on R-Parity Violating Parameters from Fermion EDM's

abstract:
  We study one-loop contributions to the fermion electric dipole moments in the
Minimal Supersymmetric Standard Model with explicit R-parity violating
interactions. We obtain new individual bounds on R-parity violating Yukawa
couplings and put more stringent limits on certain parameters than those
obtained previously.


title:
Next-to-leading Order Evolution of Transversity Distributions and
  Soffer's Inequality

abstract:
  We present a calculation of the two-loop splitting functions for the
evolution of the twist-2 `transversity' parton densities of transversely
polarized nucleons. We study the implications of our results for Soffer's
inequality for the case of valence quark densities.


title:
Desperately Seeking Non-Standard Phases via Direct CP Violation in $b\to
  sg^\ast$ Process

abstract:
  Attributing the recent CLEO discovery of $B \to \eta' + X_s$ to originate
(primarily) from the fragmentation of an off-shell gluon ($g^*$) via $b \to s +
g^*$, $g^* \to g + \eta'$, we emphasize that many such states ($X_g$) should
materialize. Indeed the hadronic fragments ($X_g$) of $g^*$ states are closely
related to those seen in $\psi \to \gamma (\phi, \omega) + X_g$. A particular
final state of considerable interest is $X_g=K^+K^-$. Signals from such states
in $B$ decays can be combined to provide a very sensitive search for CP
violating phase(s) from non-standard physics. The method should work even if
the contribution of these source(s) to the rates is rather small ($\sim10%$) to
the point that a comparison between theory and experiment may find it extremely
difficult to reveal the presence of such a new physics.


title: Primordial Magnetic Fields from Superconducting Cosmic Strings

abstract:
  Cosmic strings are stable topological defects that may have been created at a
phase transition in the early universe. It is a growing belief that, for a wide
range of theoretical models, such strings may be superconducting and carry
substantial currents which have important astrophysical and cosmological
effects. This paper explores the possibility of generation of a primordial
magnetic field by a network of charged-current carrying cosmic strings. The
field is created by vorticity, generated in the primordial plasma due to the
strings' motion and gravitational pull. In the case of superconducting strings
formed at the breaking of grand unification, it is found that strong magnetic
fields of high coherence can be generated in that way. Such fields could
account for the observed galactic and intergalactic magnetic fields since they
suffice to seed magnetic dynamos on galactic scales.


title: Isotopic Spin Conservation Effect in Bose-Einstein Correlations

abstract:
  Bose-Einstein correlations of pions have been calculated in the presence of
both statistical and coherent pion production with isotopic spin conservation
taken into account.An additional contribution to pion correlation function has
been found arising due to isospin effect


title: Infra-Red Finite Charge Propagation

abstract:
  The Coulomb gauge has a long history and many uses. It is especially useful
in bound state applications. An important feature of this gauge is that the
matter fields have an infra-red finite propagator in an on-shell
renormalisation scheme. This is, however, only the case if the renormalisation
point is chosen to be the static point on the mass shell, p = (m, 0, 0, 0). In
this letter we show how to extend this key property of the Coulomb gauge to an
arbitrary relativistic renormalisation point. This is achieved through the
introduction of a new class of gauges of which the Coulomb gauge is a limiting
case. A physical explanation for this result is given.


title:
POLRAD 2.0. FORTRAN code for the Radiative Corrections Calculation to
  Deep Inelastic Scattering of Polarized Particles

abstract:
  The FORTRAN code POLRAD 2.0 for radiative correction calculation in inclusive
and semi-inclusive deep inelastic scattering of polarized leptons by polarized
nucleons and nuclei is described. Its theoretical basis, structure and
algorithms are discussed in details.


title: Radiation of two hard gluons in e+e- ---> q (bar)q

abstract:
  The process e+e- ---> q(bar) q g g where all final particles are hard is
treated in a semi-analytic approach. Cuts on the invariant masses of the quark
and the gluon pair can be applied. The total cross section is obtained by three
numerical integrations.


title:
The asymptotics of the transition form factor \gamma\gamma* -> pi^o and
  QCD sum rules

abstract:
  In this paper we present the result of a direct QCD sum rule calculation of
the transition form factor \gamma\gamma* -> pi^o in the region of moderately
large invariant momentum Q^2 > 1GeV^2 of the virtual photon. In contrast to
pQCD, we make no assumptions about the shape of the pion distribution amplitude
\phi_\pi(x). Our results agree with the Brodsky-Lepage proposal that the
Q^2-dependence of this form factor is given by an interpolation between its
Q^2=0 value fixed by the axial anomaly and 1/Q^2 pQCD behaviour for large Q^2,
with normalization corresponding to the asymptotic form \phi_\pi^as (x)=6 f_\pi
x (1-x) of the pion distribution amplitude. Our prediction for the from factor
$F_{\gamma^*\gamma^*\pi^\circ}(q_1^2 = 0,q_2^2 = -Q^2)$ is in good agreement
with new CLEO data.


title: R-parity violation and the New Events at HERA

abstract:
  We summarise possible explanations of the HERA large-Q^2 data, in the
framework of R-parity violating supersymmetry. Experimental limits indicate
that the most likely production channels are e^+ d --> scharm_L, e^+ d --> stop
and e^+ s --> stop. We study the regions of the parameter space that lead to
consistent branching ratios, with and without the unification condition for
gaugino masses. Cancellations in the coupling of the lightest neutralino to
scharm_L, result in a balance between R-parity violating and R-parity
conserving decay modes. Such cancellations are not present in the coupling of
the neutralino with other particles and an interesting case is sneutrino_L,
which could be produced at LEP2 via an L_1L_{2,3}{E}_1^c operator. On the other
hand, the stop branching ratios depend mainly on the mass of the lightest
chargino and tend to be dominated by either the R-conserving or the R-violating
mode.


title:
The Hadronic Recoil Mass Spectrum in Semileptonic B Decays and
  Extracting |V_{ub}| in a Model-Insensitive Way

abstract:
  We present an extended discussion of the previously noted possibility to
extract |V_{ub}| from an analysis of the hadronic recoil mass spectrum in
B->X_u l nu decays. Invariant mass spectra containing perturbative as well as
nonperturbative corrections are given; their shape is manifestly sensitive to
the three basic quantities mu_pi^2, m_b, and alpha_s$, whereas the total
integrated rate is much less so. Only a small fraction of b->u transitions
generates a recoil mass M_X of at least M_D. We find that the fraction of
events with M_X < 1.5 GeV (to reject leakage from b->c) exhibits fairly little
dependence on mu_pi^2, m_b and alpha_s; |V_{ub}| can then be extracted in a
largely model-insensitive way. This conclusion is based on the applicability of
the OPE to actual semileptonic B decays. A direct cross-check of this
assumption and a determination of the required basic parameters of the heavy
quark expansion will be possible in the future with more experimental data.


title: Construction and Consequences of Coloured Charges in QCD

abstract:
  This talk reports on work aimed at improving our understanding of charged
states in gauge theories.Emphasis is placed on different ways of
implementingthe gauge invariance of physical states. QED perturbative
calculations are used to stress that gauge invariance is not enough: only a
subset of such states have a direct physical significance. In QCD a
non-perturbative obstruction means that quarks and gluons cannot form physical
states and as such these particles are not truely observables. This sets a
fundamental limit on the constituent quark model.


title:
Measuring Polarized Gluon and Quark Distributions with Meson
  Photoproduction

abstract:
  We calculate polarization asymmetries in photoproduction of high transverse
momentum mesons, focusing on charged pions, considering the direct,
fragmentation, and resolved photon processes. The results at very high meson
momentum measure the polarized quark distributions and are sensitive to
differences among the existing models. The results at moderate meson momentum
are sensitive to the polarized gluon distribution and can provide a good way to
measure it. Suitable data may come as a by-product of deep inelastic
experiments to measure $g_1$ or from dedicated experiments.


title:
Some O(\alpha^2) Annihilation Type Contributions to the Orthopositronium
  Width

abstract:
  We consider some radiative corrections to the lowest order annihilation
diagram for the orthopositronium decay rate. The insertion of the renormalized
vertex correction in the annihilation graph gives $1.6283 (\alpha/\pi)^2
\Gamma_0$. We compute also the contribution of the square of the lowest order
annihilation amplitude, which turns out to be $0.1702 (\alpha/\pi)^2 \Gamma_0$.
Finally, we obtain a term $\alpha^2 \ln\alpha \Gamma_0$ arising from the
correction to the light-light scattering block due to the exchange of one
coulombic photon, in agreement with earlier computations.


title: CP and B Physics: Progress and Prospects

abstract:
  This summary of the 2nd International Conference on B Physics and CP
Violation (Honolulu, 24--27 March, 1997) contains, in addition to what is
implied in the title, some extended remarks on the limitations of theory as
well as speculations regarding nonperturbative enhancement of decay modes of
the class b -> s + charmless hadrons.


title:
A microscopic calculation of secondary Drell-Yan production in heavy ion
  collisions

abstract:
  A study of secondary Drell-Yan production in nuclear collisions is presented
for SPS energies. In addition to the lepton pairs produced in the initial
collisions of the projectile and target nucleons, we consider the potentially
high dilepton yield from hard valence antiquarks in produced mesons and
antibaryons. We calculate the secondary Drell-Yan contributions taking the
collision spectrum of hadrons from the microscopic model URQMD. The
contributions from meson-baryon interactions, small in hadron-nucleus
interactions, are found to be substantial in nucleus-nucleus collisions at low
dilepton masses. Preresonance collisions of partons may further increase the
yields.


title: W and Z transverse momentum distributions: resummation in qT-space

abstract:
  We describe an alternative approach to the prediction of W and Z transverse
momentum distributions based on an extended version of the DDT formula. The
resummation of large logarithms, mandatory at small qT, is performed in
qT-space, rather than in the impact parameter b. The leading, next-to-leading
and next-to-next-to-leading towers of logarithms are identical in the b-space
and qT-space approaches. We argue that these terms are sufficient for W and Z
production in the region in which perturbation theory can be trusted. Direct
resummation in qT-space provides a unified description of vector boson
transverse momentum distributions valid at both large and small qT.


title: Naive dimensional analysis and truly strong interactions

abstract:
  We question whether the canonical estimate of a strong coupling, \alpha
\approx 4\pi, is always appropriate for dynamical symmetry breaking. Our
discussion is motivated by the success of naive quark models in describing low
energy QCD.


title: Squeezed condensate of gluons and the mass of the eta'

abstract:
  The relation between the large mass of the $\eta'$ and the structure of the
gluon vacuum via the $U_A(1)$ anomaly is discussed. A squeezed gluon vacuum is
considered as an alternative to existing models. Considering Witten's formula
for the $\eta_0$ mass we show that the contact term can give a sizable
contribution and relate it to the physical gluon condensate. The values of the
gluon condensate obtained through this relation are compared with the value by
Shifman, Vainshtein and Zakharov and the recent update values by Narison.