title: On Spin Independence in Large $N_c$ Baryons

abstract:
  We argue directly from Witten's analysis of large $N_c$ baryons that the
structure of the $s$-wave low-spin baryon states in QCD becomes
spin-independent as $N_c\rightarrow\infty$. This property leads to $SU(6)$-like
behavior of static matrix elements, such as the axial-vector current matrix
elements recently studied by Dashen, Manohar and Jenkins. Our analysis suggests
a method for applying large $N_c$ results for $N_c=3$, even though the baryon
states for large $N_c$ are very different.


title: Particle Astrophysics from the Particle Perspective

abstract:
  In this talk I discuss several topics at the interface of particle physics
and astrophysics/cosmology. These include the problem of dark matter and two
popular dark matter candidates: axions and neutralinos. I also discuss briefly
some recent developments in electroweak baryogenesis, as well as a variety of
somewhat more exotic topics: the fate of domain walls, axinos, non-vanishing
cosmological constant, and cosmological constraints on models with dynamical
supersymmetry breaking. Most of the material is review, however a few of the
remarks, especially regarding axion cosmology in the framework of
supersymmetry, I believe to be original.


title:
Four Fermion Processes at Future $e^+e^-$ Colliders as a Probe of New
  Resonant Structures

abstract:
  Possible oblique effects from vector particles that are strongly coupled to
the known gauge bosons are calculated for the case of final hadronic states
produced at future $e^+e^-$ colliders, using a formalism that was recently
proposed and that exploits the information and the constraints provided by LEP
1 results. Combining the hadronic channels with the previously analysed
leptonic ones we derive improved limits for the masses of the resonances
that,in technicolour-like cases, would range from one to two TeV for a 500 GeV
linear collider, depending on the assumed theoretical constraints.


title: Neutrino Masses and Mixing

abstract:
  Restrictions on the neutrino masses and lepton mixing are reviewed. Solar,
atmospheric and relic neutrinos give the indications of existence of nonzero
neutrino masses and mixing. The data pick up two regions of mixing angles which
are or appreciably larger or appreciably smaller than the Cabibbo angle. Some
theoretical schemes with {\it large} or {\it small} lepton mixing are
discussed.


title: Baryons from Quarks in the $1/N$ Expansion

abstract:
  We present a diagrammatic analysis of baryons in the $1/N$ expansion, where
$N$ is the number of QCD colors. We use this method to show that there are an
infinite number of degenerate baryon states in the large-$N$ limit. We also
show that forward matrix elements of quark bilinear operators satisfy the
static quark-model relations in this limit, and enumerate the corrections to
these relations to all orders in $1/N$. These results hold for any number of
light quark flavors, and the methods used can be extended to arbitrary
operators. Our results imply that for two flavors, the quark-model relations
for the axial currents and magnetic moments get corrections of order $1/N^2$.
For three or more flavors, the results are more complicated, and corrections
are generically of order $1/N$. We write an explicit effective lagrangian which
can be used to carry out chiral perturbation theory calculations in the $1/N$
expansion. Finally, we compare our results to what is expected from a chiral
constituent quark model.


title: Magnetic Monopoles in the Einstein-Yang-Mills-Higgs System

abstract:
  We study the Yang-Mills-Higgs system within the framework of general
relativity. In the static situation, using Bogomol'nyi type analysis, we derive
a positive-definite energy functional which has a lower bound. Specializing to
the gauge group $SU(2)$ and the t'Hooft-Polyakov ansatz for the gauge and Higgs
fields, we seek static, spherically symmetric solutions to the coupled system
of equations in both the isotropic and standard coordinate systems. In both
cases, in the spontaneously broken symmetry situation, we find great
simplications reducing the solutions of the coupled system to the solution of a
single non-linear differential equation, different one in each case, but
well-known in other contexts of physics. We find abelian and non-abelian
monopole solutions with gravitational fields playing the role of Higgs fields
in providing attraction that balances the repulsion due to the gauge fields.
Numerical solutions indicate the possibility of blackhole horizons inside the
monopoles enclosing the singularity at the origin. Such non-abelian monopoles
are then the analogs of Reissner-Nordstr\"om blackholes with magnetic charge.


title: Natural Doublet-Triplet Splitting in Supersymmetric SO(10) Model

abstract:
  We construct a supersymmetric SO(10) model, where natural doublet-triplet
splitting implemented via the Dimopoulos-Wilczek mechanism is stable under the
addition of 126+\bar{126} Higgs superfields needed to generate the small
neutrino masses via the see-saw mechanism and where both the charged fermion
and neutrino masses arise from just one set of 10 and \bar{126} multiplets.


title: On the Higher Order Corrections to Heavy Quark Effective Theory

abstract:
  We show that the different ways of deriving the Heavy Quark Effective Theory
(HQET) lead to equivalent theories. The equivalence can be established through
a careful redefinition of the field variables. We demonstrate the equivalence
to order ${1 \over m^5}$ in the presence of a constant electric field.


title: Nonperturbative Decoupling and Effective Field Theory

abstract:
  We examine recent claims that nonperturbative effects can prevent the
decoupling of a heavy fermion whose mass arises from a Yukawa coupling to a
scalar field. We show that in weakly coupled, four dimensional models such as
the standard model with heavy mirror fermions the effects of the heavy fermions
can always be accounted for by {\it local} operators involving light fields. We
contrast this with the case of the 1+1 dimensional Abelian Higgs model, in
which there does not appear to be a local effective field theory describing the
low energy physics when heavy fermions are integrated out. (Mailer corruption
hopefully fixed!)


title:
Spontaneous Breaking of R parity in the Minimal Supersymmetric Standard
  Model Revisited

abstract:
  We reconsider the possibility of spontaneous breaking of $R$ parity in the
Minimal Supersymmetric Standard Model. By a renormalization group analysis we
find the parameter space in which a sneutrino gets a vacuum expectation value,
leading to the spontaneous breaking of the lepton number and to the appearance
of a phenomenologically unacceptable massless Goldstone boson. We then analyze
the effect of operators giving rise to a tiny amount of explicit violation of
lepton number, which could emerge as remnants of physics at some superheavy
(Planck or GUT) scale in the low energy effective theory. We show that the
conspiracy between the spontaneous and the explicit breaking scales can provide
a mass to the Goldstone boson larger than the ${\rm Z}^0$ boson mass, hence
allowing for a non vanishing sneutrino vacuum expectation value without
increasing the invisible width of the ${\rm Z}^0$.


title:
Asymmetry of the Missing Momentum Distribution in (e,e$'$p) Reactions
  and Color Trnasparency

abstract:
  We suggest the measurement of the integrated asymmetry of teh missing
momentum distribution in (e,e$'$p)reactions to check color transparency effects
at intermediate momentum transfers.


title:
Final-state \pi\pi interactions in
  \Upsilon(3S)\rightarrow\Upsilon(1S)\pi\pi

abstract:
  The $m_{\pi\pi}$ spectrum and various angular distributions in $\upss$ are
studied including the effects of the $\pi\pi$ phase shift in the $I=L=0$
channel using the lowest order amplitude in the pion momentum expansion. Our
results are compared with the recent CLEO data, and we find good agreement
except for the $\cos\theta_{\pi}^*$ distributions. We argue that the
$\cos\theta_{\pi}^*$ distribution, contrary to other distributions, is
sensitive to the higher order corrections in the pion momentum expansion. This
argument is supported by using an ansatz for the amplitude which is of higher
order in the pion momentum expansion and still satisfies the soft pion theorem.


title:
Hadron and Quark Form Factors in the Relativistic Harmonic Oscillator
  Model

abstract:
  Nucleon, pion and quark form factors are studied within the relativistic
harmonic oscillator model including the quark spin. It is shown that the
nucleon charge, magnetic and axial form factors and the pion charge form factor
can be explained with one oscillator parameter if one accounts for the scaling
rule and the size of the constituent quarks.


title: The alpha_s^3 correction to Gamma (Z^0 -> hadrons)

abstract:
  We present the alpha_s^3 correction to the Z^0 decay rate into hadrons in the
limit m_top >> m_Z.


title: The 1/N Expansion for Baryons

abstract:
  A systematic expansion in 1/N is constructed for baryons in QCD. Predictions
of the 1/N expansion at leading and subleading order for baryon axial current
coupling constant ratios such as F/D, baryon masses and magnetic moments are
derived. The baryon sector of QCD has a light quark spin-flavor symmetry at
leading order in 1/N. The formalism of induced representations for contracted
Lie algebras is introduced to explain the consequences of this symmetry.
Relations are first derived for the simplest case of two light flavors of
quarks. The generalization of the large N expansion to N_f = 3 flavors is
subtle and is treated using several complementary methods. The 1/N expansion
severely restricts the form of SU(3) breaking in the baryon sector.
Extrapolation of the large N results to N=3 permits quantitative comparison
with experimental data. Deviations of the measured quantities from exact
spin-flavor symmetry predictions are accurately described by the subleading 1/N
corrections. Implications of the 1/N expansion for baryon chiral perturbation
theory are discussed.


title: Penguin Effects on K Pi and PiPi Decays of the $B$ Meson

abstract:
  We give the detailed analyses for the gluonic-penguin effect on the $\kp$ and
$\pp$ decays of the $B$ meson. In the standard model, it is shown that the
ratio $BR(B\A\kp)/BR(B\A\pp)$ takes the value $0.5\sim 3.0$ with the strongly
depending on the CP violating phase $\phi$ and the KM matrix element
$|V_{ub}|$. We obtain the constraint on the form factor by using the
experimental branching ratio. It is also found that, in the two-Higgs-doublet
model, the charged Higgs contribution which could enhance the $B\A X_s\r$ decay
does not a sizable effect on our processes. The effect of the final state
interaction on these processes is also discussed.


title: Small $x$ and Small $Q^2$

abstract:
  I discuss (i) hadron-hadron and photon-hadron total cross-sections, (ii)
elastic scattering, (iii) the r\^{o}le of minijets in total cross-sections and
the need to include them in Monte-Carlos for small-$x$ structure functions,
(iv) how the two pomerons affect small-$x$ behaviour, and (v) rapidity-gap
physics.


title: Charged Particle Scattering from Electroweak and Semi-Local Strings

abstract:
  The scattering of a charged fermion from an electroweak or semi-local string
is investigated and a full solution obtained for both massive and massless
cases. For the former, with fractional string flux, there is a helicity
conserving and helicity-flip cross-section, of equal magnitude and of a
modified Aharonov-Bohm form: for integer flux the strong interaction
cross-section is suppressed by a logarithmic term. The results also apply for
GUT cosmic strings and chiral fermions.


title: Global Strings and the Aharonov-Bohm Effect

abstract:
  When a fermion interacts with a global vortex or cosmic string a solenoidal
"gauge" field is induced. This results in a non-trivial scattering
cross-section. For scalars and non-relativistic fermions the cross-section is
similar to that of Aharonov and Bohm, but with corrections. A cosmological
example is compared to one in liquid He$^{3}$-A and important differences are
discovered.


title: Neutrinoless Double Beta Decay and the Solar Neutrino Problem

abstract:
  The MSW or vacuum oscillation solution of the solar neutrino problem can be
reconciled with possible existence of the $(\beta\beta)_{0\nu}$ decay with a
half-life corresponding to an effective Majorana mass of the electron neutrino
$|m_{ee}| \cong (0.1 - 1.0)~$eV. The phenomenological consequences of such a
possibility are analyzed and the implications for the mechanisms of neutrino
mass generation are considered.


title:
Gluon Distribution Functions for Very Large Nuclei at Small Transverse
  Momentum

abstract:
  We show that the gluon distribution function for very large nuclei may be
computed for small transverse momentum as correlation functions of an
ultraviolet finite two dimensional Euclidean field theory. This computation is
valid to all orders in the density of partons per unit area, but to lowest
order in $\alpha_s$. The gluon distribution function is proportional to $1/x$,
and the effect of the finite density of partons is to modify the dependence on
transverse momentum for small transverse momentum.


title:
Weak Decays Of Charm Hadrons: The Next Lesson On QCD -- And Possibly
  More!

abstract:
  Second-generation theoretical technologies -- heavy quark expansions, QCD sum
rules and QCD simulations on the lattice -- are arriving on the scene, allowing
a treatment of charm decays that is genuinely based on QCD. The availability of
those theoretical tools strengthens the case for the need for comprehensive
precision measurements of charm decays. It is pointed out that the decays of
charm mesons as well as of charm baryons have to be systematically analysed to
gain control over theoretical uncertainties. A $\tau$-charm factory with
$E_{c.m.}\leq 5.5$ GeV is optimally suited for such a program. It would lead to
a deeper understanding of QCD that would also prepare us better for exploiting
the discovery potential anticipated in beauty decays. In addition it is quite
conceivable (though certainly not guaranteed) that there arise fundamental
surprises, such as non-canonical rare $D$ decays, $D^0$-$\bar D^0$ oscillations
and CP violation in charm decays which would dramatically alter our perspective
on Nature's fundamental forces.


title:
$b \rightarrow s \gamma$ and $\epsilon_b$ Constraints on Two Higgs
  Doublet Model

abstract:
  We perform a combined analysis of two stringent constraints on the 2 Higgs
doublet model, one coming from the recently announced CLEO II bound on $B(b
\rightarrow s \gamma)$ and the other from the recent LEP data on $\epsilon_b$.
We have included one-loop vertex corrections to $Z \rightarrow b \overline b$
through $\epsilon_b$ in the model. We find that the new $\epsilon_b$ constraint
excludes most of the less appealing window $\tan\beta\lsim 1$ at $90\%$C.~L.
for $m_t=150\GeV$. We also find that although $b \rightarrow s \gamma$
constraint is stronger for $\tan\beta>1$, $\epsilon_b$ constraint is stronger
for $\tan\beta\lsim 1$, and therefore these two are the strongest and
complimentary constraints present in the charged Higgs sector of the model.


title: Large $p_{\perp}$ Exclusive Processes:RECENT Developments

abstract:
  Recent improvements of the hard scattering picture for exclusive reactions,
namely the inclusion of both Sudakov corrections and the intrinsic transverse
momentum dependence of the hadronic wave function, are reviewed. On account of
these improvements the perturbative contribution to the pion's form factor can
be calculated in a theoretically self-consistent way for momentum transfers as
low about $2\,{\rm GeV}$. This is achieved at the expense of a substantial
suppression of the perturbative contribution in the few GeV region. Eventual
higher twist contributions are also discussed.\\


title: Issues in Light Hadron Spectroscopy

abstract:
  A high priority in light spectroscopy is to seek out and characterize various
types of non-$(Q\bar{Q}$) meson. The large quantity of new data now appearing
will present a great opportunity. To identify the non-$(Q\bar{Q}$) intruders
one needs to know the regular $(Q\bar{Q}$) pattern well; whole meson families
thus become a target for close investigation. A powerful discovery strategy is
to observe the same meson in a variety of reactions. Because mesons appear as
resonances, other dynamics can distort the signal in a particular decay
channel. Unitarity is the master principle for co- ordinating various sightings
of the same resonance. Much of the new spectroscopic information in prospect
will come from inferring two-body dynamics from three-body final states.
Conventional methods of analysis via the isobar model use approximations to
unitarity that need validation. Of all the meson families, the scalars should
be a prime hunting ground for non-$(Q\bar{Q}$)'s. Even before the advent of the
new results, some revisions of the `official' classifications are urged. In
particular, it is argued that the lightest broad $I=0$ scalar is a very broad
$f_0$ (1000). One unfinished task is to decide whether $f_0$ (975) and $a_0$
(980) are alike or different; several non-$(Q\bar{Q}$) scalar scenarios hinge
on this. To settle this, much better data


title: Evaluating Sums over the Matsubara Frequencies

abstract:
  Perturbative calculations in field theory at finite temperature involve sums
over the Matsubara frequencies. Besides the usual difficulties that appear in
perturbative computations, these sums give rise to some new obstacles that are
carefully analized here. I present a fast and realible recipe to work out sums
over the Matsubara frequencies. As this algorithm leads to deal with very
cumbersome algebraic expressions, it has been written for computers by using
the symbolic manipulation program Mathematica. It is also shown this algorithm
to be self-consistent when it is applied to more than one loop computations.


title: The Generalized Simplified Parton Shower Model

abstract:
  We explore the consequences of considering clans real physical objects in the
framework of a generalized version of the Simplified Parton Shower model for a
single jet. We predict that the average number of clans at fixed energy grows
linearly in rapidity and slowly decreases with energy in a fixed rapidity
interval.


title: Heavy Flavor Theory: Overview

abstract:
  An introduction to the heavy quark effective theory and its symmetries is
given. Some implications of the heavy quark spin and flavor symmetries are
discussed. Recent results on fragmentation to quarkonium states are reviewed.


title: One Loop Multiphoton Helicity Amplitudes

abstract:
  We use the solutions to the recursion relations for double-off-shell fermion
currents to compute helicity amplitudes for $n$-photon scattering and
electron-positron annihilation to photons in the massless limit of QED. The
form of these solutions is simple enough to allow {\it all}\ of the
integrations to be performed explicitly. For $n$-photon scattering, we find
that unless $n=4$, the amplitudes for the helicity configurations (+++...+) and
(-++...+) vanish to one-loop order.


title:
Solar Model Uncertainties, MSW Analysis, and Future Solar Neutrino
  Experiments

abstract:
  Various theoretical uncertainties in the standard solar model and in the
Mikheyev-Smirnov-Wolfenstein (MSW) analysis are discussed. It is shown that two
methods of estimating the solar neutrino flux uncertainties are equivalent: (a)
a simple parametrization of the uncertainties using the core temperature and
the nuclear production cross sections; (b) the Monte Carlo method of Bahcall
and Ulrich. In the MSW analysis, we emphasize proper treatments of correlation
of theoretical uncertainties between flux components and between different
detectors, the Earth effect, and multiple solutions in a combined $\chi^2$
procedure. The MSW solutions for various standard and nonstandard solar models
are also shown. The MSW predictions of the global solutions for the future
solar neutrino experiments are given, emphasizing the measurement of the energy
spectrum and the day-night effect in Sudbury Neutrino Observatory and
Super-Kamiokande to distinguish the two solutions.


title:
Nonperturbative Corrections to the Heavy Lepton Energy Distribution in
  the Inclusive Decays $H_b\ra \tau\bar\nu X.$

abstract:
  Nonperturbative corrections up to $m_b^{-2}$ to the heavy lepton energy
distributions are investigated in the inclusive semileptonic weak decays of
heavy flavors in QCD. In the case of $B$-meson decays, for $b \ra u\tau\bnu$
transitions they decrease the decay rate by 6\% of its perturbative value,
while for $b \ra c\tau\bnu$ they decrease it by 10\%.


title: Nonperturbative Effects in QCD at $T>0$

abstract:
  The background field formalism is used to implement nonperturbative QCD
contributions into diagrammatic technic at $T>0$. The leading terms both in the
confining and nonconfining phase are identified at large $N_c$ and the
transition temperature is calculated in this limit, which appears to be in good
agreement with the Monte Carlo calculations.


title: Ideas in Nonperturbative QCD

abstract:
  The structure of the hadron spectrum is discussed in connection with the main
phenomena of nonperturbative QCD: confinement and chiral symmetry breaking
(CSB). For the higher part of the spectrum ($M \ge 2 GeV$) spin and chiral
effects are unimportant; spectrum of $q\bar{q}$ system is described by an
effective Hamiltonian deduced from QCD. The Hamiltonian reduces to relativistic
quark potential model or to the open string model in two opposite limits.
Hybrids are shown to appear naturally in theory and enter the multiplets which
are compared to experiment and bosonic string theory. The phenomenon of
conspiracy of the spectrum of radial excited states producing operator product
expansion is discussed. The lower part of the spectrum $(M< 2 GeV)$ is
influenced by spin and chiral effects. CSB and the chiral quark mass are
deduced for the vacuum containing instantons and confining background. Main
points are summarized in conclusion.


title:
Marching towards a Theory of Non-leptonic Decays of heavy-Flavour
  Hadrons"

abstract:
  Theoretical descriptions for the nonleptonic decays of heavy flavour hadrons
have emerged that incorporate non-perturbative corrections in a systematic way
and are genuinely based on QCD. One can reproduce $\tau (D^+)/\tau (D^0)$,
$BR_{SL}(D^+)$ and $BR_{SL}(D^0)$ as due mainly to destructive interference in
$D^+$ decays; one predicts $\tau (B^-)$ to exceed $\tau (B_d)$ by a few per
cent; $BR_{SL}(B)$ is reduced only slightly, raising the prospects of a serious
and tantalizing conflict with ARGUS \& CLEO data. It is emphasized that the
lifetimes for the two mass eigenstates in the $B_s$-$\bar B_s$ system could
differ by 30\% or even more. The status of phenomenological treatments of
non-leptonic two-body modes is briefly reviewed.


title: Fermions, Anomaly and Unitarity in High-Energy Electroweak Scattering

abstract:
  We report the "state of the art" of the problem of $B+L$ violation in
high-energy electroweak scatterings. Results of various analyses point toward
(though do not prove rigorously yet) the "half-suppression", i.e., that the
$B+L$ violating cross section remains suppressed at least by the negative
exponent of the single instanton action, at all energies. Most interesting
techniques developed in this field are reviewed. Particular attention is paid
to unitarity constraints on the anomalous cross section, and to some conceptual
problem involving the use of the optical theorem in the presence of instantons.


title: Advantages in Choosing Real Generators for SU(N)

abstract:
  Some results are presented indicating the distinct advantages that accrue
from choosing a real representation for the generators of SU(N) rather than the
usual and more popular Gell-Mann type matrices. A few examples in the context
of quantum chromodynamics are used to serve as illustrations.


title: Experimental and Astrophysical Status of Neutrino Masses

abstract:
  The experimental and astrophysical status of neutrino masses is reviewed with
an emphasis on the cosmologically interesting regime.


title:
Radiative Electroweak Symmetry Breaking and the Infrared Fixed Point of
  the Top Quark Mass

abstract:
  The infrared quasi fixed point solution for the top quark mass in the Minimal
Supersymmetric Standard Model explains in a natural way large values of the top
quark mass and appears as a prediction in many interesting theoretical schemes.
Moreover, as has been recently pointed out, for moderate values of $\tan\beta$,
in order to achieve gauge and bottom-tau Yukawa coupling unification, the top
quark mass must be within $10 \%$ of its fixed point value. In this work we
show that the convergence of the top quark mass to its fixed point value has
relevant consequences for the (assumed) universal soft supersymmetry breaking
parameters at the grand unification scale. In particular, we show that the low
energy parameters do not depend on $A_0$ and $B_0$ but on the combination
$\delta = B_0 - A_0/2$. Hence, there is a reduction in the number of
independent parameters. Most interesting, the radiative $SU(2)_L \times U(1)_Y$
breaking condition implies strong correlations between the supersymmetric mass
parameter $\mu$ and the supersymmetry breaking parameters $\delta$ and
$M_{1/2}$ or $m_0$. These correlations, which become stronger for $\tan\beta <
2$, may have some fundamental origin, which would imply the need of a
reformulation of the naive fine tuning criteria.


title: Unstable Particles and Gauge Invariance

abstract:
  When computing the properties of reactions involving unstable charged
particles care has to be taken to use a gauge invariant amplitude. In this talk
we present methods to (automatically) obtain such an amplitude, both at the
tree level and in one-loop calculations, using only a minimal number of
diagrams. The numerical difference with gauge variant methods commonly used
will be discussed for the case of tree level W pair production.


title: Why the real time formalism doesn't factorise

abstract:
  We show that in the real time formalism, the generating functional for
thermal Green functions does not factorise. However for most calculations, the
normal real time Feynman rules can still be used to give correct results.


title: Zeroing In On the Top Quark, LSP and Scalar Higgs Masses

abstract:
  We estimate the top quark, lightest sparticle (LSP) and scalar higgs masses
within a supersymmetric grand unified framework in which $\tan\beta \simeq
m_t/m_b$ and the electroweak symmetry is radiatively broken. The requirement
that the calculated $b$ quark mass lie close to its measured value, together
with the cosmological constraint $\Omega_{LSP} \approx 1$, fixes the top quark
mass to be $m_t(m_t) \approx 170 \pm 15\ GeV$. The LSP (of bino purity
$\stackrel{_>}{_\sim} 98\%)$ has mass $\sim 200 - 350\ GeV$. In the scalar
higgs sector the CP-odd scalar mass $m_A \stackrel{_<}{_\sim} 220\ GeV$. With
$m_A \stackrel{_>}{_\sim} M_Z$, as suggested by the decay $b \rightarrow
s\gamma$, we find $M_Z \stackrel{_<}{_\sim} m_{h^0} (m_{H^0})
\stackrel{_<}{_\sim} 140 (220)\ GeV$ and $120\ GeV \stackrel{_<}{_\sim}
m_{H^\pm} \stackrel{_<}{_\sim} 240\ GeV$.


title: Report of the Subgroup on the Top Quark

abstract:
  The top group studied discovery issues as well as measurements to be made at
the Tevatron, the LHC and the SSC.


title:
New Approach for the Construction of Fermion Mass Matrices in SO(10)
  SUSY GUTS

abstract:
  A new procedure is developed which enables one to start from the quark and
lepton mass and mixing data at the low scale and construct mass matrices which
exhibit simple SO(10) structure at the SUSY GUT scale. This approach is applied
to the present data involving quark and charged lepton masses, the CKM mixing
matrix and the MSW solar neutrino and atmospheric neutrino depletion effects.
In terms of just 12 model parameters suggested by the procedure for the 5 mass
matrices, we can reproduce 15 masses and 8 mixing parameters remarkably
consistent with the input starting values.


title:
The b -> s gamma decay in supergravity with radiatively electroweak
  breaking

abstract:
  It is analyzed the branching ratio $B(b\rightarrow s\gamma)$ in the context
of minimal $N=1$ supergravity with radiatively broken electroweak symmetry
group. There is a strong dependence on supersymetric parameters, but
constraints on the charged Higgs mass in non-supersymmetric models are relaxed,
due to large contribution from the chargino/up-type squark sector that
interacts destructively with the Standard Model and the charged Higgs
contributions. Large suppressions/enhancements of the branching fraction are
found for large values of $\tan\beta$.


title:
Effective action of magnetic monopole in three-dimensional
  electrodynamics with massless matter and gauge theories of superconductivity

abstract:
  We compute one-loop effective action of magnetic monopole in
three-dimensional electrodynamics of massless bosons and fermions and find that
it contains an infrared logarithm. So, when the number of massless matter
species is sufficiently large, monopoles are suppressed and in the weak
coupling limit charged particles are unconfined. This result provides some
support to gauge theories of high-temperature superconductors. It also provides
a mechanism by which interlayer tunneling of excitations with one unit of the
ordinary electric charge can be suppressed while that of a doubly charged
object is allowed.


title: Bounds for Bose-Einstein Correlation Functions

abstract:
  Bounds for the correlation functions of identical bosons are discussed for
the general case of a Gaussian density matrix. In particular, for a purely
chaotic system the two-particle correlation function must always be greater
than one. On the other hand, in the presence of a coherent component the
correlation function may take values below unity. The experimental situation is
briefly discussed.


title: Implications of a Light Gluino

abstract:
  We show that the possibility of having light gluinos is not in conflict with
recent LEP measurements and also that cosmology does not rule it out in any
convincing way. In unified N=1 supergravity models, one expects that also the
"photino" will be light. Moreover it leads to $upper$ limits on the masses of
the other supersymmetric fermions, for example, the lightest chargino should be
lighter than about 75 GeV, an thus detectable at LEP200.


title: A Virial Theorem for the Kinetic Energy of a Heavy Quark inside Hadrons

abstract:
  The formalism of the heavy quark effective theory is used to derive the
field-theory analog of the virial theorem, which relates the matrix element of
the kinetic energy of a heavy quark inside a hadron to a matrix element of the
gluon field strength tensor. The existing QCD sum rule calculations of the
kinetic energy are not consistent with this theorem.


title:
Introduction to $Z_N$ Symmetry in $SU_N$ Gauge Theories at Finite
  Temperatures

abstract:
  There have been several talks at this workshop on the physical interpretation
and consequences of the $Z_N$ symmetry which is present in the Euclidean Path
Integral formulation of $SU_N$ Gauge Theories at finite temperature. The
purpose of this paper is to present an introduction to this subject. After a
brief review of Gluodynamics at finite temperature, the nature of the $Z_N$
symmetry in this system is described and its relationship to confinement is
discussed. $Z_N$ domain walls and bubbles are then described as is their
relationship to the confining--deconfining phase transition. The effect of
Fermions is then considered and the presence of metastable extrema of the
Effective Potential for the Polyakov--Wilson Line is described. It is then
argued that these metastable extrema do not correspond to physically realizable
metastable states.


title: Baryon decuplet mass relations in chiral perturbation theory

abstract:
  Baryon decuplet masses within an $SU(3)_L \times SU(3)_R$ chiral Lagrangian
formalism are found to satisfy four relations at second order in flavor
breaking. As a result, the one-loop corrections from Lagrangian terms up to
first order in flavor breaking are observed to give finite and calculable
corrections to these relations. The formal expressions for these corrections
are presented, followed by numerical evaluations. We find consistency between
the experimental values of breaking of the relations and the loop corrections
of these relations as predicted by chiral perturbation theory.


title: Comment on the Average Momentum of Top Quarks in the Threshold Region

abstract:
  The behavior of the momentum distribution of top quarks in the threshold
region is investigated. The qualitative behavior, in particular the dependence
of the average momentum on the strong coupling constant can be understood from
analytical calculations for the Coulomb potential. Ambiguities in the relation
between the excitation curve and the top mass are addressed.


title: Soft Fields and Hard Particles in Hot Gauge Plasmas

abstract:
  It is shown that the long wavelength excitations of a quark-gluon plasma may
be described as collective oscillations of self-consistent average fields to
which the plasma particles couple. Their properties are obtained from a set of
coupled mean field and kinetic equations, derived from the general
Dyson-Schwinger equations, as the leading order in a systematic expansion in
powers of the coupling. By solving the kinetic equations, one obtains in closed
form the generating functionals for all the leading order amplitudes between
soft quasiparticles, the so-called ``hard thermal loops''.


title:
Decisive test of color transparency in exclusive electroproduction of
  vector mesons

abstract:
  The exclusive production of vector mesons in deep inelastic scattering is a
hard scattering process with the well controlled size of quark configurations
which dominate the production amplitude. This allows an unambiguous prediction
of color transparency effects in the coherent and incoherent production of
vector mesons on nuclei. We demonstrate how the very mechanism of color
transparency leads to a belated onset of color transparency effects as a
function of $Q^{2}$. We conclude that the $Q^{2}$ dependence of the exclusive
$\rho^{0}$-meson production on nuclei and nucleons observed in the Fermilab
E665 experiment gives a solid evidence for the onset of color transparency. We
propose the scaling relation between the $\rho^{0}$ and the $J/\Psi$
production, which further tests the mechanism of color transparency in
exclusive (virtual) photoproduction.


title: Color Transparency after the Ne18 and E665 Experiments

abstract:
  The 1993 witnessed two major news in the field of color transparency (CT): i)
no effect of CT was seen in the SLAC NE18 experiment on $A(e,e'p)$ scattering
at virtualities of the exchanged photon $Q^{2} \lsim 7$ GeV$^{2}$, ii) strong
signal of CT was observed in the Fermilab E665 experiment on exclusive
$\rho^{0}$-meson production in deep inelastic scattering in the same range of
$Q^{2}$. Both are good news and rule in CT, since this striking difference in
the onset of CT for two reactions was predicted theoretically, and we review
the theory of both reactions and the origin of this difference. We discuss an
importance of final state interaction effects for the theoretical
interpretation of the NE18 data. We comment on possible CT effects in the
$^{4}He(e,e'p)$ interactions at CEBAF.


title: B + L Non-Conservation as a Semi-Classical Process

abstract:
  I discuss the problem of computing B + L violation at high energies as that
of solving classical differential equations. These equations involve boundary
conditions at initial and a final times which are anti-Feynman, and involve
solving non-linear differential equations which are complex, even if the
original Hamiltonian was real.


title: Thermal Self-Energies Near Zero Four-Momentum

abstract:
  (Talk presented at the 3rd Workshop on Thermal Field Theories and Their
Applications, Banff, Canada, August 1993. This is a review of work done with
Peter Arnold, Paulo Bedaque, and Ashok Das.) We demonstrate that one-loop
self-energies at finite temperature have a unique limit as the external
four-momentum goes to zero, as long as the particles propagating in the loop
have distinct masses. We show that in spontaneously broken theories, this
result nonetheless does not affect the difference between screening and
propagating modes and hence the usual resummed perturbation expansion remains
unaltered.


title: A Layman's guide to SUSY GUTs

abstract:
  The determination of the most straightforward evidence for the existence of
the Superworld requires a guide for non-experts (especially experimental
physicists) for them to make their own judgement on the value of such
predictions. For this purpose we review the most basic results of Super-Grand
unification in a simple and clear way. We focus the attention on two specific
models and their predictions. These two models represent an example of a direct
comparison between a traditional unified-theory and a string-inspired approach
to the solution of the many open problems of the Standard Model. We emphasize
that viable models must satisfy {\em all} available experimental constraints
and be as simple as theoretically possible. The two well defined supergravity
models, $SU(5)$ and $SU(5)\times U(1)$, can be described in terms of only a few
parameters (five and three respectively) instead of the more than twenty needed
in the MSSM model, \ie, the Minimal Supersymmetric extension of the Standard
Model. A case of special interest is the strict no-scale $SU(5)\times U(1)$
supergravity where all predictions depend on only one parameter (plus the
top-quark mass). A general consequence of these analyses is that supersymmetric
particles can be at the verge of discovery, lurking around the corner at
present and near future facilities. This review should help anyone distinguish
between well motivated predictions and predictions based on arbitrary choices
of parameters in undefined models.


title: Status of Lattice QCD

abstract:
  Significant progress has recently been achieved in the lattice gauge theory
calculations required for extracting the fundamental parameters of the standard
model from experiment. Recent lattice determinations of such quantities as the
kaon $B$ parameter, the mass of the $b$ quark, and the strong coupling constant
have produced results and uncertainties as good or better than the best
conventional determinations. Many other calculations crucial to extracting the
fundamental parameters of the standard model from experimental data are
undergoing very active development. I review the status of such applications of
lattice QCD to standard model phenomenology, and discuss the prospects for the
near future.


title: $D_s$ Lifetime, $m_b$, $m_c$ and $|V_{cb}|$ in the Heavy Quark Expansion

abstract:
  We present some straightforward applications of the QCD heavy quark
expansion, stated in previous papers [1-3], to the inclusive widths of heavy
flavour hadrons. We address the question of the $D_s$ lifetime and argue that
-- barring Weak Annihilation (WA) -- $\tau (D_s)$ is expected to exceed $\tau
(D^0)$ by several percent; on the other hand WA could provide a difference of
up to $10\div20\%$ of {\it any} sign. We extract $m_c$, $m_b$ and $|V_{cb}|$
from $\Gamma\ind{SL}(D^+)$ and $\Gamma\ind{SL}(B)$. The values of the quark
masses are somewhat higher, but compatible with estimates from QCD sum rules;
we obtain $|V_{cb}|\simeq 0.043$ for $\tau (B)=1.4$ psec and
$BR_{SL}(B)=10.5$\% . We discuss the associated uncertainties in the $1/m_Q$
expansion as well as some consequences for other electroweak decays.


title: Qualitons from QCD

abstract:
  Qualitons, topological excitations with the quantum numbers of quarks, may
provide an accurate description of what is meant by constituent quarks in QCD.
Their existence hinges crucially on an effective Lagrangian description of QCD
in which a pseudoscalar colour-octet of fields enters as a new variable. We
show here how such new fields may be extracted from the fundamental QCD
Lagrangian using the gauge-symmetric collective field technique.


title: Cancellation of Infrared Divergences in QED at Nonzero Temperature

abstract:
  The radiation produced by a classical charged current coupled to a quantized
$A_{\mu}$ is first computed. To each order in $\alpha$, all infrared
divergences cancel between the virtual $\gamma$'s and the real $\gamma$'s that
are absorbed from or emitted into the plasma. When all orders of perturbation
theory are summed, the finite answer predicts a suppression of radiation with
$\omega< \alpha T$. The analysis of QED then consists of two steps. First, a
general probability at $T\neq 0$ is organized so that all the virtual
$e^{\pm},\gamma$ are in the amplitudes and all the real $e^{\pm},\gamma$ are in
the phase space integrations. Next, the cancellations of IR divergences between
virtual and real are demonstrated.


title: Dibaryons as axially symmetric skyrmions

abstract:
  Dibaryons configurations are studied in the framework of the bound state
soliton model. A generalized axially symmetric ansatz is used to determine the
soliton background. We show that once the constraints imposed by the symmetries
of the lowest energy torus configuration are satisfied all spurious states are
removed from the dibaryon spectrum. In particular, we show that the lowest
allowed state in the $S=-2$ channel carries the quantum numbers of the H
particle. We find that, within our approximations, this particle is slightly
bound in the model. We discuss, however, that vacuum effects neglected in the
present calculation are very likely to unbind the H.


title: Perturbation theory in the nonperturbative QCD vacuum

abstract:
  Perturbative expansion in the nonperturbative confining QCD background is
formulated. The properly renormalized $\alpha_S(R)$ is shown to be finite at
large distances, with the string tension playing the role of an infrared
regulator. The infra--red renormalons are shown to be absent in the new
perturbation series.


title: Detecting Sleptons at Hadron Colliders and Supercolliders

abstract:
  We study the prospects for detecting the sleptons of the Minimal
Supersymmetric Standard Model at hadron colliders and supercolliders. We use
ISAJET 7.03 to simulate charged slepton and sneutrino pair production,
incorporating slepton and sneutrino cascade decays into our analysis. We find
that even with an accumulation of $\sim 1$fb$^{-1}$ of integrated luminosity,
it will be very difficult to detect sleptons beyond the reach of LEP at the
Fermilab Tevatron $p\bar{p}$ collider, due to a large background from $W$ pair
production. At LHC, sleptons of mass up to 300 GeV ought to be detectable via
dilepton signal as long as it is possible to veto central jets with $p_T \geq
25$ GeV with high efficiency.


title: Moderate Supersymmetric CP Violation

abstract:
  It is well known that supersymmetry (SUSY) gives neutron and electron
electric dipole moments ($d_n$ and $d_e$) which are too large by about
$10^{3}$. If we assume a SUSY model cannot contain fine-tunings or large mass
scales, then one must require that the SUSY breaking mechanism give real soft
breaking parameters, in which case the minimal SUSY model has no $CP$ violation
other than from the CKM matrix (besides possible strong $CP$ violating
effects). We show that in non-minimal SUSY models, a moderate amount of $CP$
violation can be induced through one loop corrections to the scalar potential,
giving an effective phase of order $10^{-3}$, and thus implying $d_n$ and $d_e$
can be near their current experimental bounds $naturally$. This moderate amount
of SUSY $CP$ violation could also prove important for models of electroweak
baryogenesis. We illustrate our results with a specific model.


title: Quark Solitons from Effective Action of QCD

abstract:
  We derive an effective low energy action for QCD in 4 dimensions. The low
energy dynamics is described by chiral fields transforming non-trivially under
both color and flavor. We use the method of anomaly integration from the QCD
action. The solitons of the theory have the quantum numbers of quarks. They are
expected to be the constituent quarks of hadrons. In two dimensions our result
is exact, namely the bosonic gauged action of WZW.


title: Yukawa Coupling Evolution In SUSY GUTS

abstract:
  The scaling behavior and fixed points in the evolution of fermion Yukawa
couplings and mixing angles are discussed. The relevance of fixed points in
determining the top quark mass is described.


title: RGE Results for Supersymmetric GUTS

abstract:
  The scaling behavior of gauge couplings and fermion Yukawa couplings in the
minimal supersymmetric model is discussed. The relevance of the top quark
Yukawa coupling fixed point in establishing the top quark mass is described.
The evolution of mixing angles is presented.


title: Theory Summary and Future Directions

abstract:
  Summary talk at the Lepton-Photon Symposium, Cornell University, Aug. 10-15,
1993.


title: Isoscalar-isovector mass splittings in excited mesons

abstract:
  Mass splittings between the isovector and isoscalar members of meson nonets
arise in part from hadronic loop diagrams which violate the Okubo-Zweig-Iizuka
rule.
  Using a model for these loop processes which works qualitatively well in the
established nonets, I tabulate predictions for the splittings and associated
isoscalar mixing angles in the remaining nonets below about 2.5 GeV, and
explain some of their systematic features.
  The results for excited vector mesons compare favorably with experiment.


title: On the Q^2 Dependence of Measured Polarized Structure Funtions

abstract:
  We analyse the available data on the polarized asymmetries $A_1$ for proton,
neutron and deuteron targets. We use a homogeneous and updated set of
unpolarized structure functions to derive $g_1$ from $A_1$, and we accurately
correct for the scaling violations in order to obtain $g_1(x,Q^2)$ with the
same $Q^2$ for all $x$ values. The contribution to the $Q^2$ evolution of a
possible large gluon polarized density is also considered. The implications for
the Ellis-Jaffe and for the Bjorken sum rules are discussed.


title:
Rare $B$-Decays and Heavy to Light Semileptonic Transitions in the Isgur
  and Wise Limit

abstract:
  From the experimental branching ratios for $B^- --> \rho^0 l^-\bar\nu_l$ and
$D^+ --> {\overl K}^{*0}({\overl K}^0) e^+ \nu_e$ one finds, in the Heavy Quark
Limit of $HQET$, $ |V_{bu}|=(8.1\pm 1.7) x 10^{-3}$, larger but consistent with
the actual quoted range $(2 - 7) x 10^{-3}$. In the same framework one predicts
for $R(B --> K^*\gamma)=( 2 \pm 2 ) 10^{-2}$.


title:
Probing Lepton Number Violation via Majorana Neutrinos at Hadron
  Supercolliders

abstract:
  The possibility of discovering heavy Majorana neutrinos and lepton number
violation via the like sign dilepton signal at hadron super- colliders is
investigated. The cross-sections for the production of these neutrinos singly
as well as in pairs are computed both in three and four generation scenarios
within the framework of the gauge group $SU(2)_L \otimes U(1)_Y$ and the
dominant processes are identified. The suppression of the Standard model
background by suitable kinematical cuts is also discussed.


title: CP Violation in Higgs Decays due to Majorana Neutrinos

abstract:
  The possibility of observing CP violation in the decays of Higgs particles
into top-quark, W- and Z-boson pairs induced by heavy Majorana neutrinos is
discussed. In the context of minimal "see-saw" models with interfamily mixings,
we find that Majorana neutrinos may give rise to sizable CP-odd effects at the
one-loop electroweak order. We present numerical estimates of typical CP-odd
observables that might be triggered at high-energy e+e- colliders.


title: Equivalence of Hamiltonian and Lagrangian Path Integral Quantization

abstract:
  The HLE theorem is proven for effective Lagrangians with arbitrary
interactions of scalars, fermions, massless and massive vector bosons. This
theorem states that the correct Hamiltonian path intergral formalism is
equivalent to the convenient Lagrangian path integral ansatz. In particular,
this theorem is valid for effective gauge theories, which justifies
Faddeev-Popov quantization of these theories. Specific attention is paid to
effective interactions of massive vector fields, which can be embedded within
gauge noninvariant theories or within spontaneously broken gauge theories.
These different types of models are related to each other by the Stuckelberg
formalism, which is reformulated within the Hamiltonian formalism. Effective
Lagrangians with higher derivatives of the fields are also considered. The HLE
theorem is even valid in this case because each effective higher-order
Lagrangian can be reduced to a first-order one by applying the equations of
motion to the effective interaction term. This thesis is essentially a
combination of previous publications of the author.


title: Large $\pt$ Hadroproduction of Heavy Quarks

abstract:
  The production of heavy quarks at large $\pt$ ($\pt\gg m$) in hadronic
collisions is considered. The analysis is carried out in the framework of
perturbative fragmentation functions, thereby allowing a resummation at the NLO
level of final state large mass logarithms of the kind $\log(\pt/m)$. The case
of $b$-quark production is considered in detail. The resulting theoretical
uncertainty from factorization/renormalization scales at large $\pt$ is found
to be much smaller than that shown by the full $O(\as^3)$ perturbative
calculation.


title: Testing the Higgs system at a photon-photon collider

abstract:
  The level of sensitivity of the processes $\gamma\gamma \to ZZ$,
$\gamma\gamma \to W^+W^-$ and $\gamma\gamma \to t\bar t$ to the Higgs sector of
the Standard Model Lagrangian in the energy region between 200 GeV and 1 TeV is
examined. The elementary Higgs boson is taken to have a mass less than 1 TeV.
Sizeable effects are found in the $ZZ$ and $t\bar t$ channels if the incoming
photons have the same helicity. Also the possibility that the elementary Higgs
boson does not exist is examined. Assuming new physics to show up in the TeV
energy region the cross sections are evaluated according to the heavy Higgs
model. For center of mass energy values close to 1 TeV interesting effects are
found in the $t\bar t$ channel if the photons have the same helicity. The limit
of large Higgs mass is not unique. The parametrization of this arbitrariness
may be interpreted as a representation of the new physics. The effects for the
processes $\gamma\gamma\to ZZ$ and $\gamma\gamma\to t\bar t$ are investigated.
These effects may be correlated to a possible resonance in $WW$ scattering in
the TeV region.


title: The Total and Jet Photoproduction Cross Sections at HERA and Fermilab

abstract:
  We present results of calculations of the total and jet photoproduction cross
sections at HERA and Fermilab energies$^1$. The calculations take into account
the high-energy QCD structure of the photon and are performed for different
photon structure functions. We discuss how recent measurements of the total
photoproduction cross section at HERA energies$^2$ can provide an important
information on the low $x$ behavior of the photon structure function and in a
more general context, to the nature of strong interactions. In addition, we
show that the photoproduction cross section measurements at Fermilab E683
energies could provide a firmer value for $p_{T}^{min}$, the lower bound on the
transverse momentum of outgoing jets, which signals the onset of hard
scattering. The extrapolation of our cross section to ultra-high energies, of
relevance to the cosmic ray physics, gives significant contribution to the
``conventional'' value, but cannot account for the anomalous muon content
observed in the cosmic ray air-showers associated with astrophysical point
sources$^4$.


title: Single Top Production at the Next Generation Linear e+e- Colliders

abstract:
  Present limits on the top mass from LEP1 and Tevatron point to a top quark
that is considerably heavier than the $W$ vector boson in the standard model.
Hence, e+e- colliders with \sqrt{s} \simeq 300 GeV (the c.m. energy foreseen at
the first phase of the Next Linear e+e- Collider) could be well below the
energy threshold for real top-pair production. We argue that, if this is the
case, single top production through the process e+e- --> t\bar{b}W-
(\bar{t}bW+), where t\bar{b} (\bar{t}b) are produced mainly by means of a
virtual W, becomes the dominant top production mechanism. Total cross sections
and kinematical distributions are evaluated and numerical results are given in
ranges of m_t and \sqrts{s} where single top production can be of relevance.
The relative importance of virtual-W and virtual-t contributions to the process
is discussed.


title: Nonrelativistic effective Lagrangians

abstract:
  Chiral perturbation theory is extended to nonrelativistic systems with
spontaneously broken symmetry. In the effective Lagrangian, order parameters
associated with the generators of the group manifest themselves as effective
coupling constants of a topological term, which is gauge invariant only up to a
total derivative. In the case of the ferromagnet, a term connected with the
Brouwer degree dominates the derivative expansion. The general analysis
includes antiferromagnetic magnons and phonons, while the effective field
theory of fluids or gases is beyond the scope of the method.


title: Model Dependence of $W_R$ Searches at the Tevatron

abstract:
  We explore the sensitivity of the on-going Tevatron search for charged,
right-handed gauge bosons, $W_R^{\pm}$, to various model dependent assumptions
such as the magnitude of the $SU(2)_R$ gauge coupling, the values of the
right-handed Kobayashi-Maskawa mixing matrix elements, $(V_R)_{ij}$, and the
nature of the right-handed neutrino. These results also have important
implications for HERA searches for right-handed currents.


title:
Heavy diquark in baryons containing a single heavy quark and the weak
  form factors

abstract:
  It is shown that the number of independent weak form factors collapses if the
heavy diquark exists inside the baryons containing a single heavy quark. The
relations between the weak form factors are quite different in the case of
light diquark. So a careful analysis on the future data of the weak form
factors would clarify that in those baryons the correlation between the heavy
quark and a light quark is stronger or weaker than the one between two light
quarks.


title:
Longevity of the quark-gluon plasma and the mixed phase from intensity
  interferometry of high energy photons

abstract:
  Two-photon intensity interferometry is shown to provide an accurate
measurement of lifetime of quark-gluon plasma created in ultra-relativistic
heavy ion collisions via the difference of outward and sidewardcorrelation
radii. Under the assumption of a longitudinal, boost invariant expansion of the
plasma, we obtain analytical expressions for the correlations from the
quark-gluon plasma phase. A $3+1$ dimensional expansion of the plasma along
with a first order phase transition to hadrons is next considered, and, leads
to a source with two characteristic lifetimes, one for the quark-gluon plasma
phase, and the other for the longer lived mixed phase. This may even help us to
{\em experimentally} determine the order of the phase transition.


title:
An upper bound on $P$-wave charmonium production via the color-octet
  mechanism

abstract:
  A factorization theorem for $P$-wave quarkonium production, recently derived
by Bodwin, Braaten, Yuan and Lepage, is applied to $\Upsilon \to \chi_{cJ} +
X$, where $\chi_{cJ}$ labels the ${}^3 P_J$ charmonium states. The widths for
$\chi_{cJ}$ production through color-singlet $P$-wave and color-octet $S$-wave
$c \bar c$ subprocesses are computed each to leading order in $\alpha_s$.
Experimental data on $\Upsilon \to J / \psi + X$ is used to obtain an upper
bound on a nonperturbative parameter (related to the probability for
color-octet $S$-wave $c \bar c$ hadronization into $P$-wave charmonium) that
enters into the factorization theorem.


title: The Supersymmetric Particle Spectrum

abstract:
  We examine the spectrum of supersymmetric particles predicted by grand
unified theoretical (GUT) models where the electroweak symmetry breaking is
accomplished radiatively. We evolve the soft supersymmetry breaking parameters
according to the renormalization group equations (RGE). The minimization of the
Higgs potential is conveniently described by means of tadpole diagrams. We
present complete one-loop expressions for these minimization conditions,
including contributions from the matter and the gauge sectors. We concentrate
on the low $\tan \beta$ fixed point region (that provides a natural explanation
of a large top quark mass) for which we find solutions to the RGE satisfying
both experimental bounds and fine-tuning criteria. We also find that the
constraint from the consideration of the lightest supersymmetric particle as
the dark matter of the universe is accommodated in much of parameter space
where the lightest neutralino is predominantly gaugino. The supersymmetric mass
spectrum displays correlations that are model-independent over much of the GUT
parameter space.


title: SU(3)--Breaking Effects in Axial--Vector Couplings of Octet Baryons

abstract:
  Present evidence on baryon axial--vector couplings is reviewed, the main
emphasis being on internal consistency between asymmetry and rate data. A
complete account of all {\sl small} terms in the Standard Model description of
these latter leads to {\sl both} consistency {\sl and} evidence for breaking of
flavour SU(3) in the axial couplings of octet baryons.
  Talk presented at "5th Int. Sympos. on Meson--Nucleon Physics and the
Structure of the Nucleon", Boulder, CO, sept. 1993. To be published in $\pi N$
Newsletter.


title: Spontaneous CP-Violation in the Extended Standard Models

abstract:
  The spontaneous CP-violation in three kinds of extension of the standard
model are investigated. We find that if no additional symmetry is introduced to
reduce the number of coefficients, then all three extended models possess the
spontaneous CP violation (SCPV) in the Higgs potential. When symmetry under
which the doublets transform as $\Phi_1 \to \Phi_1$ and $\Phi_2 \to
e^{i\gamma}\Phi_2$ is introduced, the two-Higgs doublet model will lose its
SCPV terms. In the other two extended models, the SCPV terms will be preserved
since both models contain at least one Higgs singlet which can appear in odd
powers. The extended model with two doublets and one singlet is reviewed and
the general conditions which make the CP-violating $V_{min}$ the true minimum
are given. The generally called natural flavour-conserving models are also
discussed briefly.


title:
Feynman Rules in the Type III Natural Flavour-Conserving Two-Higgs
  Doublet Model

abstract:
  We consider a two Higgs-doublet model with $S_3$ symmetry, which implies a
$\pi \over 2$ rather than 0 relative phase between the vacuum expectation
values $<\Phi_1>$ and $<\Phi_2>$. The corresponding Feynman rules are derived
accordingly and the transformation of the Higgs fields from the weak to the
mass eigenstates includes not only an angle rotation but also a phase
transformation. In this model, both doublets couple to the same type of
fermions and the flavour-changing neutral currents are naturally suppressed. We
also demonstrate that the Type III natural flavour-conserving model is valid at
tree-level even when an explicit $S_3$ symmetry breaking perturbation is
introduced to get a reasonable CKM matrix. In the special case $\beta =
\alpha$, as the ratio $\tan\beta = {v_2 \over v_1}$ runs from 0 to $\infty$,
the dominant Yukawa coupling will change from the first two generations to the
third generation. In the Feynman rules, we also find that the charged Higgs
currents are explicitly left-right asymmetric. The ratios between the left- and
right-handed currents for the quarks in the same generations are estimated.


title:
The Energies of All Hadrons(INCLUDING All Known Resonances) and the
  Energies of the Excited States of Quarks

abstract:
  By means of a general classification of the different kinds of matter which
were formed along the universal expansion, the paper shows that the force of
nature form a chain from the world of the prequarks to the galaxies. It is
shown that matter has a generalized structured state characterized by some
degree of order and by a Lennard-Jones effective potential. The existence of
this state at the level of quarks and galaxies suggests that nature has two
more fundamental forces, a superstrong interaction which acts among prequarks
and quarks, and a superweak interaction which acts among galaxies and clusters
of galaxies. Quark confinement is explained from first principles. The energies
of all hadrons, including all known resonances, are calculated in a simple
manner. The error, for each particle, between calculated and experimental
values, is below 5%, in general, and goes as low as 0.5% for some levels. The
energies of all the other hadrons(which have not been found experimentally) are
predicted. The energies of the excited states of quarks are calculated.
According to the work the Higgs boson does not exist, since the masses of
hadrons and quarks are generated by an effective potential which comes about
from the combination of the strong and superstrong interactions.


title: On the Foundations of Chiral Perturbation Theory

abstract:
  The properties of the effective field theory relevant for the low energy
structure generated by the Goldstone bosons of a spontaneously broken symmetry
are reexamined. It is shown that anomaly free, Lorentz invariant theories are
characterized by a gauge invariant effective Lagrangian, to all orders of the
low energy expansion. The paper includes a discussion of anomalies and
approximate symmetries, but does not cover nonrelativistic effective theories.


title: High $Q^2$ Probe of Nuclear Spectral Function and Color Transparency

abstract:
  Contrary to widespread opinion, color transparency (CT) brings essential
ambiguity to, rather than helps in, study of the nuclear spectral function in
quasielastic lepton scattering, $A(l,l'p)A'$, at high $Q^2$. Although the
nuclear attenuation vanishes, the final state interaction (FSI) of a small-size
ejectile wave packet, propagating through nuclear matter, remains. It manifests
itself in a substantial, but uncertain, longitudinal momentum transfer to the
nuclear medium. We predict a strong Fermi-momentum bias of the nuclear
transparency at high $Q^2$, which enters as a factor at the nuclear spectral
function, and makes uncertain the results of measuring the high-momentum tail
of Fermi distribution.


title:
Heavy diquark effective theory and supersymmetry of hadrons containing a
  single heavy quark

abstract:
  A new supersymmetry is proposed for hadrons containing a single heavy quark.
This supersymmetry is based on a new approximation to those hadrons, which we
would consider as a further step beyond the spectator light diquark model of
baryons. The heavy diquark effective theory is constructed by the techniques
introduced in a different context by Georgi and Wise$^1$ and by Carone$^2$.
This theory can be incorporated into a supersymmetric theory together with
Heavy Quark Effective Theory, and leads to a common universal Isgur-Wise
function for mesons and baryons./.


title: New Precision Electroweak Tests of SU(5) x U(1) Supergravity

abstract:
  We explore the one-loop electroweak radiative corrections in $SU(5)\times
U(1)$ supergravity via explicit calculation of vacuum-polarization and
vertex-correction contributions to the $\epsilon_1$ and $\epsilon_b$
parameters. Experimentally, these parameters are obtained from a global fit to
the set of observables $\Gamma_{l}, \Gamma_{b}, A^{l}_{FB}$, and $M_W/M_Z$. We
include $q^2$-dependent effects, which induce a large systematic negative shift
on $\epsilon_{1}$ for light chargino masses ($m_{\chi^\pm_1}\lsim70\GeV$). The
(non-oblique) supersymmetric vertex corrections to $\Zbb$, which define the
$\epsilon_b$ parameter, show a significant positive shift for light chargino
masses, which for $\tan\beta\approx2$ can be nearly compensated by a negative
shift from the charged Higgs contribution. We conclude that at the 90\%CL, for
$m_t\lsim160\GeV$ the present experimental values of $\epsilon_1$ and
$\epsilon_b$ do not constrain in any way $SU(5)\times U(1)$ supergravity in
both no-scale and dilaton scenarios. On the other hand, for $m_t\gsim160\GeV$
the constraints on the parameter space become increasingly stricter. We
demonstrate this trend with a study of the $m_t=170\GeV$ case, where only a
small region of parameter space, with $\tan\beta\gsim4$, remains allowed and
corresponds to light chargino masses ($m_{\chi^\pm_1}\lsim70\GeV$). Thus
$SU(5)\times U(1)$ supergravity combined with high-precision LEP data would
suggest the presence of light charginos if the top quark is not detected at the
Tevatron.


title: Microphysical Approach to Nonequilibrium Dynamics of Quantum Fields

abstract:
  We examine the nonequilibrium dynamics of a self-interacting $\lambda\phi^4$
scalar field theory. Using a real time formulation of finite temperature field
theory we derive, up to two loops and $O(\lambda^2)$, the effective equation of
motion describing the approach to equilibrium. We present a detailed analysis
of the approximations used in order to obtain a Langevin-like equation of
motion, in which the noise and dissipation terms associated with quantum
fluctuations obey a fluctuation-dissipation relation. We show that, in general,
the noise is colored (time-dependent) and multiplicative (couples nonlinearly
to the field), even though it is still Gaussian distributed. The noise becomes
white in the infinite temperature limit. We also address the effect of
couplings to other fields, which we assume play the r\^ole of the thermal bath,
in the effective equation of motion for $\phi$. In particular, we obtain the
fluctuation and noise terms due to a quadratic coupling to another scalar
field.


title: Hypercharge and the Cosmological Baryon Asymmetry

abstract:
  Stringent bounds on baryon and lepton number violating interactions have been
derived from the requirement that such interactions, together with electroweak
instantons, do not destroy a cosmological baryon asymmetry produced at an
extremely high temperature in the big bang. While these bounds apply in
specific models, we find that they are generically evaded. In particular, the
only requirement for a theory to avoid these bounds is that it contain charged
particles which, during a certain cosmological epoch, carry a non-zero
hypercharge asymmetry. Hypercharge neutrality of the universe then dictates
that the remaining particles must carry a compensating hypercharge density,
which is necessarily shared amongst them so as to give a baryon asymmetry.
Hence the generation of a hypercharge density in a sector of the theory forces
the universe to have a baryon asymmetry.


title: Transverse Quark Distribution in Mesons - QCD Sum Rule Approach -

abstract:
  QCD sum rules are used to compute the first few moments of the mesonic quark
momentum. Transverse, longitudinal and mixed transverse-longitudinal components
are examined. The transverse size of the pion is shown to be dictated by the
gluon condensate, even though the mass and the longitudinal distribution are
dominated by the quark condensate. The implications of our results for color
transparency physics and finite temperature QCD are discussed.


title: Flavor Unification and Discrete Nonabelian Symmetries

abstract:
  Grand unified theories with fermions transforming as irreducible
representations of a discrete nonabelian flavor symmetry can lead to realistic
fermion masses, without requiring very small fundamental parameters. We
construct a specific example of a supersymmetric GUT based on the flavor
symmetry $\Delta(75)$ --- a subgroup of $SU(3)$ --- which can explain the
observed quark and lepton masses and mixing angles. The model predicts
$\tan\beta \simeq 2-5$ and gives a $\tau$ neutrino mass $m_\nu\simeq M_p/G_F
M_{GUT}^2 = 10$ eV, with other neutrino masses much lighter. Combined
constraints of light quark masses and perturbative unification place flavor
symmetry breaking near the GUT scale; it may be possible to probe these
extremely high energies by continuing the search for flavor changing neutral
currents.


title: Top Condensation without Fine-Tuning

abstract:
  Quadratic divergencies which lead to the usual fine-tuning or hierarchy
problem are discussed in top condensation models. As in the Standard Model a
cancellation of quadratic divergencies is not possible without the boson
contributions in the radiative corrections which are absent in lowest order of
an $1/N_c$-expansion. To deal with the cancellation of quadratic divergencies
we propose therefore an expansion in the flavor degrees of freedom. In leading
order we find the remarkable result that quadratic divergencies automatically
disappear.


title: Soft Physics and Intermittency: Open Question(s) in Krakow

abstract:
  This contribution contains a summary of the Krakow meeting on Soft Physics
and Fluctuations. It emphasizes both the experimental and the theoretical
investigations on correlations/fluctuations and intermittency in multi-particle
processes and discusses of the present status of this concept. A clarification
of the main open questions in this field of research is now within reach,
thanks to the studies presented at the meeting. Summary Talk of the Krakow
Workshop on Multiparticle Physics, May, 4-7, 1993. E-mail contact:
pesch@amoco.saclay.cea.fr


title: Gauge invariant top quark form factors from e+ e- experiments

abstract:
  Motivated by the possibility of experimental determination of top quark form
factors in upcoming e+ e- experiments, as recently discussed by Atwood and
Soni, we show at the one loop level that the conventionally defined magnetic
dipole moment (MDM) form factor of the top quark is gauge dependent, in the
class of renormalizable ($R_{\xi}$) gauges. We explicitly calculate its gauge
dependence, which, due to the massiveness of the top quark, turns out to be
numerically very sizable. We show how to use the S-matrix pinch technique in
order to define gauge independent form factors. The real and imaginary parts of
the gauge independent MDM form factor are calculated and their dependence on
the top quark and Higgs boson masses is discussed. Most noticeably, the
dependence on the Higgs mass turns out to be stronger than that of the cross
section as a whole.


title: OPE analysis for polarized deep inelastic scattering

abstract:
  We present an explicit OPE analysis for the first moment of $g_1$ up to order
$M^2/Q^2$. This result allows to calculate power corrections to the Bjorken and
Ellis--Jaffe sum rules.


title: Lepton Masses Protect the Primordial Baryogenesis from Spaleron erasure

abstract:
  This talk is based on work performed with Graham Ross and is a very concise
summary of our soon to be published paper. Here we present a revision of the
analysis of sphaleron baryon-number violating processes in the standard model
including lepton-mass effects. We find the surprising result that a GUT-scale
matter-asymmetry can survive the $B$ and $L$ violating sphaleron interactions
even though ($B- L$) is conserved and equals zero for all temperatures. We
extend the analysis to cover the minimal supersymmetric standard model (MSSM).
As a new result we present the MSSM analysis below the temperature of
electroweak breaking and for $B-L=0$ at all temperatures


title:
1/m_c Expansion of Omega_b -> Omega_c^(*) Semileptonic Decay Form
  Factors

abstract:
  A simple model of Omega_Q and Omega_Q^(*) baryons containing one heavy quark
Q is constructed. Amplitudes are represented by loop graphs with one line for
the heavy quark and another for the light degrees of freedom. The latter are
modelled as a freely-propagating vector particle interacting nonlocally with
the heavy baryon and a free heavy quark. It is argued that the physics of
confinement plays an inessential role in determining semileptonic decay form
factors. The model has a well-defined heavy-quark expansion which has a form
consistent (through order 1/m_Q) with that determined by QCD through the
heavy-quark effective theory. The slope of the Isgur-Wise function is
consistent with the Bjorken sum rule bound. The effect of the Omega_Q^* -
Omega_Q mass splitting on the first-order form factors is examined.


title:
Resolved Photon Contributions to Leptoquark Production in $e^+ e^-$ and
  $e\gamma$ Collision

abstract:
  We calculate the resolved photon contribution to leptoquark production at
$e\gamma$ colliders for the center of mass energies $\sqrt s=500$~GeV and
1~TeV. We also calculate the resolved photon contribution to leptoquark
production at $e^+ e^-$ colliders for the center of mass energies $\sqrt{s} =
1$~and~2~TeV. In both cases we find that these contributions are considerably
larger than the standard contributions considered in the literature.


title:
1) Spin and flavor sum rules based on a parton model, 2) SU(2) flavor
  breaking in antiquark distributions

abstract:
  1) We discuss a sum rule of the tensor structure function $b_1(x)$ for
spin-one hadrons along with the Gottfried sum rule. Both sum rules are similar
in the sense that they are phenomenological ones based on a naive parton model.
As the Gottfried sum rule became useful for studying SU(2)$_{flavor}$ breaking
in antiquark distributions, the $b_1$ sum rule could provide important
information on sea-quark tensor polarization.
  2) Pionic contributions to the antiquark distribution $\bar u-\bar d$ and
violation of the Gottfried sum rule are discussed. We find that the
contributions account for about half of the discrepancy found by the New Muon
Collaboration between their result and the sum rule. In order to distinguish
various theoretical explanations, we need independent experimental tests, for
example, by using Drell-Yan processes. As an application of mesonic
calculations, the difference between strange and antistrange quark
distributions in the nucleon is briefly discussed.


title: Dijet Production at Large Rapidity Intervals

abstract:
  We examine dijet production at large rapidity intervals at Tevatron energies,
by using the theory of Lipatov and collaborators which resums the leading
powers of the rapidity interval. We analyze the growth of the Mueller-Navelet
$K$-factor in this context and find it to be negligible. However, we do find a
considerable enhancement of jet production at large transverse momenta. In
addition, we show that the correlation in transverse momentum and azimuthal
angle of the tagging jets fades away as the rapidity interval is increased.


title: Spacetime Symmetries and Semiclassical Amplitudes

abstract:
  We examine the spacetime symmetries of forward $2 \rightarrow 2$ scattering.
These symmetries have non-trivial consequences for any class of configurations
which might dominate the amplitude in the semiclassical approximation. We
derive some dynamical results regarding the stability of configurations which
arise solely from reflection symmetry and positivity of the (Euclidean) path
integral action. We show that in the case of on-shell scattering, any
semiclassical configuration must have $O(3)$ symmetric asymptotic behavior. We
argue that non--$O(3)$ symmetric configurations are irrelevant to the
semiclassical exponent.


title: Vibrational Aspects of the SU(2) Skyrmion

abstract:
  We treat the Skyrme model with the breathing mode in a situation involving
two quartic terms. It is seen that there is a new limit for large $e$ due to
the breathing mode not found in the usual rotating hedgehog.


title: On soft breaking and CP phases in the supersymmetric standard model

abstract:
  We consider a class of N=1 supersymmetric extensions of the Standard Model in
which the soft breaking sector is CP conserving at the GUT scale. We study the
question of whether the presence of explicit CP violation in the Yukawa sector
of the theory induces through renormalization effects CP violating phases in
the soft terms, which could lead to observable effects. A clear pattern appears
in the structure of phases in the soft sector. In particular, the inclusion of
intergenerational mixing induces large phases in the flavour mixing entries of
the trilinear soft breaking terms, whereas the diagonal entries remain real. A
mechanism is proposed for generating through chargino exchange a contribution
to the neutron electric dipole moment which can be a few orders of magnitude
larger that that of the Standard Model, although still out of reach of
experimental tests. We comment on the possible relevance of these phases for
baryogenesis at the weak scale in minimal supersymetric scenarios, recently
considered in the literature.


title: On near forward high energy scattering in QCD

abstract:
  We consider elastic quark-quark scattering at high energy and fixed
transferred momentum. Performing factorization of soft gluon exchanges into
Wilson lines vacuum expectation values and studying their properties, we find
that the asymptotics of the scattering amplitude is controlled by the
renormalization properties of the so called cross singularities of Wilson
loops. Using this fact, we evaluate the scattering amplitude and show that its
asymptotics is determined by the properties of the $2\times 2$ matrix of
anomalous dimensions which appears after one renormalizes the cross
singularities of Wilson loops. A generalization to the case of quark-antiquark
and gluon-gluon elastic scattering is discussed.


title:
What can we learn from new measurements of Dalitz plot parameters for K
  $\rightarrow 3 \pi$ decays ?

abstract:
  We give a simple expression in linear and quadratic Dalitz--plot slopes which
does not depend on the charge combination of the $3\pi$ state $(K^\pm \to
\pi^{\pm}\pi^{+}\pi^{-}$ or $\pi^{\pm}\pi^{0}\pi^{0}$ and $K_L^{0} \to
\pi^{+}\pi^{-}\pi^{0}$ or $\pi^{0}\pi^{0}\pi^{0})$, if all phases between final
states are negligible. After investigating the influence of radiative
corrections, it is shown how new measurements, especially of quadratic slopes
in the $\pi^{\pm} \pi^{0} \pi^{0}$ channel, could help to test theoretical
predictions more stringently. A FORTRAN code for the radiatiative corrections
is available on request.


title: Scattering in the Presence of Electroweak Phase Transition Bubble Walls

abstract:
  We investigate the motion of fermions in the presence of an electro\-weak
phase transition bubble wall. We derive and solve the Dirac equation for such
fer\-mions, and compute the transmission and reflection coefficients for
fermions traveling from the symmetric to the asymmetric phases separated by the
domain wall.


title: Signals for Vector Leptoquarks in Hadronic Collisions

abstract:
  We analyze systematically the signatures of vector leptoquarks in hadronic
collisions. We examine their single and pair productions, as well as their
effects on the production of lepton pairs. Our results indicate that a machine
like the CERN Large Hadron Collider (LHC) will be able to unravel the existence
of vector leptoquarks with masses up to the range of $2$--$3$ TeV.


title: A Large Majorana-Mass From Calabi-Yau Superstring Models

abstract:
  In Calabi-Yau superstring models it is found that two large intermediate
energy scales of symmetry breaking can be induced for special types of the
nonrenormalizable interactions. In the models one set of $SO(10)$-singlet,
right-handed neutrino and their mirror chiral superfields is needed. Through
the study of the minimization of the scalarpotential, the conditions for the
presence of two large intermediate scales are obtained. In this scheme a
Majorana-mass possibly amounts to $O(10^{9 \sim 10}\gev)$. This large
Majorana-mass solves the solar neutrino problem and also is compatible with the
cosmological bound for stable light neutrinos.


title:
Higher Resonance Contributions to the Adler-Weisberger Sum Rule in the
  Large N_c Limit

abstract:
  We determine the $N_c$--dependence of the resonance contributions to the
Adler--Weisberger sum rule for the inverse square $1/g_A^2$ of the axial charge
coupling constant and show that in the large $N_c$ limit the contributions of
the Roper-like excitations scale as $O(1/N_c)$. Consistency with the $1/N_c^2$
scaling of the $1/g_A^2$ term in the sum rule requires these contributions to
cancel against each other.


title: Supersymmetry and Light Quark Masses in a Realistic Superstring Model

abstract:
  We examine the light quark masses in a standard--like superstring model in
the four dimensional free fermionic formulation. We find that the supersymmetry
constraints in the observable and hidden sectors eliminate all large
contributions to $m_u$ and $m_d$ and force them to be much smaller than the
other quark masses. The requirement for an acceptable Higgs doublet spectrum
results in $m_u<<m_d$. In these models a realistic $m_d$ can always be obtained
whereas $m_u$ is at most $10^{-5}~MeV$. For particular choices of flat
directions or vacua $m_u$ can be as small as $10^{-7}~MeV$ but cannot vanish.


title:
Monofractal Density Fluctuations and Scaling Laws for Count
  Probabilities and Combinants

abstract:
  The relation of combinants to various statistics characterizing the
fluctuation pattern of multihadron final states is discussed. Scaling laws are
derived for count probabilities and combinants in the presence of homogeneous
and clustered monofractal density fluctuations. It is argued that both types of
scaling rules are well suited to signal Quark-Gluon Plasma formation in a
second-order QCD phase transition.


title: Status of QCD

abstract:
  I have been asked to discuss the status of QCD. It seems to me that there are
three main points to be made about the present status of QCD: $\bullet$ QCD is
right, and we can do many beautiful things with it. $\bullet$ There are several
important concrete problems that lie just beyond the edge of our current
understanding. $\bullet$ There are some foundational issues in QCD, and some
recent developments, that may point toward entirely new directions. These
points will, I believe, emerge quite clearly from the following more detailed
discussion. The discussion will be in three parts. I'll first discuss
elementary processes, then more complicated processes, and then finally
foundational issues.


title: Five Jet Production with Heavy Quarks at $e^+ e^-$ Colliders

abstract:
  Heavy quark production in five jet events at $e^+e^-$ colliders is studied at
tree level using helicity amplitudes. Total production rates for $2b3j$ and
$4bj$ are given and compared with the corresponding results for massless
quarks. The process $e^+e^-\rightarrow q\bar q gg\gamma$ which is the dominant
contribution to $4j\gamma$ production is briefly discussed.


title: Strong Decays of Strange Charmed P-Wave Mesons

abstract:
  Goldstone boson decays of P-wave $D_s^{**}$ mesons are studied within the
framework of Heavy Hadron Chiral Perturbation Theory. We first analyze the
simplest single kaon decays of these strange charmed mesons. We derive a model
independent prediction for the width of $D_{s2}$ and use experimental
information on $D_{s1}$ to constrain the S-wave contribution to $D_1^0$ decay.
Single and double pion decay modes are then discussed and shown to be
significantly restricted by isospin conservation. We conclude that the pion
channels may offer the best hope for detecting one strange member of an
otherwise invisible P-wave flavor multiplet.


title: Supersymmetry Anomalies, the Witten Index and the Standard Model

abstract:
  The supersymmetric standard model (SSM) contains a wealth of potential
supersymmetry anomalies, all of which occur in the renormalization of composite
operators of the theory. The coefficients of the weak-E.M. superanomalies
should be related to the Witten indices of the neutrino and photon superfields,
and the coefficients of the strong superanomalies should be related to the
Witten indices of the gluon and photon superfields. Assuming the coefficients
are non-zero, the superanomalies break supersymmetry in observable states.
However the neutral Higgs particles should remain in a supermultiplet because
the Higgs supermultiplet is not coupled to any massless superfield in the SSM.
Assuming that the overall Witten index is non-zero, supersymmetry is broken by
superanomalies and yet the vacuum remains supersymmetric. This means that the
cosmological constant is naturally zero after supersymmetry breaking, even
beyond perturbation theory.


title:
New Constraints on Neutrino Oscillations in Vacuum as a Possible
  Solution of the Solar Neutrino Problem

abstract:
  Two-neutrino oscillations in vacuum are studied as a possible solution of the
solar neutrino problem. New constraints on the parameter sn2, characterizing
the mixing of the electron neutrino with another active or sterile neutrino, as
well as on the mass--squared difference, dm2, of their massive neutrino
components, are derived using the latest results from the four solar neutrino
experiments. Oscillations into a sterile neutrino are ruled out at 99 % C.L. by
the observed mean event rates even if one includes the uncertainties of the
standard solar model predictions in the analysis.


title: General Determination of Phases in Leptonic Mass Matrices

abstract:
  We construct new invariants and give several theorems which determine in
general (i) the number of physically meaningful phases in charged lepton and
neutrino mass matrices and (ii) which elements of these matrices can be
rendered real by rephasings. We illustrate our results with simple models.


title: Hadronic Event Shapes in $B$ Decay

abstract:
  We compute the differential momentum correlation function for hadrons
produced in the decay of $B$-mesons. This measure of hadronic event shapes
tests the free $b$-quark decay picture for nonleptonic and semileptonic decays
of $B$-mesons. Our results can also be applied to $B_s$ and $\Lambda_b$ decay.


title: Hadrons of Arbitrary Spin and Heavy Quark Symmetry

abstract:
  We present a general construction of the spin content of the Bethe-Salpeter
amplitudes (covariant wave functions) for heavy hadrons with arbitrary orbital
excitations, using representations of the Lorentz group. These wave functions
incorporate the symmetries manifest in the heavy quark limit. In the baryonic
sector we clearly differentiate between the $\Lambda$ and $\Sigma$ type excited
baryons. We then use the trace formalism to evaluate the weak transitions of
ground state heavy hadrons to arbitrary excited heavy hadrons. The
contributions of excited states to the Bjorken sum rule are also worked out in
detail.


title:
The Neutrino Mass Spectrum in the Supersymmetric Flipped SU(5)xU(1) GUT
  Model

abstract:
  In the context of the supersymmetric flipped $SU(5)\otimes U(1)$ GUT model,
we have studied in detail the neutrino mass spectrum, obtaining an approximate
formula for the corresponding effective three-generation mass matrix. It is
found that at least two neutrinos are expected to have extremely small masses
of no particular interest. The third neutrino, on the other hand, may
eventually get a mass of order $10^{-3}$ eV, of relevance for the solution of
the solar neutrino problem with the MSW mechanism, as a consequence of
vacuum-expectation-values at the GUT mass scale for some of the scalar partners
of the right-handed neutrinos.


title:
Recent Progress in Understanding Quark and Gluon Distribution Functions
  for Large Nuclei at Small x

abstract:
  I discuss the problem of computing the structure functions for very heavy
nuclei at small Bjorken x. The approximations used in this description are
physically motivated, and recent computations reviewed.


title:
Z_2\times Z_2$ orbifold compactification as the origin of realistic free
  fermionic models

abstract:
  I discuss the correspondence between realistic four dimensional free
fermionic models and $Z_2\times Z_2$ orbifold compactification. %I illustrate
this correspondence for one particular example. I discuss the properties of the
$Z_2\times Z_2$ orbifold that are reflected in the realistic free fermionic
models. I argue that the properties of the realistic free fermionic models
arise due to the underlying $Z_2\times Z_2$ orbifold compactification with
nontrivial background fields. I suggest that three generation is a natural
outcome of $Z_2\times Z_2$ orbifold compactification with ``standard
embedding'' and at the point in compactification space that corresponds to the
free fermionic formulation. I discuss how quark flavor mixing is related to the
compactification.


title:
How Strong is the Evidence for Electroweak Corrections Beyond the
  Running of $\alpha$?

abstract:
  The evidence for electroweak radiative corrections not contained in
$\alpha(m_Z)$ is examined. At low energies there is very strong evidence in the
analysis of the unitarity of the CKM matrix. At LEP and collider experiments
the current direct signals are not strong, but there is substantial indirect
evidence, which will likely become sharper when $m_t$ is determined. The
advantage of using $(\Delta r)_{res}$ as a measure of these effects is
emphasized. In order to improve the direct evidence, more accurate measurements
of $m_W$ and the on--resonance asymmetries are indicated.


title:
Prediction of beauty particle masses with the heavy quark effective
  theory (II)

abstract:
  The effective theory for heavy quarks has additional symmetries with respect
to QCD, which relate charm and beauty hadron masses. Assuming the spectrum of
charmed particles, we predicted in a previous work the masses of some beauty
particles. The predictions of the Lambda_b mass, M(Lambda_b)=5630 MeV, and of
the B_s mass, M(B_s)=5379 MeV, are in agreement with present experimental data.
We continue this work using recent experimental data on charm hadron masses.
The results are: M(Sigma_b)=5822+-6 MeV, M(Sigma_b*)-M(Sigma_b)=33+-3 MeV,
M(Omega_b)=6080+-7 MeV, M(Omega_b*)-M(Omega_b)=32+-3 MeV, M(Lambda_b*)=5945+-3
MeV, M(Lambda_b**)-M(Lambda_b*)=15+-1 MeV. When experimental data for beauty
hadron masses are available, a comparison with the theoretical values allows a
quantitative estimate of the corrections to the static theory, which contain
informations on hadron dynamics at low energy.


title:
Dimensional Continuation of Gauge-Invariant Quantities in Yang-Mills
  Theory

abstract:
  Consideration of some perturbatively calculated gauge-invariant expectation
values of local noncomposite operators in pure Yang-Mills theory indicates that
those expectation values which are not dimension specific, and which are well
defined near $D=4$ dimensions, have some {\it finite} limit as the evaluated
expression is naively extrapolated from $D=4$ to $D=2$. If this finite limit is
a generic feature for such quantities it would not only be quite remarkable but
also of some utility : For example, one may then use it as a convenient
necessary condition when checking gauge invariance. Some examples are discussed
at nonzero temperature.


title: Hadronic Contributions to the Muon $g-2$ and Low-Energy QCD

abstract:
  The contributions to the muon anomalous magnetic moment from hadronic vacuum
polarization and from hadronic light-by-light scattering are reexamined within
the frame work of chiral perturbation theory; the $1/N_c$-expansion; and the
extended Nambu Jona-Lasinio model of low-energy QCD.


title:
Maximally-Mixed Three Generations of Neutrinos and the Solar and
  Atmospheric Neutrino Problems

abstract:
  Motivated by the indication that both the Solar and the atmospheric neutrino
puzzles may simultaneously be solved by (vacuum as well as matter-induced
resonant) oscillations of two generations of neutrinos with large mixing, we
have analyzed the data on the Solar and atmospheric neutrinos assuming that all
{\it three} neutrinos are maximally mixed. It is shown that the results of
two-generation analyses are still valid even in the three-generation scheme,
{\it i.e.}, the two puzzles can be solved simultaneously if $\Delta m_{21}^2 =
m_2^2-m_1^2\simeq 10^{-10}\mbox{eV}^2$ and $\Delta m_{31}^2 = 10^{-3}\sim
10^{-1}\mbox{eV}^2$. We have also demonstrated explicitly that with the use of
the see-saw mechanism it is possible to have large or maximal mixings for
neutrinos even though their masses are highly non-degenerate.


title: Kaon decay interferometry as meson dynamics probes

abstract:
  We discuss the time dependent interferences between $K_L$ and $K_S$ in the
decays in $3\pi$ and $\pi\pi\gamma$, to be studied at interferometry machines
such as the $\phi$-factory and LEAR. We emphasize the possibilities and the
advantages of using interferences, in comparison with width measurements, to
obtain information both on $CP$ conserving and $CP$ violating amplitudes.
Comparison with present data and suggestions for future experiments are made.


title: The Cutoff $\lambda \phi^4$ O(N) Model in the Large N Limit

abstract:
  A cutoff version of the $\lambda \phi^4$ O(N) model is considered to leading
order in 1/N with particular attention to the effective potential, which is
surprisingly rich in structure. With suitable restriction on a background
classical field, one finds a phenomenologically viable model with spontaneously
broken symmetry, a potential bounded below, and amplitudes free of tachyons.
The model has an O(N-1) singlet resonance in both weak and strong coupling,
which can be interpreted as the Higgs meson in applications. Further, an
unphysical resonance, which can be used to define a triviality scale for the
model, appears at a mass above the cutoff mass $\L$. The phenomelogical aspects
of our discussion are consistent with previous studies of closely related
models by Heller, {\it et al.}
  The question of the double-scaling limit for the cutoff model is considered
as an application of the effective potential. It is shown that the
double-scaling limit is not possible.


title: An Extended Technicolor Model

abstract:
  An extended technicolor model is constructed. Quark and lepton masses,
spontaneous CP violation, and precision electroweak measurements are discussed.
Dynamical symmetry breaking is analyzed using the concept of the BIG MAC.


title: Prediction for Nonabelian Fine Structure Constants from Multicriticality

abstract:
  In developing a model for predicting the nonabelian gauge coupling constants
we argue for the phenomenological validity of a ``principle of multiple point
criticality''. This is supplemented with the assumption of an ``(grand)
anti-unified'' gauge group $SMG^{N_{gen.}}\sim U(1)^{N_{gen.}}\times
SU(2)^{N_{gen.}}\times SU(3)^{N_{gen.}}$ that, at the Planck scale, breaks down
to the diagonal subgroup. Here $N_{gen}$ is the number of generations which is
assumed to be 3. According to this ``multiple point criticality principle'',
the Planck scale experimental couplings correspond to multiple point couplings
of the bulk phase transition of a lattice gauge theory (with gauge group
$SMG^{N_{gen.}}$). Predictions from this principle agree with running
nonabelian couplings (after an extrapolation to the Planck scale using the
assumption of a ``desert'') to an accuracy of 7\%. As an explanation for the
existence of the multiple point, a speculative model using a glassy lattice
gauge theory is presented.


title: Charmonium Production via Fragmentation

abstract:
  We present the preliminary results of a calculation of the fragmentation
contribution to charmonium production at large transverse momentum in
$p\bar{p}$ colliders. The fragmentation of gluons and charm quarks is the
dominant direct production mechanism for sufficiently large $p_{\perp}$. We
find that for both $J/\psi$ and $\psi '$ production fragmentation dominates
over the conventional gluon-gluon fusion mechanism for $p_{\perp}$ greater than
about 6 GeV.} Presented at the Workshop on Physics at Current Accelerator and
the Supercollider, Argonne National Laboratory, June 1993.


title:
On the Evaluation of Threshold Effects in Processes Involving Heavy
  Quarks

abstract:
  A detailed evaluation is presented of production of heavy fermions
(particularly ttbar quarks) by a vector current, in the region around
threshold. This includes bound states as well as the region above threshold, to
the same degree of accuracy; in both cases radiative and nonperturbative
corrections are included. The contribution of this region to the vacuum
polarization (``threshold effects'') is calculated and compared with a
perturbative calculation; the importance of the threshold effects is found
substantially smaller than claimed by some authors. Open fermion-antifermion
production is also discussed.


title: Field Theoretical Background for Thermal Physics

abstract:
  Techniques of zero-temperature field theory that have found application in
the analysis of field theory at finite temperature are revisited. Specifically,
several of the results that are discussed are relevant to the study of
symmetry-changing phase transitions and high temperature QCD, which today are
among the most actively investigated problems in finite temperature field
theory.


title:
QCD-Based Interpretation of the Lepton Spectrum in Inclusive $\bar B\to
  X_u\,\ell\,\bar\nu$ Decays

abstract:
  We present a QCD-based approach to the endpoint region of the lepton spectrum
in $\bar B\to X_u\,\ell\,\bar\nu$ decays. We introduce a genuinely
nonperturbative form factor, the shape function, which describes the fall-off
of the spectrum close to the endpoint. The moments of this function are related
to forward scattering matrix elements of local, higher-dimension operators. We
find that nonperturbative effects are dominant over a finite region in the
lepton energy spectrum, the width of which is related to the kinetic energy of
the $b$-quark inside the $B$ meson. Applications of our method to the
extraction of fundamental standard model parameters, among them $V_{ub}$, are
discussed in detail.


title: Chaotic Inflation and Baryogenesis in Supergravity

abstract:
  We propose a K\"ahler potential in supergravity which successfully
accommodates chaotic inflation. This model can have a large gravitino mass
without giving a large mass to squarks and sleptons, and thus is free from both
the gravitino problem and entropy crisis. In this model baryogenesis takes
place naturally, identifying the inflaton with a right-handed sneutrino with
its mass $M \simeq 10^{13}$GeV, which is consistent with the COBE data and the
Mikheyev--Smirnov--Wolfenstein solution to the solar neutrino problem. The
model can also accommodate the matter content appropriate for the mixed dark
matter scenario.