title: Bilocal Dynamics for Self-Avoiding Walks

abstract:
  We introduce several bilocal algorithms for lattice self-avoiding walks that
provide reasonable models for the physical kinetics of polymers in the absence
of hydrodynamic effects. We discuss their ergodicity in different confined
geometries, for instance in strips and in slabs. A short discussion of the
dynamical properties in the absence of interactions is given.


title: Implications of $Tr\gamma_{5}=0$ in Lattice Gauge Theory

abstract:
  We analyze the implications of the relation $Tr\gamma_{5}=0$, which is
customarily assumed in practical lattice calculations. On the basis of the
finite dimensional representations of the Ginsparg-Wilson algebra, it is shown
that this relation reflects the species doubling in lattice theory; topological
excitations associated with species doublers, which have eigenvalue $2/a$,
contribute to $Tr\gamma_{5}$ without any suppression. In this sense, the
relation $Tr\gamma_{5}=0$ is valid only when we allow the presence of
unphysical states in the Hilbert space; this statement is also valid in the
Pauli-Villars regularization. If one eliminates the contributions of the
unphysical states, the trace $Tr\gamma_{5}$ is replaced by $Tr\Gamma_{5}\equiv
Tr \gamma_{5}(1 -{1/2}aD)$ which gives rise to the Pontryagin index, to be
consistent with the continuum analysis.


title:
Renormalization group flow of SU(3) lattice gauge theory - Numerical
  studies in a two coupling space

abstract:
  We investigate the renormalization group (RG) flow of SU(3) lattice gauge
theory in a two coupling space with couplings $\beta_{11}$ and $\beta_{12}$
corresponding to $1\times 1$ and $1\times 2$ loops respectively. Extensive
numerical calculations of the RG flow are made in the fourth quadrant of this
coupling space, i.e., $\beta_{11}>0$ and $\beta_{12}<0$. Swendsen's factor two
blocking and the Schwinger-Dyson method are used to find an effective action
for the blocked gauge field. The resulting renormalization group flow runs
quickly towards an attractive stream which has an approximate line shape. This
is numerical evidence of a renormalized trajectory which locates close to the
two coupling space. A model flow equation which incorporates a marginal
coupling (asymptotic scaling term), an irrelevant coupling and a
non-perturbative attraction towards the strong coupling limit reproduces
qualitatively the observed features. We further examine the scaling properties
of an action which is closer to the attractive stream than the currently used
improved actions. It is found that this action shows excellent restoration of
rotational symmetry even for coarse lattices with $a \sim 0.3$ fm.


title:
Effects of Chemical Potential on Hadron Masses in the Phase Transition
  Region

abstract:
  We study the response of hadron masses with respect to chemical potential at
$\mu=0$. Our preliminary results of the pion channel show that $\partial
m/\partial \mu$ in the confinement phase is significantly larger than that in
the deconfinement phase, which is consistent with the chiral restoration.


title: Glueballs on a transverse lattice

abstract:
  Accurate non-perturbative calculations of glueballs are performed using
light-front quantised SU(N) gauge theory, to leading order of the 1/N
expansion. Based on early work of Bardeen and Pearson, disordered
gauge-covariant link variables M on a coarse transverse lattice are used to
approximate the physical gauge degrees of freedom. Simple energetics imply
that, at lattice spacings of order the inverse QCD scale, the effective
light-front Hamiltonian can be expanded in gauge-invariant powers of M: a
colour-dielectric expansion. This leads to a self-consistent constituent
structure of boundstates. We fix the couplings of this expansion by optimising
Lorentz covariance of low-energy eigenfunctions. To lowest non-trivial order of
the expansion, we have found a one-parameter trajectory of couplings that
enhances Lorentz covariance. On this trajectory the masses of nearly-covariant
glueball states exhibit approximate scaling, having values consistent with
large-N extrapolations of continuum results from other methods. There is very
little variation with N in pure Yang-Mills theory: the lightest glueball mass
changes by only a few percent between SU(3) and SU(infinity). The corresponding
light-front wavefunctions show an unconventional structure. We also examine
restoration of rotational invariance in the heavy-source potential.


title:
$B \to \pi l\bar{\nu}$ Form Factors with NRQCD Heavy Quark and Clover
  Light Quark Actions

abstract:
  We report results on semileptonic $B\to\pi l\bar{\nu}$ decay form factors
near $q^2_{\rm max}$ using NRQCD heavy quark and clover light quark actions and
currents improved through $O(\alpha a)$. An inconsistency with the soft pion
relation $f^0(q^2_{\rm max})= f_B/f_{\pi}$ found in a previous work is
confirmed, and a possible solution with nonperturbative renormalization is
discussed. We find that $f^+(q^2)$ is well described by the $B^*$ pole near
$q^2_{\rm max}$, and its $1/M_B$ scaling is also consistent with the prediction
of the pole dominance model.


title: One-loop analyses of lattice QCD with the overlap Dirac operator

abstract:
  We discuss the weak coupling expansion of lattice QCD with the overlap Dirac
operator. The Feynman rules for lattice QCD with the overlap Dirac operator are
derived and the quark self-energy and vacuum polarization are studied at the
one-loop level. We confirm that their divergent parts agree with those in the
continuum theory.


title: Lattice Gauge Fixing for Parameter Dependent Covariant Gauges

abstract:
  We propose a non-perturbative procedure to fix generic covariant gauges on
the lattice. Varying the gauge parameter, this gauge fixing provides a concrete
method to check numerically the gauge dependence of correlators measured on the
lattice. The new algorithm turns out to converge with a good efficiency. As a
preliminary physical result, we find a sensitive dependence of the gluon
propagator on the gauge parameter.


title:
Heavy-light spectrum and decay constant from NRQCD with two flavors of
  dynamical quarks

abstract:
  We report on a study of B mesons on N_f = 2 full QCD configurations using an
RG-improved gauge action, NRQCD heavy quark action and tadpole-improved clover
light quark action. Results on the heavy-light spectrum and the decay constants
from 16^3x32 lattices at a^{-1} ~ 1.5 GeV are presented, and compared with
quenched results obtained with the same action combination at matching lattice
spacings.


title: Light Hadron Spectrum in Quenched Lattice QCD with Staggered Quarks

abstract:
  Without chiral extrapolation, we achieved a realistic nucleon to (\rho)-meson
mass ratio of (m_N/m_\rho = 1.23 \pm 0.04 ({\rm statistical}) \pm 0.02 ({\rm
systematic})) in our quenched lattice QCD numerical calculation with staggered
quarks. The systematic error is mostly from finite-volume effect and the
finite-spacing effect is negligible. The flavor symmetry breaking in the pion
and (\rho) meson is no longer visible. The lattice cutoff is set at 3.63 (\pm)
0.06 GeV, the spatial lattice volume is (2.59 (\pm) 0.05 fm)(^3), and bare
quarks mass as low as 4.5 MeV are used. Possible quenched chiral effects in
hadron mass are discussed.


title:
Some Pieces of Lattice Evidence in Favor of the Center-Vortex Picture of
  Color Confinement

abstract:
  We address two questions related to the procedure of identifying center
vortices based on center projection in maximal center gauge: 1. How does the
procedure work, why is it expected to locate center vortices relevant for
confinement, and why does it in some cases fail, on lattice configurations
preconditioned in a special way? 2. Does the mechanism work the same way for 3
colors instead of 2? (The paper is an abridged version of two recent e-prints,
hep-lat/9910033 and hep-lat/9911006.)


title:
Center vortex model for the infrared sector of Yang-Mills theory -
  Confinement and Deconfinement

abstract:
  A model for the infrared sector of Yang-Mills theory based on magnetic
vortices represented by (closed) random surfaces is investigated using lattice
Monte Carlo methods. The random surfaces are governed by a surface area action
and a curvature action. The model generates a finite-temperature deconfinement
transition; the coupling constants of the model can be chosen such as to
reproduce the SU(2) Yang-Mills ratio of the deconfinement temperature to the
square root of the zero-temperature string tension, T_c / sqrt{sigma_0} =0.69.
This yields a physical trajectory in the space of coupling constants on which
the confinement properties are approximately invariant. An at first sight
surprisingly accurate prediction of the spatial string tension in the
deconfined phase results, which can be made plausible in view of the specific
space-time structure of the vortex configurations in this phase. The
confinement properties are shown to be intimately tied to the percolation
properties of the vortex surfaces.


title:
Microscopic Universality and the Chiral Phase Transition in two Flavor
  QCD

abstract:
  We re-analyze data from available finite-temperature QCD simulations near the
chiral transition, with the help of Chiral Random Matrix Theory (chRMT).
Statistical properties of the lowest-lying eigenvalues of the staggered Dirac
operator for SU(3) lattice gauge theory with dynamical fermions are examined.
We consider temperatures below, near, and above the critical temperature $T_c$
for the chiral phase transition. Below and above $T_c$ the statistics are in
agreement with the exact analytical predictions in the microscopic scaling
regime. Above $T_c$ we observe a gap in the spectral density and a distribution
compatible with the Airy distribution. Near $T_c$ the eigenvalue correlations
appear inconsistent with chRMT.


title: Topologically invariant transformation for lattice fermions

abstract:
  A transformation is devised to convert any lattice Dirac fermion operator
into a Ginsparg-Wilson Dirac fermion operator. For the standard Wilson-Dirac
lattice fermion operator, the transformed new operator is local, free of O(a)
lattice artifacts, has correct axial anomaly in the trivial sector, and is not
plagued by the notorious problems (e.g., additive mass renormalization) which
occur to the standard Wilson-Dirac lattice fermion operator.


title: Remarks on domain-wall Fermions

abstract:
  Domain-wall Fermions represent a recent lattice approach to chiral symmetry
that is receiving considerable attention. The method is presented in a somewhat
unconventional manner, in terms of a ladder molecule subjected to a magnetic
field. Speculations are made on extending the formalism to multiple species.


title:
Pion decay constant for the Kogut-Susskind quark action in quenched
  lattice QCD

abstract:
  We present a study for the pion decay constant $f_\pi$ in the quenched
approximation to lattice QCD with the Kogut-Susskind (KS) quark action, with
the emphasis given to the renormalization problems. Numerical simulations are
carried out at the couplings $\beta = 6.0$ and 6.2 on $32^3\times 64$ and
$48^3\times 64$ lattices, respectively. The pion decay constant is evaluated
for all KS flavors via gauge invariant and non-invariant axial vector currents
with the renormalization constants calculated by both non-perturbative method
and perturbation theory. We obtain $f_\pi = 89(6)$ MeV in the continuum limit
as the best value using the partially conserved axial vector current, which
requires no renormalization. From a study for the other KS flavors we find that
the results obtained with the non-perturbative renormalization constants are
well convergent among the KS flavors in the continuum limit, confirming
restoration of $\rm SU(4)_A$ flavor symmetry, while perturbative
renormalization still leaves an apparent flavor breaking effect even in the
continuum limit.


title: Introducing Dynamical Triangulations to the Type IIB Superstrings

abstract:
  In order to consider non-perturbative effects of superstrings, we try to
apply dynamical triangulations to the type IIB superstrings. The discretized
action is constructed from the type IIB matrix model proposed as a constructive
definition of superstring theory. The action has the local N=2 supersymmetry
explicitly, and has no extra fermionic degrees of freedom. We evaluate the
partition function for some simple configurations and discuss constraints
required from the finiteness of partition functions.


title: Computers for Lattice QCD

abstract:
  The architecture and capabilities of the computers currently in use for
large-scale lattice QCD calculations are described and compared. Based on this
present experience, possible future directions are discussed.


title: Introduction to transverse lattice gauge theory

abstract:
  I review a new treatment of an old idea for light-front quantization of
lattice gauge theories and give new results from some illustrative
calculations: [I] transverse lattice gauge theory; [II] pure glue; [III] heavy
sources and winding modes; [IV] an example -- large-N QCD in 2+1 dimensions.


title: Gauged Gross--Neveu model with overlap fermions

abstract:
  We investigate chiral properties of the overlap lattice fermion by using
solvable model in two dimensions, the gauged Gross-Neveu model. In this model,
the chiral symmetry is spontaneously broken in the presence of small but finite
fermion mass. We calculate the quasi-Nambu-Goldstone(NG) boson mass as a
function of the bare fermion mass and two parameters in the overlap formula. We
find that the quasi-NG boson mass has desired properties as a result of the
extended chiral symmetry found by L\"uscher. We also show the PCAC relation is
satisfied in desired form. Comparison between the overlap and Wilson lattice
fermions is also made.


title: Topology in QCD with 4 flavours of dynamical fermions

abstract:
  We study the topological properties of full QCD with four flavours of
dynamical staggered fermions. In particular the topological susceptibility is
measured and the problem of the determination of its first derivative is
discussed.


title: Chiral Symmetry Outside Perturbation Theory

abstract:
  Within the overlap framework, I derive the main formulae one finds today in
papers touting a ``new approach'' to the regularization of chiral gauge
theories. My main objective is to clear up an unhealthy confusion about how
many successful approaches to regulate chiral fermions on the lattice there
really are: At the moment, there is only one, the overlap, and finding a
genuinely different approach is an important and completely open problem.


title: Comment on "Percolation Properties of the 2D Heisenberg Model"

abstract: We comment on a recent paper by All\`es et al.


title: Criterium for the index theorem on the lattice

abstract:
  We study how far the Index Theorem can be extrapolated from the continuum to
finite lattices with finite topological charge densities. To examine how the
Wilson action approximates the Index theorem, we specialize in the lattice
version of the Schwinger model. We propose a new criterion for solutions of the
Ginsparg-Wilson Relation constructed with the Wilson action. We conclude that
the Neuberger action is the simplest one that maximally complies with the Index
Theorem, and that its best parameter in d=2 is m0=1.1 +- 0.1 .


title: Non Perturbative QCD

abstract:
  This series of lectures consists of two parts. In the first part the
foundations of perturbative and non perturbative formulation are discussed. The
ambiguity in the definition of vacuum condensates is then analyzed. In the
second part the symmetry patterns of the deconfining phase transition are
discussed.


title: Fermionic correlators and zero-momentum modes in quenched lattice QED

abstract:
  For the Lorentz gauge the influence of various Gribov gauge copies on the
fermion propagator is investigated in quenched compact lattice QED. Within the
Coulomb phase besides double Dirac sheets the zero-momentum modes of the gauge
fields are shown to cause the propagator to deviate strongly from the
perturbatively expected behaviour. The standard way to extract the fermion mass
fails. The recently proposed zero-momentum Lorentz gauge is demonstrated to
cure the problem.


title: Scaling tests of the improved Kogut-Susskind quark action

abstract:
  Improved lattice actions for Kogut-Susskind quarks have been shown to improve
rotational symmetry and flavor symmetry. In this work we find improved scaling
behavior of the rho and nucleon masses expressed in units of a length scale
obtained from the static quark potential, and better behavior of the Dirac
operator in instanton backgrounds.


title: Hamiltonian domain wall fermions at strong coupling

abstract:
  We apply strong-coupling perturbation theory to gauge theories containing
domain-wall fermions in Shamir's surface version. We construct the effective
Hamiltonian for the color-singlet degrees of freedom that constitute the
low-lying spectrum at strong coupling. We show that the effective theory is
identical to that derived from naive, doubled fermions with a mass term, and
hence that domain-wall fermions at strong coupling suffer both doubling and
explicit breaking of chiral symmetry. Since we employ a continuous fifth
dimension whose extent tends to infinity, our result applies to overlap
fermions as well.


title: Summary Talk at Chiral '99

abstract:
  A brief summary of talks relating to massless lattice fermions is presented.
This summary is not a review and reading it certainly is no substitute to
reading the various original contributions.


title: Instantons and Chiral Symmetry on the Lattice

abstract:
  I address the question of how much of QCD in the chiral limit is reproduced
by instantons. After reconstructing the instanton content of smoothed Monte
Carlo lattice configurations, I compare hadron spectroscopy on this instanton
ensemble to the spectroscopy on the original ``physical'' smoothed
configurations using a chirally optimised clover fermion action. By studying
the zero mode zone in simple instances I find that the optimised action gives a
satisfactory description of it. Through the Banks-Casher formula, instantons by
themselves are shown to break chiral symmetry but hadron correlators on the
instanton backgrounds are strongly influenced by free quark propagation. This
results in unnaturally light hadrons and a small splitting between the vector
and the pseudoscalar meson channels. Superimposing a perturbative ensemble of
zero momentum gauge field fluctuations (torons) on the instantons is found to
be enough to eliminate the free quarks and restore the physical hadron
correlators. I argue that the torons that are present only in finite volumes,
are probably needed to compensate the unnaturally large finite size effects due
to the lack of confinement in the instanton ensemble.


title: Dirac operator normality and chiral fermions

abstract:
  Normality of the Dirac operator is shown to be necessary for chiral
properties.
  From the global chiral Ward identity, which in the continuum limit gives the
index theorem, a sum rule results which constrains the spectrum. The
Ginsparg-Wilson relation is to be restricted to its simple form and is a member
of a set of spectral constraints. A family of alternative chiral
transformations is introduced. The one of L\"uscher is a special case which
transports only the anomaly term to the measure. An alternative transformation
would also be needed to correct Fujikawa's path-integral approach. From a
general function of the hermitean Wilson-Dirac operator the one of Neuberger
follows.


title: Vortes solutions in nonabelian Higgs theories

abstract:
  A new class of vortex solutions is found in SU(2) gauge theories with two
adjoint representation Higgs bosons. Implications of these new solutions and
their possible connection with Center Gauge fixed pure gauge theories are
discussed.


title: Embedded vortices and their interactions at electroweak crossover

abstract:
  We study properties of Z-vortices in the crossover region of the 3D SU(2)
Higgs model. Correlators of the vortex currents with gauge field energy and
Higgs field squared ("quantum vortex profile") reveal a structure that can be
compared with a classical vortex. We define a core size and a penetration depth
from the vortex profile. Z-vortices are found to interact with each other
analogously to Abrikosov vortices in a type-I superconductor.


title:
Abelian and Nonabelian Lattice Chiral Gauge Theories through Gauge
  Fixing

abstract:
  After an introduction in which we review the fundamental difficulty in
constructing lattice chiral gauge theories, we summarize the analytic and
numerical evidence that abelian lattice chiral gauge theories can be
nonperturbatively constructed through the gauge-fixing approach. In addition,
we indicate how we believe that the method may be extended to nonabelian chiral
gauge theories.


title: Heat-Kernel Approach to the Overlap Formalism

abstract:
  We present a new regularization method, for d dim (Euclidean) quantum field
theories in the continuum formalism, based on the domain wall configuration in
(1+d) dim space-time. It is inspired by the recent progress in the chiral
fermions on lattice. The wall "height" is given by 1/M, where M is a
regularization mass parameter and appears as a (1+d) dim Dirac fermion mass.
The present approach gives a {\it thermodynamic view} to the domain wall or the
overlap formalism in the lattice field theory. We will show qualitative
correspondence between the present continuum results and those of lattice. The
extra dimension is regarded as the (inverse) {\it temperature} t. The domains
are defined by the {\it directions} of the "system evolvement", not by the sign
of M as in the original overlap formalism. We take the 4 dim QED and 2 dim
chiral gauge theory as examples. Especially the consistent and covariant
anomalies are correctly obtained.


title: Better Domain-Wall Fermions

abstract:
  We discuss two modifications of domain-wall fermions, aimed to reduce the
chiral-symmetry violations presently encountered in numerical simulations.


title: Short Strings and New Physics Perspectives in QCD

abstract:
  Within the (dual) Abelian Higgs model, confining strings do not disappear at
small distances but rather become short strings. In compact 3D electrodynamics,
as we argue here, the confining strings are also manifested at small distances
in unusual power corrections, disobeying the standard rules of the Operator
Product expansion. In the most interesting case of QCD, there is yet no
derivation of short strings and we turn to phenomenology to find evidence pro
or contra their existence. The short strings in QCD lead to non-standard power
corrections. A tentative conclusion of the analysis of existing data, both in
numerical simulations and in real experiments, is that the novel power
corrections are present, at least at the mass scale of 1-2 GeV.


title: Some Considerations on Lattice Gauge Fixing

abstract:
  Some problems related to Gribov copies in lattice gauge-fixing and their
possible solution are discussed.


title:
Some Answered and Unanswered Questions About the Structure of the Set of
  Fermionic Actions with GWL Symmetry

abstract:
  Several issues related to the question "How simple can Ginsparg-Wilson
fermionic actions be?" are discussed, and it is suggested that simplicity in
the eigenspace should be looked for.


title:
Determining Lines of Constant Physics in the Confinement Phase of the
  SU(2) Higgs Model

abstract:
  We present a method for finding lines of constant physics in the confinement
phase of the SU(2) Higgs model on the lattice. The model is considered at
finite values of the cut-off where it behaves like an effective field theory
with three independent couplings. In particular, a renormalised quantity
sensitive to a variation of the bare Higgs quartic self-coupling is constructed
from generalised Binder cumulants. Numerical results for the non-perturbative
matching of the bare parameters of the model between beta=2.2 and beta=2.4 are
presented.


title: Hyperscaling in the Broken Symmetry Phase of Dyson's Hierarchical Model

abstract:
  We use polynomial truncations of the Fourier transform of the local measure
to calculate the connected q-point functions of Dyson's hierarchical model in
the broken symmetry phase. We show that accurate values of the connected 1, 2
and 3 point functions can be obtained at large volume and in a limited range of
constant external field coupled linearly to the field variable. We introduce a
new method to obtain the correct infinite volume and zero external field
extrapolations. We extract the leading critical exponents and show that they
obey the scaling and hyperscaling relations with an accuracy ranging from 10^-5
to 5 10^-3. We briefly discuss how to improve the method of calculation.


title:
Techniques for using the overlap-Dirac operator to calculate hadron
  spectroscopy

abstract:
  We report on our progress in using the overlap-Dirac fermion operator in
simulations of lattice QCD. We have investigated the Lanczos based method of
Borici, as well as various rational approximations, to calculate the step
function in the overlap-Dirac operator. The QCD simulations were performed at
beta = 5.85 with a lattice volume of 8**3*32.


title: Heavy-light Mesons and Baryons with b quarks

abstract:
  We present lattice results for the spectrum of mesons containing one heavy
quark and of baryons containing one or two heavy quarks. The calculation is
done in the quenched approximation using the NRQCD formalism for the heavy
quark. We analyze the dependence of the mass splittings on both the heavy and
the light quark masses. Meson P-state fine structure and baryon hyperfine
splittings are resolved for the first time. We fix the b quark mass using both
M_B and M_{\Lambda_b}, and our best estimate is m_b^\MSbar(m_b^\MSbar) =
4.35(10)({}^{-3}_{+2})(10) GeV. The spectrum, obtained by interpolation to m_b,
is compared with the experimental data.


title: Some Considerations on Chiral Gauge Theories

abstract:
  Some general considerations on the problem of non-perturbative definition of
Chiral Gauge Theories are presented.


title: Preliminary Results with Lattice Covariant Gauge

abstract:
  In this poster we present a few preliminary results obtained using our method
to fix generic covariant gauges on the lattice. We have computed the gluon
propagator and we have found a sensitive dependence on the gauge parameter.


title: Remarks on Lattice Gauge Fixing

abstract:
  In this talk I briefly comment on the conventional lattice gauge fixing
adopting a critical, even though constructive, numerical point of view.


title: The Strongly Coupled 't Hooft Model on the Lattice

abstract:
  We study the strong coupling limit of the one-flavor and two-flavor massless
't Hooft models, $large-{\cal N}_c$-color $QCD_2$, on a lattice. We use
staggered fermions and the Hamiltonian approach to lattice gauge theories. We
show that the one-flavor model is effectively described by the
antiferromagnetic Ising model, whose ground state is the vacuum of the gauge
model in the infinite coupling limit; expanding around this ground state we
derive a strong coupling expansion and compute the lowest lying hadron masses
as well as the chiral condensate of the gauge theory. Our lattice computation
well reproduces the results of the continuum theory. Baryons are massless in
the infinite coupling limit; they acquire a mass already at the second order in
the strong coupling expansion in agreement with the Witten argument that
baryons are the $QCD$ solitons.
  The spectrum and chiral condensate of the two-flavor model are effectively
described in terms of observables of the quantum antiferromagnetic Heisenberg
model. We explicitly write the lowest lying hadron masses and chiral condensate
in terms of spin-spin correlators on the ground state of the spin model. We
show that the planar limit (${\cal N}_c\longrightarrow \infty$) of the gauge
model corresponds to the large spin limit ($S\longrightarrow \infty$) of the
antiferromagnet and compute the hadron mass spectrum in this limit finding
that, also in this model, the pattern of chiral symmetry breaking of the
continuum theory is well reproduced on the lattice.


title:
Analytic calculation of the 1-loop effective action for the
  O(N+1)-symmetric 2-dimensional nonlinear sigma-model

abstract:
  Polyakov's calculation of the effective action for the 2d nonlinear
sigma-Model is generalized by purely analytic means to include contributions
which are not UV-divergent and which depend on the choice of block spin. An
analytic approximation to the background field which determines the classical
perfect action is given, and approximations to the 1-loop correction are found.
The results should be useful for numerical simulations.


title:
Truncated Overlap Fermions: the link between Overlap and Domain Wall
  Fermions

abstract:
  In this talk I will emphasize the role of the Truncated Overlap Fermions in
showing the equivalence between the Domain Wall and Overlap Fermions up to an
irrelevant factor in the fermionic integration measure. I will also show how
Domain Wall type fermions with a finite number of flavors can be used to
accelerate propagator calculations of their light partner in the infinite
flavor limit.


title: Spin Effects in Heavy Hybrid Mesons on an Anisotropic Lattice

abstract:
  We present a quenched calculation of lowest bottomonium hybrid states on an
anisotropic lattice with Landau mean-link tadpole improvement, using the
improved NRQCD Hamiltonian. We investigate the quark-spin s=0,1 sectors, which
contain both the non-exotic 1-- and the exotic 1-+, and demonstrate their
degeneracy in the case of the lowest order Hamiltonian. Both states are found
at around 1.6 GeV above the Upsilon ground state. We examine the spin-splitting
for several hybrid states that is due to the magnetic moment term in the NRQCD
Hamiltonian, all other terms having negligible effect. The spin splittings are
well resolved outside errors and are surprisingly large, and we investigate
their dependence on the strength of the magnetic term. We calculate one
contribution to these splittings using the Born-Oppenheimer picture for hybrids
and show that the observed size of the effect is plausibly explained by mixing
with hybrid states with more than one constituent gluon.


title: Topology and Chiral Symmetry in QCD with Overlap Fermions

abstract:
  We briefly review the overlap formalism for chiral gauge theories, the
overlap Dirac operator for massless fermions and its connection to domain wall
fermions. We describe properties of the overlap Dirac operator, and methods to
implement it numerically. Finally, we give some examples of quenched
calculations of chiral symmetry breaking and topology with overlap fermions.


title: First experiences with HMC for dynamical overlap fermions

abstract:
  We describe an HMC algorithm for dynamical overlap fermions which makes use
of their good chiral properties. We test the algorithm in the Schwinger model.
Topological sectors are readily changed even in the massless case.


title: Symanzik Improvement In The Static Quark Potential

abstract:
  A systematic investigation of Symanzic improvement in the gauge field action
is performed for the static quark potential in quenched QCD. We consider
Symanzik improved gauge field configurations on a 16^3 X 32 lattice with a
relatively coarse lattice spacing of 0.165(2)fm. A matched set of standard
Wilson gauge configurations is prepared at \beta = 5.74 with the same physical
volume and lattice spacing and is studied for comparison. We find that, despite
the coarse lattice spacing, the unimproved and less-expensive Wilson action
does as well as the Symanzik action in allowing us to extract the static quark
potential at large qqbar separations. We have considered novel methods for
stepping off-axis in the static quark potential which provides new insights
into the extent to which the ground state potential dominates the Wilson loop
correlation function.


title:
The non-Abelian dual Meissner effect as color-alignment in SU(2) lattice
  gauge theory

abstract:
  A new gauge (m-gauge) condition is proposed by means of a generalization of
the Maximal Abelian gauge (MAG). The new gauge admits a space time dependent
embedding of the residual U(1) into the SU(2) gauge group. This embedding is
characterized by a color vector $\vec{m}(x)$. It turns out that this vector
only depends of gauge invariant parts of the link configurations. Our numerical
results show color ferromagnetic correlations of the $\vec{m}(x)$ field in
space-time. The correlation length scales towards the continuum limit. For
comparison with the MAG, we introduce a class of gauges which smoothly
interpolates between the MAG and the m-gauge. For a wide range of the gauge
parameter, the vacuum decomposes into regions of aligned vectors $\vec{m}$. The
''neutral particle problem'' of MAG is addressed in the context of the new
gauge class.


title: Renormalization of the Lattice HQET Isgur-Wise Function

abstract:
  We compute the perturbative renormalization factors required to match to the
continuum Isgur-Wise function, calculated using lattice Heavy Quark Effective
Theory. The velocity, mass, wavefunction and current renormalizations are
calculated for both the forward difference and backward difference actions for
a variety of velocities. Subtleties are clarified regarding tadpole
improvement, regulating divergences, and variations of techniques used in these
renormalizations.


title:
Decorrelation of the topological charge in tempered simulations of full
  QCD

abstract:
  The improvement of simulations of QCD with dynamical Wilson fermions by
combining the Hybrid Monte Carlo algorithm with parallel tempering is studied.
As an indicator for decorrelation the topological charge is used.


title: Lattice QCD, O.P.E. and the Standard Model

abstract:
  A number of old and new methods for computing $K\to\pi\pi$ amplitudes on the
lattice are reevaluated. They all involve a non-perturbative determination of
matching coefficients. I will show how problems related to operator mixing can
be greatly reduced by introducing the O.P.E. of hadronic currents directly on
the lattice. Applications to the evaluation of CP-symmetric ($\Delta I = 1/2$
rule) and CP-violating ($\epsilon '/\epsilon$) processes are presented.


title: Reply to Isgur's Comments on Valence QCD

abstract:
  We reply to Nathan Isgur's critique that is directed at some of the
conclusions drawn from the lattice simulation of valence QCD, regarding the
valence quark model and effective chiral theories.


title: Adjoint string breaking in 4d SU(2) Yang-Mills theory

abstract:
  We compute the static potential of adjoint sources in SU(2) Yang-Mills theory
in four dimensions by numerical Monte Carlo simulations. Following a recent
calculation in 2+1 dimensions, we employ a variational approach involving
string and gluelump operators and obtain clear evidence for string breaking and
the saturation of the potential at large distances. For the string breaking
scale we find $r_b \approx 1.25{\rm fm}, 2.3 r_0$, or in units of the lightest
glueball, $r_b m_{0++} \approx 9.7$. We furthermore resolve the first
excitation of the flux-tube and observe its breaking as well. The result for
$r_b$ is in remarkable quantitative agreement with the three-dimensional one.


title: Vortices and confinement

abstract:
  We review recent developments in the vortex picture of confinement. We
discuss numerical simulations demonstrating that the entire asymptotic string
tension is due to vortex-induced fluctuations of the Wilson loop. Analytical
and numerical results concerning the presence of vortices as the necessary and
sufficient condition for confinement at arbitrarily weak coupling in SU(N)
gauge theories are also discussed.


title: A Lattice QCD Analysis of the Strangeness Magnetic Moment of the Nucleon

abstract:
  The outcome of the SAMPLE Experiment suggests that the strange-quark
contribution to the nucleon magnetic moment, G_M^s(0), may be greater than
zero. This result is very difficult to reconcile with expectations based on the
successful baryon magnetic-moment phenomenology of the constituent quark model.
We show that careful consideration of chiral symmetry reveals some rather
unexpected properties of QCD. In particular, it is found that the valence
u-quark contribution to the magnetic moment of the neutron can differ by more
than 50% from its contribution to the Xi^0 magnetic moment. This hitherto
unforeseen result leads to the value G_M^s(0) = -0.16 +/- 0.18 with a
systematic error, arising from the relatively large strange quark mass used in
existing lattice calculations, that would tend to shift G_M^s(0) towards small
positive values.


title:
Spatial Correlation of the Topological Charge in Pure SU(3) Gauge Theory
  and in QCD

abstract:
  We study the spatial correlator of the topological charge density operator in
pure SU(3) gauge theory and in two flavor QCD. We show that the data for
distances up to about 1 fm is consistent with a vacuum consisting of individual
instantons and closely bound pairs. The percentage of paired objects is twice
as large on the dynamical configurations than on the pure gauge ones, implying
increased molecule formations due to fermionic interactions.


title: Hamiltonian lattice QCD at finite chemical potential

abstract:
  At sufficiently high temperature and density, quantum chromodynamics (QCD) is
expected to undergo a phase transition from the confined phase to the
quark-gluon plasma phase. In the Lagrangian lattice formulation the Monte Carlo
method works well for QCD at finite temperature, however, it breaks down at
finite chemical potential. We develop a Hamiltonian approach to lattice QCD at
finite chemical potential and solve it in the case of free quarks and in the
strong coupling limit. At zero temperature, we calculate the vacuum energy,
chiral condensate, quark number density and its susceptibility, as well as mass
of the pseudoscalar, vector mesons and nucleon. We find that the chiral phase
transition is of first order, and the critical chemical potential is $\mu_C
=m_{dyn}^{(0)}$ (dynamical quark mass at $\mu=0$). This is consistent with
$\mu_C \approx M_N^{(0)}/3$ (where $M_N^{(0)}$ is the nucleon mass at $\mu=0$).


title:
Random Matrix Theory and Dirac Spectrum at Nonzero Temperature and
  Density

abstract:
  We investigate the eigenvalue spectrum of the staggered Dirac matrix in SU(3)
gauge theory and in full QCD as well as in quenched U(1) theory on various
lattice sizes. As a measure of the fluctuation properties of the eigenvalues,
we study the nearest-neighbor spacing distribution, $P(s)$. We further study
lattice QCD at nonzero chemical potential, $\mu$, by constructing the spacing
distribution of adjacent eigenvalues in the complex plane. We find that in all
regions of their phase diagrams, compact lattice gauge theories have bulk
spectral correlations given by random matrix theory, which is an indication for
quantum chaos.


title:
Locality bound for effective four-dimensional action of domain-wall
  fermion

abstract:
  We discuss locality in the domain-wall QCD through the effective
four-dimensional Dirac operator which is defined by the transfer matrix of the
five-dimensional Wilson fermion. We first derive an integral representation for
the effective operator, using the inverse five-dimensional Wilson-Dirac
operator with the anti-periodic boundary condition in the fifth direction.
Exponential bounds are obtained from it for gauge fields with small lattice
field strength.


title: Fake symmetry transitions in lattice Dirac spectra

abstract:
  In a recent lattice investigation of Ginsparg-Wilson-type Dirac operators in
the Schwinger model, it was found that the symmetry class of the random matrix
theory describing the small Dirac eigenvalues appeared to change from the
unitary to the symplectic case as a function of lattice size and coupling
constant. We present a natural explanation for this observation in the
framework of a random matrix model, showing that the apparent change is caused
by the onset of chiral symmetry restoration in a finite volume. A transition
from unitary to symplectic symmetry does not occur.


title: Chiral fermions on a finite lattice

abstract:
  We discuss how to formulate Dirac fermion operator on a finite lattice such
that it can provide a nonperturbative regularization for massless fermion
interacting with a background gauge field.


title: The PMS project: Poor Man's Supercomputer

abstract:
  We briefly describe the Poor Man's Supercomputer (PMS) project carried out at
Eotvos University, Budapest. The goal was to develop a cost effective,
scalable, fast parallel computer to perform numerical calculations of physical
problems that can be implemented on a lattice with nearest neighbour
interactions. To this end we developed the PMS architecture using PC components
and designed a special, low cost communication hardware and the driver software
for Linux OS. Our first implementation of PMS includes 32 nodes (PMS1). The
performance of PMS1 was tested by Lattice Gauge Theory simulations. Using SU(3)
pure gauge theory or bosonic MSSM on PMS1 we obtained 3$/Mflop and 0.45$Mflop
price-to-sustained performance for double and single precision operations,
respectively. The design of the special hardware and the communication driver
are freely available upon request for non-profit organizations.


title: A Two-Loop Four-Gluon Helicity Amplitude in QCD

abstract:
  We present the two-loop pure gauge contribution to the gluon-gluon scattering
amplitude with maximal helicity violation. Our construction of the amplitude
does not rely directly on Feynman diagrams, but instead uses its analytic
properties in 4 - 2 epsilon dimensions. We evaluate the loop integrals
appearing in the amplitude through O(epsilon^0) in terms of polylogarithms.


title:
Reconciling the Two-Loop Diagrammatic and Effective Field Theory
  Computations of the Mass of the Lightest CP-even Higgs Boson in the MSSM

abstract:
  The mass of the lightest CP-even Higgs boson of the minimal supersymmetric
extension of the Standard Model (MSSM) has previously been computed including
O(alpha alpha_s) two-loop contributions by an on-shell diagrammatic method,
while approximate analytic results have also been obtained via
renormalization-group-improved effective potential and effective field theory
techniques. Initial comparisons of the corresponding two-loop results revealed
an apparent discrepancy between terms that depend logarithmically on the
supersymmetry-breaking scale, and different dependences of the non-logarithmic
terms on the squark mixing parameter, X_t. In this paper, we determine the
origin of these differences as a consequence of different renormalization
schemes in which both calculations are performed. By re-expressing the on-shell
result in terms of MS-bar parameters, the logarithmic two-loop contributions
obtained by the different approaches are shown to coincide. The remaining
difference, arising from genuine non-logarithmic two-loop contributions, is
identified, and its effect on the maximal value of the lightest CP-even Higgs
boson mass is discussed. Finally, we show that in a simple analytic
approximation to the Higgs mass, the leading two-loop radiative corrections can
be absorbed to a large extent into an effective one-loop expression by
evaluating the running top quark mass at appropriately chosen energy scales.


title:
The Lifetimes of Heavy Flavour Hadrons - a Case Study in Quark-Hadron
  Duality

abstract:
  The status of heavy quark expansions for charm and beauty lifetime ratios is
reviewed. Taking note of the surprising semiquantitative success of this
description for charm hadrons I interprete the new data on $\tau (D_s)$ and
re-iterate the call for more precise measurements of $\tau (\Xi_c^{0,+})$ and
$\tau (\Omega_c)$. A slightly larger $B^-$ than $B_d$ lifetime is starting to
emerge as predicted; the largest lifetime difference in the beauty sector,
namely in $\tau (B_c)$ vs. $\tau (B)$ has correctly been predicted; the problem
posed by the short $\Lambda_b$ lifetime remains. The need for more accurate
data also on $\tau (B_s)$ and $\tau (\Xi_b^{-,0})$ is emphasized. I discuss
quark-hadron duality as the central theoretical issue at stake here.


title: Bose Symmetry Interference Effects of $4\pi$ Final States

abstract:
  We carefully analyze the relative branching ratios of $4\pi$ final states
$\pi^+\pi^-\pi^+\pi^-$, $\pi^+\pi^-\pi^0\pi^0$ and $\pi^0\pi^0\pi^0\pi^0$, from
various resonances of $J^{PC}=0^{++}$, $0^{-+}$, $2^{++}$. We find that the
Bose symmetry interference effects would make their ratios to obviously differ
from the naive counting values without considering these effects. The results
should be applied to estimate correctly various $4\pi$ decay branching ratios
of relevant resonances.


title: Re-Evaluation of the Elastic Scattering of Supersymmetric Dark Matter

abstract:
  We examine the cross sections for the elastic scattering of neutralinos
$\chi$ on nucleons $p,n$, as functions of $m_\chi$ in the constrained minimal
supersymmetric standard model. We find narrow bands of possible values of the
cross section, that are considerably lower than some previous estimates. The
constrained model is based on the minimal supergravity-inspired framework for
the MSSM, with universal scalar and gaugino masses $m_0, m_{1/2}$, and $\mu$
and the MSSM Higgs masses treated as dependent parameters. We explore
systematically the region of the $(m_{1/2}, m_0)$ plane where LEP and other
accelerator constraints are respected, and the relic neutralino density lies in
the range $0.1 \le \Omega_{\chi} h^2 \le 0.3$ preferred by cosmology. We update
previous discussions of both the spin-independent and -dependent scattering
matrix elements on protons and neutrons, using recent analyses of low-energy
hadron experiments.


title: Neutrino Masses and Lepton-Quark Symmetries

abstract:
  The recent discovery by SuperKamiokande of evidence for neutrino masses
requires the addition of at least seven new parameters to the Standard Model.
We discuss the general theoretical schemes which require their inclusion, and
point out how quark-lepton symmetries, either in the framework of Grand
Unification, or of string theories, can be used to determine them


title: Introduction to Neutrinos

abstract:
  We discuss current theoretical and experimental issues associated with the
recent SuperKamiokande discovery. We survey theoretical models for predictings
the new Standard Model parameters needed to explain this discovery, and point
out how quark-lepton symmetries, either in the framework of Grand Unification,
or of string theories, can be used to determine them.


title: Charmonium Production from the Secondary Collisions at LHC Energy

abstract:
  We consider the charmonium production in thermalized hadronic medium created
in ultrarelativistic heavy ion collisions at LHC energy.
  The calculations for the secondary $J/\psi$ and $\psi^,$ production by $D\bar
D$ annihilation are performed within a kinetic model taking into account the
space-time evolution of a longitudinally and transversely expanding medium. We
show that the secondary charmonium production appears almost entirely during
the mixed phase and it is very sensitive to the charmonium dissociation cross
section with co-moving hadrons. Within the most likely scenario for the
dissociation cross section of the $J/\psi$ mesons their regeneration in the
hadronic medium will be negligible. The secondary production of $\psi^,$ mesons
however, due to their large cross section above the threshold, can
substantially exceed the primary yield.


title: Neutrinos: Heralds of New Physics

abstract:
  The central role of neutrinos in the determination of fundamental
interactions is reviewed. The recent SuperKamiokande discovery of neutrino mass
gives an {\it aper\c cu} of physics at short distances, and tests theories of
flavor. Quark-lepton symmetries, derived from grand unification and/or string
theories, can help determine the standard model parameters in the neutrino
sector.


title: From Neutrino Masses to Proton Decay

abstract:
  Current theoretical and experimental issues are reviewed in the light of the
recent SuperKamiokande discovery. By using quark-lepton symmetries, derived
from Grand Unification and/or string theories, we show how to determine the
necessary neutrino parameters. In addition, the seesaw neutrino masses set the
scale for the proton decay operators by ``measuring'' the standard model
cut-off. The SuperKamiokande values suggest that proton decay is likely to be
observed early in the XXIst Century.


title:
Is $f_1(1420)$ the partner of $f_1(1285)$ in the $^3P_1$ $q\bar{q}$
  nonet?

abstract:
  Based on a $2\times 2$ mass matrix, the mixing angle of the axial vector
states $f_1(1420)$ and $f_1(1285)$ is determined to be $51.5^{\circ}$, and the
theoretical results about the decay and production of the two states are
presented. The theoretical results are in good agreement with the present
experimental results, which suggests that $f_1(1420)$ can be assigned as the
partner of $f_1(1285)$ in the $^3P_1$ $q\bar{q}$ nonet. We also suggest that
the existence of $f_1(1510)$ needs further experimental confirmation.


title: Electron - Proton Scattering as a Probe of Nucleon Structure

abstract:
  The problem of electron-proton scattering is handed over both the elastic and
inelastic scattering. Two models are presented in this sense. The first,
depends on the multi photon exchange ladder diagram, where the transition
matrix is expanded in multi steps form. The second model uses the multi
peripheral mechanism developed for the electromagnetic field. It allows the
particle production in the inelastic scattering processes. An iterative
procedure is found and inserted in a Monte Carlo program to reproduce the
differential cross section of the reaction. The comparison with the
experimental data shows bid fair in most cases.


title:
Unitarized Heavy Baryon Chiral Perturbation Theory and the $\Delta$
  Resonance in $\pi N $ Scattering

abstract:
  Based on the recent phenomenological analysis done by M. Mojzis, Eur. Phys.
Jour. {\bf C2} (1998) 182, of $\pi N $ scattering within the framework of Heavy
Baryon Chiral Perturbation Theory we predict, after a suitable unitarization of
the amplitude, the $\Delta$ resonance at $\sqrt{s} = M_\Delta = 1238
\er{22}{18}{\rm MeV} $ and with a width of $ \Gamma_\Delta = 150 \er{43}{31}
{\rm MeV} $ in excellent agreement with the experimental numbers. The error
bars reflect only the uncertainties in the low energy parameters as determined
from an extrapolation to threshold of experimental data. We also describe
satisfactorily, within errors, the phase shifts up to $\sqrt{s} \sim 1300 {\rm
MeV} $.


title: Test of T violation in neutral B decays

abstract:
  T violation should be tested independently of CP violation. Besides K system,
B meson decays provide another good place to study T violation. In the Standard
Model, T violation in $B^0 \rightleftharpoons \bar{B^0}$ oscillation is
expected to be small. The angular distribution of $B\to VV$ decay permits one
to extract the T-odd correlation. In the absence of final state interaction, T
violation in $B\to J/\psi(l^+ l^-) K^*(K_S\pi^0)$ decay can reach $4-7%$ via
$B^0-\bar{B^0}$ mixing.


title: Status of the MSW Solutions to the Solar Neutrino Problem

abstract:
  In this talk we present the results of an updated global analysis of
two-flavor MSW solutions to the solar neutrino problem in terms of conversions
of $\nu_e$ into active or sterile neutrinos including the the full data set
corresponding to the 825-day Super-Kamiokande data sample as well as to
Chlorine, GALLEX and SAGE experiments.


title: Rapidity gaps at HERA and the Tevatron from soft colour exchanges

abstract:
  Models based on soft colour exchanges to rearrange colour strings in the
final state provide a general framework for both diffractive and
non-diffractive events in ep and hadron-hadron collisions. We study two such
models and find that they can reproduce rapidity gap data from both HERA and
the Tevatron. We also discuss the influence of parton cascades and multiple
interactions on the results.


title: Radion Potential and Brane Dynamics

abstract:
  We examine the cosmology of the Randall-Sundrum model in a dynamic setting
where scalar fields are present in the bulk as well as the branes. This
generates a mechanism similar to that of Goldberger-Wise for radion
stabilization and the recovery of late-cosmology features in the branes. Due to
the induced radion dynamics, the inflating branes roll towards the minimum of
the radion potential, thereby exiting inflation and reheating the Universe. In
the slow roll part of the potential, the 'TeV' branes have maximum inflation
rate and energy as their coupling to the radion and bulk modes have minimum
suppresion. Hence, when rolling down the steep end of the potential towards the
stable point, the radion field (which appears as the inflaton of the effective
4D theory in the branes) decays very fast, reheats the Universe .This process
results decayin a decrease of brane's canonical vacuum energy $\Lambda_4$.
However, at the minimum of the potential $\Lambda_4$ is small but not
neccessarily zero and the fine-tuning issue remains .Density perturbation
constraints introduce an upper bound when the radion stabilizies. Due to the
large radion mass and strong suppression to the bulk modes, moduli problems and
bulk reheating do not occur. The reheat temperature and a sufficient number of
e-folding constraints for the brane-universe are also satisfied. The model
therefore recovers the radiation dominated FRW universe.


title: Muon Collider Physics at Very High Energies

abstract:
  Muon colliders might greatly extend the energy frontier of collider physics.
One can contemplate circular colliders with center-of-mass energies in excess
of 10 TeV. Some physics issues that might be relevant at such a machine are
discussed.


title: Neutralino Proton Cross Sections In Supergravity Models

abstract:
  The neutralino-proton cross section is examined for supergravity models with
R-parity invariance with universal and non-universal soft breaking. The region
of parameter space that dark matter detectors are currently (or will be
shortly) sensitive i.e. $(0.1-10)\times 10^{-6}$ pb, is examined. For universal
soft breaking (mSUGRA), detectors with sensitivity
$\sigma_{\tilde{\chi}_{1}^{0}-p} \geq 1 \times 10^{-6}$ pb will be able to
sample parts of the parameter space for $\tan \beta \stackrel{>}{\sim} 25$.
Current relic density bounds restrict $m_{\tilde{\chi}_{1}^{0}} \leq 120$ GeV
for the maximum cross sections, which is below where astronomical uncertainties
about the Milky Way are relevant. Nonuniversal soft breaking models can allow
much larger cross sections and can sample the parameter space for $\tan \beta
\stackrel{>}{\sim} 4$. In such models, $m_0$ can be quite large reducing the
tension between proton decay bounds and dark matter analysis. We note the
existance of two new domains where coannihilation effects can enter, i.e. for
mSUGRA at large $\tan \beta$, and for nonuniversal models with small $\tan
\beta$.


title: The Xi(2230) Meson and The Pomeron Trajectory

abstract:
  We examine the possibility that the xi(2230) meson is a member of the Pomeron
trajectory. A method of connecting the xi --> p pbar decay width and the pp
cross sections through the Pomeron residue function is presented. We have used
a relativistic, singularity-free form factor to make the analytic continuation
of the residue function between crossed channels. We predict that if the
xi(2230) meson is a Pomeron, then it should have a xi --> p pbar decay width of
about 2 MeV.


title:
Chiral-Odd Contribution to Single-Transverse Spin Asymmetry in Hadronic
  Pion Production

abstract:
  A formula for the single transverse spin asymmetry in the large-$p_T$ pion
production in the nucleon-nucleon collision is derived. We focuss on the
chiral-odd contribution where the transversity distribution and the chiral-odd
spin-independent twist-3 distribution contributes. This contribution is
expected to give rise to a large effect at $x_F\to -1$.


title: One-particle inclusive CP asymmetries

abstract:
  One-particle inclusive CP asymmetries in the decays of the type B -> D(*) X
are considered in the framework of a QCD based method to calculate the rates
for one-particle inclusive decays.


title:
A four-neutrino texture implying bimaximal flavor mixing and reduced
  LSND effect

abstract:
  A four-neutrino effective texture is described, where a sterile neutrino
mixes nearly maximally with the electron neutrino and so, is responsible for
the deficit of solar $\nu_e $'s (according to the large-angle MSW solution or
vacuum solution, of which the former is selected a posteriori). But, while
maximal mixing of muon neutrino with tauon neutrino causes the deficit of
atmospheric $\nu_\mu $'s, the original magnitude of LSND effect is reduced by
as much as four orders, becoming unobservable.


title: Neutrino Masses and Grand Unification

abstract:
  We discuss some models of neutrino masses and mixings in the context of
fermion masses in Grand Unified Theories.


title: Signatures of massive sgoldstinos at e+e- colliders

abstract:
  In supersymmetric extensions of the Standard Model with a very light
gravitino, the effective theory at the weak scale should contain not only the
goldstino G, but also its supersymmetric partners, the sgoldstinos. In the
simplest case, the goldstino is a gauge-singlet and its superpartners are two
neutral spin-0 particles, S and P. We study possible signals of massive
sgoldstinos at e+e- colliders, focusing on those that are most relevant at LEP
energies. We show that the LEP constraints on e+e- => photon+S (photon+P), Z+S
(Z+P) or e+e-S (e+e-P), followed by S (P) decaying into two gluon jets, can
lead to stringent combined bounds on the gravitino and sgoldstino masses.


title: Making Baryons Below the Electroweak Scale

abstract:
  I describe a new way for baryogenesis to proceed, which evades many of the
problems of GUT and electroweak scenarios. If the reheat temperature after
inflation is below the electroweak scale, neither GUT baryon production nor
traditional electroweak baryogenesis can occur. However, non-thermal production
of sphaleron configurations via preheating could generate the observed baryon
asymmetry of the universe. Such low scale baryon production is particularly
attractive since it evades a number of strong constraints on reheating from
gravitino and moduli production.


title: Atmospheric Neutrino Flux: A Review of Calculations

abstract:
  Interpretation and understanding of the evidence for neutrino oscillations
depends on knowledge of the atmospheric neutrino beam. In this talk I assess
how well various features are known. The goal is to determine to what extent
uncertainties in the neutrino beam may limit the conclusions about neutrino
properties and which features of the evidence for neutrino oscillations are
most robust.


title: On the Resummed Hadronic Spectra of Inclusive B Decays

abstract:
  In this paper we investigate the hadronic mass spectra of inclusive B decays.
Specifically, we study how an upper cut on the invariant mass spectrum, which
is necessary to extract V_{ub}, results in the breakdown of the standard
perturbative expansion due to the existence of large infrared logs. We first
show how the decay rate factorizes at the level of the double differential
distribution. Then, we present closed form expressions for the resummed cut
rate for the inclusive decays B -> X_s gamma and B -> X_u e nu at
next-to-leading order in the infrared logs. Using these results, we determine
the range of cuts for which resummation is necessary, as well as the range for
which the resummed expansion itself breaks down. We also use our results to
extract the leading and next to leading infrared log contribution to the two
loop differential rate. We find that for the phenomenologically interesting cut
values, there is only a small region where the calculation is under control.
Furthermore, the size of this region is sensitive to the parameter
\bar{\Lambda}. We discuss the viability of extracting V_{ub} from the hadronic
mass spectrum.


title: CP Violation and Rare Decays

abstract:
  After a brief essay on the current state of particle physics and possible
approaches to the opportunities before us, I summarize the contributions to the
Third Workshop on Physics and Detectors for DAFNE that deal with CP Violation
and Rare Decays.


title:
Probing Intermediate Mass Higgs Interactions at the CERN Large Hadron
  Collider

abstract:
  We analyze the potentiality of the CERN Large Hadron Collider to probe the
Higgs boson couplings to the electroweak gauge bosons. We parametrize the
possible deviations of these couplings due to new physics in a model
independent way, using the most general dimension--six effective lagrangian
where the SU(2)_L x U(1)_Y is realized linearly. For intermediate Higgs masses,
the decay channel into two photons is the most important one for Higgs searches
at the LHC. We study the effects of these new interactions on the Higgs
production mechanism and its subsequent decay into two photons. We show that
the LHC will be sensitive to new physics scales beyond the present limits
extracted from the LEP and Tevatron physics.


title:
Extra dimensions and Strong Neutrino-Nucleon interactions above
  $10^{19}$ eV : Breaking the GZK Barrier

abstract:
  Cosmic ray events above $10^{20}$ eV are on the verge of confronting
fundamental particle physics. The neutrino is the only candidate primary among
established particles capable of crossing 100 Mpc intergalactic distances
unimpeded. The magnitude of $\nu N$ cross sections indicated by events, plus
consistency with the Standard Model at low-energy, point to new physics of
massive spin-2 exchange. In models based on extra dimensions, we find that the
$\nu N$ cross section rises to typical hadronic values of between 1 and 100 mb
at energies above $10^{20}$ eV. Our calculations take into account constraints
of unitarity. We conclude that air-showers observed with energies above
$10^{19}$ eV are consistent with neutrino primaries and extra-dimension models.
An {\it upper bound} of 1-10 TeV on the mass scale at which graviton exchange
becomes strong in current Kaluza-Klein models follows.


title: Recent Progress in PYTHIA

abstract:
  PYTHIA is a general-purpose event generator for multiparticle production in
high-energy physics. After a general introduction and program news survey, some
areas of recent physics progress are considered: the matching to matrix
elements, especially for W/Z production; charm and bottom hadronization;
multiple interactions; and interconnection effects. The report concludes with
some words on the future, specifically the ongoing transition to C++.


title: Light Stop: MSSM versus R-parity violation

abstract:
  We discuss the phenomenology of the lightest stops in models where R-parity
is broken by bilinear terms. In this class of models we consider scenarios
where the R-parity breaking two-body decay stop_1 -> tau + b competes with the
leading three-body decays stop_1 -> W^+ + b + neutralino_1, H^+ + b +
neutralino_1, b slepton^+_i neutrino_l, b sneutrino_l l^+ (l=e, mu, tau). We
demonstrate that the R-parity violating decay can be the dominant one. In
particular we focus on the implications for a future electron posistion Linear
Collider.


title:
Possible Test of the GUT Relation between $M_1$ and $M_2$ in
  Electron-Photon Scattering

abstract:
  We investigate associated production of selectrons and the lightest
neutralino (LSP) in the process e^- + gamma --> neutralino_1 + selectron_{L/R}
with the selectron subsequently decaying into an electron and the LSP. Total
cross sections and various polarization asymmetries are calculated for photons
produced by Compton backscattering of a polarized laser beam at an $e^+e^-$
linear collider with CMS energy $\sqrt{s_{ee}}=500$ GeV and with polarized
beams. The total cross section and in particular the polarization asymmetries
show a characteristic dependence on the gaugino mass parameter $M_1$. Therefore
this process is suitable for testing the GUT relation
$M_1=M_2\cdot{5/3}\tan^2\theta_W $.


title: Gamma(*)Gamma(*) reaction at high energies

abstract:
  The energy available for gamma(*)gamma(*) physics at LEP2 is opening a new
window on the study of diffractive phenomena, both non-perturbative and
perturbative. We discuss some of the uncertainties and problems connected with
the experimental measurements and their interpretation.


title: The Case for Neutrino Oscillations

abstract:
  No abstract appeared in the Proceedings, but I am adding the following
summary at the request of the X^3 people: The idea of neutrino masses is
discussed in the context of grand unified theories., and various scenarios are
presented, including the seesaw mechanism. At the end, preference is stated for
maximal mixing between $\nu_\mu$ and $\nu_\tau$, and small mixing with $\nu_e$.


title: The $K_L\to\pi^0\nu\bar\nu$ Decay in Models of Extended Scalar Sector

abstract:
  We calculate new contributions to the $K_L\to\pi^0\nu\bar\nu$ decay in models
where neutrino Majorana masses require an extension of the scalar sector.
First, we study a model where the neutrino mass is induced by the vacuum
expectation value of an SU(2)-triplet scalar. Second, we study the Zee model
where the Majorana mass comes from one loop diagrams involving a singly
charged, SU(2)-singlet scalar. In both models, the Yukawa couplings that
involve the new scalar and the neutrinos could be of order one. We find,
however, that the contributions to the $K_L\to\pi^0\nu\bar\nu$ decay mediated
by the new scalars depend on the neutrino masses rather than the Yukawa
couplings and are, therefore, negligibly small.


title: Gribov's Equation for the Green Function of Light Quarks

abstract:
  Gribov's scenario of supercritical charges in QCD is investigated. We perform
a numerical study of the corresponding equation for the Green function of light
quarks. This is done in an approximation which neglects all pion contributions.
Different types of solutions in the Euclidean region are discussed and the mass
function of the quark is calculated. The solutions of the equation are shown to
have a qualitatively different behaviour if the strong coupling constant
alpha_s exceeds a critical value alpha_c = 0.43 in the infrared region. Chiral
symmetry breaking is found to occur at supercritical coupling. The analytic
structure of the solutions is investigated. Earlier results obtained by Gribov
are confirmed and extended.


title: Supernova Bounds on Majoron-emitting decays of light neutrinos

abstract:
  Neutrino masses arising from the spontaneous violation of ungauged
lepton-number are accompanied by a physical Goldstone boson, generically called
Majoron. In the high-density supernova medium the effects of Majoron-emitting
neutrino decays are important even if they are suppressed in vacuo by small
neutrino masses and/or small off-diagonal couplings. We reconsider the
influence of these decays on the neutrino signal of supernovae in the light of
recent Super-Kamiokande data on solar and atmospheric neutrinos. We find that
majoron-neutrino coupling constants in the range $3\times 10^{-7}\lsim g\lsim
2\times 10^{-5}$ or $g \gsim 3 \times 10^{-4}$ are excluded by the observation
of SN1987A. Then we discuss the potential of Superkamiokande and the Sudbury
Neutrino Observatory to detect majoron neutrino interactions in the case of a
future galactic supernova. We find that these experiments could probe majoron
neutrino interactions with improved sensitivity.


title:
Subtraction method for NLO corrections in Monte-Carlo event generators
  for leptoproduction

abstract:
  In the case of the gluon-fusion process in deep-inelastic leptoproduction, I
explicitly show how to incorporate NLO corrections in a Monte-Carlo event
generator by a subtraction method. I calculate the parton densities to be used
by the event generator in terms of MSbar densities. The method is
generalizable. A particular motivation for treating the gluon-fusion process is
to treat diffractive deep-inelastic scattering properly, since in diffractive
scattering the gluon density dominates the quark densities. I also propose a
modified algorithm for treating parton kinematics in event generators; the new
algorithm results in much simpler formulae for the NLO corrections. A
disadvantage of the new method is that some of the generated events may have
negative weights. However, an adjustable cut-off function is present in the
formalism, and this permits a renormalization-group-like transformation that
can be used to at least reduce the proportion of events with negative weights.


title: Seesaw mechanism and the neutrino mass matrix

abstract:
  The seesaw mechanism of neutrino mass generation is analysed under the
following assumptions: (1) minimal seesaw with no Higgs triplets, (2)
hierarchical Dirac masses of neutrinos, (3) large lepton mixing primarily or
solely due to the mixing in the right-handed neutrino sector, and (4) unrelated
Dirac and Majorana sectors of neutrino masses. It is shown that large mixing
governing the dominant channel of the atmospheric neutrino oscillations can be
naturally obtained and that this constrained seesaw mechanism favours the
normal mass hierarchy for the light neutrinos leading to a small $U_{e3}$ entry
of the lepton mixing matrix and a mass scale of the lightest right handed
neutrino $M\simeq 10^{10} - 10^{11}$ GeV. Any of the three main neutrino
oscillation solutions to the solar neutrino problem can be accommodated. The
inverted mass hierarchy and quasi-degeneracy of neutrinos are disfavoured in
our scheme.


title: Non-leptonic hyperon weak decays in the Skyrme model revisited

abstract:
  Non-leptonic hyperon weak decays are investigated in the SU(3) Skyrme model.
We use a collective coordinate scheme, following the approach in which the
symmetry breaking terms in the strong effective action are diagonalized
exactly. To describe the weak interactions we use an octet dominated weak
effective lagrangian that leads to a good description of the known 2\pi and
3\pi kaon decays. We show that the observed S-wave decays are reasonably well
reproduced in the model. On the other hand, our calculated P-wave amplitudes do
not agree with the empirical ones even though both pole and contact
contributions to these amplitudes are properly taken into account. Finally, an
estimate of the non-octet contributions to the decay amplitudes is presented.


title: Phases of Chiral Gauge Theories

abstract:
  We discuss the behavior of two non-supersymmetric chiral SU(N) gauge
theories, involving fermions in the symmetric and antisymmetric two-index
tensor representations respectively. In addition to global anomaly matching, we
employ a recently proposed inequality constraint on the number of effective low
energy (massless) degrees of freedom of a theory, based on the thermodynamic
free energy. Several possible zero temperature phases are consistent with the
constraints. A simple picture for the phase structure emerges if these theories
choose the phase, consistent with global anomaly matching, that minimizes the
massless degree of freedom count defined through the free energy. This idea
suggests that confinement with the preservation of the global symmetries
through the formation of massless composite fermions is in general not
preferred. While our discussion is restricted mainly to bilinear condensate
formation, higher dimensional condensates are considered for one case. We
conclude by commenting briefly on two related supersymmetric chiral theories.


title: The MSSM at present and future colliders

abstract:
  A brief overview over the phenomenology of the MSSM at present and future
colliders is given. The complementarity of indirect tests of the model via
precision observables and of the information from the direct production of SUSY
particles is emphasized. If the lightest Higgs boson of the MSSM will be
detected, its mass will also play an important role as a precision observable.


title:
Pion dispersion relation at finite temperature in the linear sigma model
  from chiral Ward identities

abstract:
  We develop one-loop effective vertices and propagators in the linear sigma
model at finite temperature satisfying the chiral Ward identities. We use these
in turn to compute the pion dispersion relation in a pion medium for small
momentum and temperatures on the order of the pion mass at next to leading
order in the parameter m_pi^2/4pi^2f_pi^2 and to zeroth order in the parameter
(m_pi/m_sigma)^2. We show that this expansion reproduces the result obtained
from chiral perturbation theory at leading order. The main effect is a
perturbative, temperature-dependent increase of the pion mass. We find no
qualitative changes in the pion dispersion curve with respect to the leading
order behavior in this kinematical regime.


title: Polarized Parton Distribution Functions in the Nucleon

abstract:
  Polarized parton distribution functions are determined by using world data
from the longitudinally polarized deep inelastic scattering experiments. A new
parametrization of the parton distribution functions is adopted by taking into
account the positivity and the counting rule. From the fit to the asymmetry
data A_1, the polarized distribution functions of u and d valence quarks, sea
quarks, and gluon are obtained. The results indicate that the quark spin
content is \Delta\Sigma=0.20 and 0.05 in the leading order (LO) and the
next-to-leading-order (NLO) MS-bar scheme, respectively. However, if x
dependence of the sea-quark distribution is fixed at small x by "perturbative
QCD" and Regge theory, it becomes \Delta \Sigma=0.24 ~ 0.28 in the NLO. The
small-x behavior cannot be uniquely determined by the existing data, which
indicates the importance of future experiments. From our analysis, we propose
one set of LO distributions and two sets of NLO ones as the
longitudinally-polarized parton distribution functions.


title: High-energy elastic hadron collisions and space structure of hadrons

abstract:
  The elastic and inelastic profiles have been derived from the measured
elastic differential cross section data with the help of exact impact parameter
representation of elastic scattering amplitude. The results obtained for $pp$
scattering at energy of 53 GeV and $\bar{p} p$ scattering at energy of 541 GeV
have been presented. They indicate that nucleons can be regarded as objects
characterized by a small core (diameter $\sim$ 0.4$\div$0.8 fm) and a half
transparent outer shell (responsible mainly for elastic hadron scattering).


title:
Probe of the Wtb coupling in $t \bar t$ pair production at Linear
  Colliders

abstract:
  The Wtb vertex can be probed on future colliders in the processes of single
top production (LHC, pp mode, NLC, $\gamma e$ mode) and of top pair production
(NLC, e^+ e^- mode). We analyse observables sensitive to anomalous Wtb
couplings in the top pair production process of e^+ e^- collisions. In
particular, forward-backward and spin-spin asymmetries of the top decay
products and the asymmetry of the lepton energy spectum are considered.
Possible bounds on anomalous couplings obtained are competitive to those
expected from the upgraded Tevatron and LHC. The validity of the infinitely
small width approximation for the three-body top decay is also studied in
detail.


title: Cosmic rays and neutrino interactions beyond the standard model

abstract:
  Some solutions of the hierarchy problem of particle physics can lead to
significantly increased neutrino cross sections beyond the electroweak scale.
We discuss some consequences for and constraints resulting from cosmic ray
physics.


title: The colour dipole approach to small-x processes

abstract:
  We explain why it is possible to formulate a wide variety of high energy
(small-x) photon-proton processes in terms of a universal dipole cross section
and compare and contrast various parameterizations of this function that exist
in the literature.


title:
Power Corrections to Event Shape Variables measured in ep Deep-Inelastic
  Scattering

abstract:
  Deep-inelastic ep scattering data, taken with the H1 detector at HERA, are
used to study event shape variables over a large range of "relevant energy" Q
between 7 GeV and 100 GeV. Previously published analysis on thrust, jet
broadening, jet mass and C parameter are substantially refined and updated;
differential two-jet rates treated as event shapes are presented for the first
time.
  The Q dependence of the mean values is fit to second order calculations of
perturbative QCD applying power law corrections proportional to 1/Q^p to
account for hadronization effects. The concept of these power corrections is
tested by a systematic investigation in terms of a non-perturbative parameter
\bar{alpha}_{p-1} and the strong coupling constant.


title: SO(10) and Large nu_mu - nu_tau Mixing

abstract:
  A general approach to understanding the large mixing seen in atmospheric
neutrinos is explained, as well as a highly predictive SO(10) model which
implements this approach. It is also seen how bimaximal mixing naturally arises
in this scheme. (Talk presented at NNN99, SUNY Stony Brook, Sept. 22-26, 1999)


title:
Possible Studies of Parton Distributions at JHF: polarized pd Drell-Yan
  process

abstract:
  We discuss possible studies of parton distributions at the proposed 50-GeV PS
facility. First, comments are given in general on the importance of large-x
physics for finding new physics. Second, polarized deuteron reactions are
discussed in connection with new structure functions which are specific for a
spin-1 hadron. Third, if the polarized proton-deuteron Drell-Yan process is
studied at the facility, it could provide information on the light-antiquark
flavor asymmetry in the polarized distributions.


title: Diffraction and the Pomeron

abstract:
  Recent experimental results on inclusive diffractive scattering and on
exclusive vector meson production are reviewed. The dynamical picture of hard
diffraction emerging in perturbative QCD is highlighted.


title:
Large Yukawa coupling corrections to scalar quark pair production in
  $e^+e^-$ annihilation

abstract:
  We calculate the large Yukawa coupling corrections to the top and bottom
scalar quark pair production in $\ee$ annihilation within the Minimal
Supersymmetric Standard Model. We include the vertex corrections and the
corrections to the gauge boson propagator enhanced by large masses. We find the
total corrections are quite significant. In some regions of the parameter space
the corrections are larger than 10%.


title: Vacuum Alignment in Technicolor Theories-I. The Technifermion Sector

abstract:
  We have carried out numerical studies of vacuum alignment in technicolor
models of electroweak and flavor symmetry breaking. The goal is to understand
alignment's implications for strong and weak CP nonconservation in quark
interactions. In this first part, we restrict our attention to the
technifermion sector of simple models. We find several interesting phenomena,
including (1) the possibility that all observable phases in the technifermions'
unitary vacuum-alignment matrix are integer multiples of \pi/N' where N' \le N,
the number of technifermion doublets, and (2) the possibility of exceptionally
light pseudoGoldstone technipions.


title: Weak decays Xi_Q -> Lambda_Q pi

abstract:
  The weak decays Xi_b -> Lambda_b pi and Xi_c -> Lambda_c pi, in which the
heavy quark is not destroyed, are discussed. The branching fractions for these
decays, corresponding to an absolute rate of order 0.01 ps^{-1}, should be at a
one percent level for the b hyperons and at a (few) per mill level for Xi_c,
possibly making feasible their experimental study in future. It is shown,
through an application of the heavy quark limit, the flavor SU(3) symmetry, and
PCAC, that the Delta I = 1/2 rule should hold very well in these decays, and
also that the Xi_b decays are purely S wave in the symmetry limit, while the
difference between the $S$ wave amplitudes of the Xi_c decays and those for the
Xi_b is related, in terms of the heavy quark expansion, to the difference of
the total decay rates within the (Xi_c, Lambda_c) triplet of charmed hyperons.
We also comment on the amplitudes of the semileptonic transitions Xi_Q ->
Lambda_Q l nu and on the weak radiative decays Xi_Q -> Lambda_Q gamma.


title: Baryon number non-conservation and phase transitions at preheating

abstract:
  Certain inflation models undergo pre-heating, in which inflaton oscillations
can drive parametric resonance instabilities. We discuss several phenomena
stemming from such instabilities, especially in weak-scale models; generically,
these involve energizing a resonant system so that it can evade tunneling by
crossing barriers classically. One possibility is a spontaneous change of phase
from a lower-energy vacuum state to one of higher energy, as exemplified by an
asymmetric double-well potential with different masses in each well. If the
lower well is in resonance with oscillations of the potential, a system can be
driven resonantly to the upper well and stay there (except for tunneling) if
the upper well is not resonant. Another example occurs in hybrid inflation
models where the Higgs field is resonant; the Higgs oscillations can be
transferred to electroweak (EW) gauge potentials, leading to rapid transitions
over sphaleron barriers and consequent B+L violation. Given an appropriate
CP-violating seed, we find that preheating can drive a time-varying condensate
of Chern-Simons number over large spatial scales; this condensate evolves by
oscillation as well as decay into modes with shorter spatial gradients,
eventually ending up as a condensate of sphalerons. We study these examples
numerically and to some extent analytically. The emphasis in the present paper
is on the generic mechanisms, and not on specific preheating models; these will
be discussed in a later paper.


title:
Effects Of Kaluza-Klein Excited W On Single Top Quark Production At
  Tevatron

abstract:
  In extra dimension theories if the gauge bosons of the standard model
propagate in the bulk of the extra dimensions then they will have Kaluza-Klein
excitations that can couple to the standard model fermions. In this paper we
study the effects of the first excited Kaluza-Klein mode of the W on single top
production at the Tevatron. We find that the cross section for the single top
production can be significantly reduced if the mass of the first Kaluza-Klein
excited $W \sim 1$ TeV. Hence, a measurement of the single top production cross
section smaller than the standard model prediction would not necessarily imply
$V_{tb} <1$ or evidence of extra generation(s) of fermions mixed with the third
generation.


title: Lattice simulations of the strange quark mass and Fritzsch texture

abstract:
  A number of numerical simulations of lattice gauge theory have indicated a
low mass of strange quark in 100 MeV range at the scale of $\mu=2$ GeV. In the
unquenched case, which is improved over the simulation in the quenched
approximation by the inclusion of $u$ and $d$ sea quark effects, one sees a
further downward trend. Here the fermion mass spectrum of the Fritzsch texture
is recalculated. In a single step supersymmetric GUT with $M_X \sim 10^{16}$
GeV such values of the strange quark mass can be obtained for low values of
$\tan \beta$. Experimental numbers $m^{pole}_t = 173 \pm 6$ GeV and $4.1 <
m_b(m_b) < 4.4$ GeV are used in this study. Since the scenario is
supersymmetric, gaugino loop diagrams contribute to the masses in addition to
usual tree level Yukawa contributions. Upper bound of the mixing parameter
$V_{cb}$ is taken at 0.045


title: A note on low scale unification and gamma-gamma scattering

abstract:
  In this note we study an interesting effect of low energy gravity on
photon-photon scattering at high energies.


title: Quarkonium momentum distributions in photoproduction and B decay

abstract:
  According to our present understanding many $J/\psi$ production processes
proceed through a coloured $c\bar{c}$ state followed by the emission of soft
particles in the quarkonium rest frame. The kinematic effect of soft particle
emission is usually a higher-order effect in the non-relativistic expansion,
but becomes important near the kinematic endpoint of quarkonium energy
(momentum) distributions. In an intermediate region a systematic resummation of
the non-relativistic expansion leads to the introduction of so-called `shape
functions'. In this paper we provide an implementation of the kinematic effect
of soft gluon emission which is consistent with the non-relativistic shape
function formalism in the region where it is applicable and which models the
extreme endpoint region. We then apply the model to photoproduction of $J/\psi$
and $J/\psi$ production in $B$ meson decay. A satisfactory description of $B$
decay data is obtained. For inelastic charmonium photoproduction we conclude
that a sensible comparison of theory with data requires a transverse momentum
cut larger than the currently used 1 GeV.


title:
A proposal on the search for the hybrid with $I^G(J^{PC})=1^-(1^{-+})$
  in the process $J/\psi\to\rho\omega\pi\pi$ at upgraded BEPC/BES

abstract:
  The moment expressions for the boson resonances X with spin-parity 0++, 1-+,
1++, and 2++ possibly produced in the process $J/\psi\to\rho X$, $X\to
b_1(1235)\pi$, $b_1\to \omega \pi$ are given in terms of the generalized moment
analysis method. The 1-+ resonance can be distinguished from other resonances
by means of these moments except for some rather special cases. The suggestion
that the search for the 1-+ hybrid can be performed in the above decay channel
at upgraded BEPC/BES is presented.


title:
Contribution of the direct decay $\phi\to\pi^+ \pi^- \gamma$ to the
  process $e^+ e^- \to \pi^+ \pi^- \gamma$ at DA$\Phi$NE

abstract:
  The potential of DAPHNE to explore direct radiative decay $\phi \to \pi^+
\pi^- \gamma$ is studied in detail. Predictions of different theoretical models
for this decay are compared. We find that it should be possible to discriminate
between these models at DAPHNE in one year, even assuming a relatively low
luminosity ${\cal{L}} = 10^{31} {\rm cm}^{-2} {\rm sec^{-1}}$. The influence of
the decay $\phi \to \pi^+ \pi^- \gamma$ on the measurement of total cross
section $\sigma(e^+e^- \to {\rm hadrons})$ by tagging a photon in the reaction
$e^+e^- \to \pi^+\pi^- \gamma$ is also discussed.


title: Electroweak physics in six-fermion final states at future e+e- colliders

abstract:
  Three studies on six-fermion production processes are presented, in which the
production of an intermediate-mass Higgs boson, the top-quark physics and the
analysis of possible anomalous quartic gauge couplings are considered. A Monte
Carlo event generator has been developed for full electroweak tree-level
calculations on six-fermion processes at the Linear Collider. The Monte Carlo
procedure has been adapted to deal with a large variety of diagram topologies,
so as to keep under control the relevant signals and all the backgrounds of
such processes. The effects of initial-state-radiation and beamstrahlung are
also taken into account. The relevance of electroweak backgrounds and
finite-width effects is discussed and several analyses of final-state
distributions are presented, both for the detection of the signals of interest
and for the study of properties of the particles involved, thus showing the
importance of complete calculations for precision studies at the Linear
Collider.


title: Hadronic Physics

abstract:
  I review the novel results and developments presented at the Third Workshop
on Physics and Detectors for DA$\Phi$NE that deal with hadronic physics. Topics
discussed include: the scalar quark condensate, kaon decays, the sector of
scalar and vector mesons, kaon-nucleon scattering, pion- and kaon-nucleon sigma
terms, and strange nuclear physics.


title: Electromagnetic properties of a neutrino stream

abstract:
  In a medium that contains a neutrino background in addition to the matter
particles, the neutrinos contribute to the photon self-energy as a result of
the effective electromagnetic vertex that they acquire in the presence of
matter. We calculate the contribution to the photon self-energy in a dense
plasma, due to the presence of a gas of charged particles, or neutrinos, that
moves as a whole relative to the plasma. General formulas for the transverse
and longitudinal components of the photon polarization tensor are obtained in
terms of the momentum distribution functions of the particles in the medium,
and explicit results are given for various limiting cases of practical
interest. The formulas are used to study the electromagnetic properties of a
plasma that contains a beam of neutrinos. The transverse and longitudinal
photon dispersion relations are studied in some detail. Our results do not
support the idea that neutrino streaming instabilities can develop in such a
system. We also indicate how the phenomenon of optical activity of the neutrino
gas is modified due to the velocity of the neutrino background relative to the
plasma. The general approach and results can be adapted to similar problems
involving relativistic plasmas and high-temperature gauge theories in other
environments.


title:
Hadron spectroscopy based on relativistic Schr\"odinger-like wave
  equations

abstract:
  Relativistic potential-type equations are proposed which approximately
reproduce important features and constraints of field-theoretic models and can
be useful tool in hadron spectroscopy. Within this approach, the
Regge-trajectory parameters and some properties of hihger radial excitations in
the light quark sector are discussed.


title:
Matter effects on neutrino oscillations in gravitational and magnetic
  fields

abstract:
  When neutrinos propagate in a background, their gravitational couplings are
modified by their weak interactions with the particles in the background. In a
medium that contains electrons but no muons or taons, the matter-induced
gravitational couplings of neutrinos are different for the various neutrino
flavors, and they must be taken into account in describing the phenomena
associated with the neutrino oscillations in the presence of strong
gravitational fields. Here we incorporate those couplings in that description,
including also the effects of a magnetic field, and consider the implications
that they have for the emission of high energy neutrinos in the vicinity of
Active Galactic Nuclei.


title: Dark Matter at the Galactic Center

abstract:
  Particle dark matter near the galactic center is accreted by the central
black hole into a dense spike, strongly enhancing its annihilation rate.
Searching for its annihilation products may give us information on the presence
or absence of a central cusp in the dark halo profile. We summarize our paper
Phys Rev Lett 83, 1719 (1999), and use an updated limit on the neutrino
emission from the galactic center.


title: Effects of CP-Violation in Neutralino Scattering and Annihilation

abstract:
  We summarize our paper hep-ph/9908390, where we find that in some regions of
supersymmetric parameter space, CP violating effects that mix the CP-even and
CP-odd Higgs bosons can enhance the neutralino annihilation rate by factors of
10^6, and reduce the neutralino scattering rate off nucleons by factors of
10^{-7}.


title: Families as Neighbors in Extra Dimension

abstract:
  We propose a new mechanism for explanation of the fermion hierarchy without
introducing any family symmetries. Instead, we postulate that different
generations live on different branes embedded in a relatively large extra
dimension, where the gauge fields can propagate. The electroweak symmetry is
broken on a separate brane, which is a source of exponentially decaying Higgs
profile in the bulk. The resulting fermion masses and mixings are determined by
an exponentially suppressed overlap of the fermion and Higgs wave functions and
are automatically hierarchical even if all copies are identical and there is no
hierarchy of distances. In this framework the well known pattern of the
"nearest neighbor mixing" is predicted due to the fact that the families are
literally neighbors in the extra space. This picture may also provide a new way
of a hierarchically weak supersymmetry breaking, provided that the combination
of three family branes is a non-BPS configuration, although each of them,
individually taken, is. This results in exponentially weak supersymmetry
breaking. We also discuss the issue of embedding identical branes in the
compact spaces and localization of the fermionic zero modes.


title: Alternative Supersymmetric Spectra

abstract:
  We describe the features of supersymmetric spectra, alternative to and
qualitatively different from that of most versions of the MSSM. The spectra are
motivated by extensions of the MSSM with an extra U(1)' gauge symmetry,
expected in many grand unified and superstring models, which provide a
plausible solution to the mu problem, both for models with supergravity and for
gauge-mediated supersymmetry breaking. Typically, many or all of the squarks
are rather heavy (larger than one TeV), especially for the first two families,
as are the sleptons in the supergravity models. However, there is a richer
spectrum of Higgs particles, neutralinos, and (possibly) charginos. Concrete
examples of such spectra are presented, and the phenomenological implications
are briefly discussed.


title:
Discovery and Identifictation of Extra Gauge Bosons in e^+e^- -> nu
  nubar gamma

abstract:
  We examine the sensitivity of the process e+e- -> nu nubar gamma to extra
gauge bosons, Z' and W', which arise in various extensions of the standard
model. The process is found to be sensitive to W' masses up to several TeV,
depending on the model, the center of mass energy, and the assumed integrated
luminosity. If extra gauge bosons were discovered first in other experiments,
the process could also be used to measure Z' nu nubar and W' couplings. This
measurement would provide information that could be used to unravel the
underlying theory, complementary to measurements at the Large Hadron Collider.


title:
String formation and chiral symmetry breaking in the heavy-light
  quark-antiquark system in QCD

abstract:
  The effective quark Lagrangian is written for a light quark in the field of a
static antiquark, explicitly containing field correlators as coefficient
functions of products of quark operators. At large N_c the closed system of
equations for the gauge-invariant quark Green's function in the field of static
source is examined analytically. The formation of the string connecting the
light quark to the static source is observed numerically. The scalar Lorentz
nature of the resulting confinement is shown to hold for the considered case,
implying chiral symmetry breaking. The resulting spectrum with and without
perturbative gluon exchanges is obtained numerically and compared to the B and
D meson masses and HQET.


title: Flavor asymmetry in polarized proton-deuteron Drell-Yan process

abstract:
  We discuss the possibility of finding polarized antiquark flavor asymmetry in
Drell-Yan processes. We find that the difference between polarized
proton-proton and proton-deuteron Drell-Yan cross sections should provide
valuable information on the polarized flavor asymmetry. Numerical results
indicate that the asymmetry effects are conspicuous especially in the large-x_F
region. Our analysis is important for the transversity distributions because
the flavor asymmetry cannot be found by inclusive lepton scattering and
W-production processes.


title: Neutrino scattering in strong magnetic fields

abstract:
  We show that neutrino cross sections are direction dependent in a background
magnetic field.


title:
Drell-Yan proton-deuteron asymmetry and polarized light-antiquark
  distributions

abstract:
  We discuss the Drell-Yan proton-deuteron (p-d) asymmetry R_{pd}, which is
defined by the proton-proton and proton-deuteron cross-section ratio
\Delta_{(T)}\sigma^{pd}/2\Delta_{(T)}\sigma^{pp}, and its relation to the
polarized light-antiquark flavor asymmetry. Using a formalism of the polarized
{\it pd} Drell-Yan process, we show that the R_{pd} especially in the large-x_F
region is very useful for finding the flavor asymmetry in the
longitudinally-polarized and transversity distributions. Our results are
particularly important to study the flavor asymmetry in the transversity
distributions because they cannot be measured by inclusive deep inelastic
scattering and W-production process.


title: Are Kaluza-Klein modes enhanced by parametric resonance?

abstract:
  We study parametric amplification of Kaluza-Klein (KK) modes in a higher
$D$-dimensional generalized Kaluza-Klein theory, which was originally
considered by Mukohyama in the narrow resonance case. It was suggested that KK
modes can be enhanced by an oscillation of a scale of compactification by the
$d$-dimensional sphere $S^d~(d=D-4)$ and by the direct product $S^{d_1}\times
S^{d_2}~(d_1+d_2=D-4)$. We extend this past work to the more general case where
initial values of the scale of compactification and the quantum number of the
angular momentum $l$ of KK modes are not small. We perform analytic approaches
based on the Mathieu equation as well as numerical calculations, and find that
the expansion of the universe rapidly makes the KK field deviate from
instability bands. As a result, KK modes are not enhanced sufficiently in an
expanding universe in these two classes of models.


title: The Components of the $\gamma^*\gamma^*$ Cross Section

abstract:
  We extend our previous treatment of $\gamma^*p$ cross section based on
Gribov's hypothesis to the case of photon-photon scattering. With the aid of
two parameters, determined from experimental data, we separate the interactions
into two categories corresponding to short ("soft") and long ("hard") distance
processes. The photon-photon cross section, thus, receives contributions from
three sectors, soft-soft, hard-hard and hard-soft. The additive quark model is
used to describe the soft-soft sector, pQCD the hard-hard sector, while the
hard-soft sector is determined by relating it to the $\gamma^{*}$p system. We
calculate and display the behaviour of the total photon-photon cross section
and it's various components and polarizations for different values of energy
and virtuality of the two photons, and discuss the significance of our results.


title: Bose-Einstein Correlations in e+e- -> W+W- at a Linear Collider

abstract:
  We show that the most popular method to simulate Bose-Einstein (BE)
interference effects predicts negligible correlations between identical pions
originating from the hadronic decay of different W's produced in e+e- -> W+W-
-> 4 jets at typical linear collider energies.