title:
An Orientation Selective Neural Network and its Application to Cosmic
  Muon Identification

abstract:
  We propose a novel method for identification of a linear pattern of pixels on
a two-dimensional grid. Following principles employed by the visual cortex, we
employ orientation selective neurons in a neural network which performs this
task. The method is then applied to a sample of data collected with the ZEUS
detector at HERA in order to identify cosmic muons which leave a linear pattern
of signals in the segmented uranium-scintillator calorimeter. A two dimensional
representation of the relevant part of the detector is used. The results
compared with a visual scan point to a very satisfactory cosmic muon
identification. The algorithm performs well in the presence of noise and pixels
with limited efficiency. Given its architecture, this system becomes a good
candidate for fast pattern recognition in parallel processing devices.


title:
Elastic Electroproduction of $\rh0$ and $J/\Psi$ Mesons at large $Q^2$
  at HERA

abstract:
  The total cross sections for the elastic electroproduction of $\rh0$ and
$J/\Psi$ mesons for $Q^2$ $>$ 8 GeV$^2$ and $<W > \simeq 90$ GeV/c$^2$ are
measured at HERA with the H1 detector. The measurements are for an integrated
electron$-$proton luminosity of $\simeq$~3~pb$^{-1}$. The dependences of the
total virtual photon$-$proton ($\gamma^* p$) cross sections on $Q^2$, $W$ and
the momentum transfer squared to the proton ($t$), and, for the $\rho$, the
dependence on the polar decay angle ($\cos \theta^*$), are presented. The
$J/\Psi$ : $\rh0$ cross section ratio is determined. The results are discussed
in the light of theoretical models and of the interplay of hard and soft
physics processes.


title: Charm Lifetimes and Semileptonic Decays

abstract:
  This paper gives an experimental overview of current status and open
questions on charm lifetimes and semileptonic decays, the latter including new
results presented by E687 and CLEO at this Conference.


title: Review of hadronic and rare $B$ decays

abstract:
  We review recent results on rare and hadronic B decays from the CLEO, CDF and
LEP experiments.


title:
Measurement of the Diffractive Cross Section in Deep Inelastic
  Scattering

abstract:
  Diffractive scattering of $\gamma^* p \to X + N$, where $N$ is either a
proton or a nucleonic system with $M_N~<~4$~GeV has been measured in deep
inelastic scattering (DIS) at HERA. The cross section was determined by a novel
method as a function of the $\gamma^* p$ c.m. energy $W$ between 60 and 245~GeV
and of the mass $M_X$ of the system $X$ up to 15~GeV at average $Q^2$ values of
14 and 31~GeV$^2$. The diffractive cross section $d\sigma^{diff} /dM_X$ is,
within errors, found to rise linearly with $W$. Parameterizing the $W$
dependence by the form $d\sigma^{diff}/dM_X \propto
(W^2)^{(2\overline{\mbox{$\alpha_{_{I\hspace{-0.2em}P}}$}} -2)}$ the DIS data
yield for the pomeron trajectory
$\overline{\mbox{$\alpha_{_{I\hspace{-0.2em}P}}$}} = 1.23 \pm 0.02(stat) \pm
0.04 (syst)$ averaged over $t$ in the measured kinematic range assuming the
longitudinal photon contribution to be zero. This value for the pomeron
trajectory is substantially larger than
$\overline{\mbox{$\alpha_{_{I\hspace{-0.2em}P}}$}}$ extracted from soft
interactions. The value of $\overline{\mbox{$\alpha_{_{I\hspace{-0.2em}P}}$}}$
measured in this analysis suggests that a substantial part of the diffractive
DIS cross section originates from processes which can be described by
perturbative QCD. From the measured diffractive cross sections the diffractive
structure function of the proton $F^{D(3)}_2(\beta,Q^2,
\mbox{$x_{_{I\hspace{-0.2em}P}}$})$ has been determined, where $\beta$ is the
momentum fraction of the struck quark in the pomeron. The form $F^{D(3)}_2 =
constant \cdot (1/ \mbox{$x_{_{I\hspace{-0.2em}P}}$})^a$ gives a good fit to
the data in all $\beta$ and $Q^2$ intervals with $a = 1.46 \pm 0.04 (stat) \pm


title:
Search for Chargino-Neutralino Production in \ppb\sp Collisions at
  $\sqrt{s} = 1.8$ TeV

abstract:
  We have searched for chargino-neutralino production (\chichi) in 1.8 TeV
\ppb\sp collisions, followed by their leptonic decays
\chione\dk\chizero\lnu\psp and \chitwo\dk\chizero\lplm. These trilepton events
are expected within a framework of the Minimal Supersymmetric Standard Model
(MSSM). In a 19.1 pb$^{-1}$ data sample collected with the Collider Detector at
Fermilab, no trilepton events were observed. Upper limits on
$\sigma(\ppb\dk\chichi)\cdot BR(\chichi\dk 3 \ell + X)$ were obtained for
various MSSM parameter space regions, yielding new 95\% confidence level lower
limits for the neutralino (\chitwo) mass which extended as high as 49 \mgev.


title: Search for the Weak Decay of an H Dibaryon

abstract:
  We have searched for a neutral $H$ dibaryon decaying via $H\to\Lambda n$ and
$H\to\Sigma^0 n$. Our search has yielded two candidate events from which we set
an upper limit on the $H$ production cross section. Normalizing to the
inclusive $\Lambda$ production cross section, we find $(d\sigma_H/d\Omega) /
(d\sigma_\Lambda/d\Omega) < 6.3\times 10^{-6}$ at 90% C.L., for an $H$ of mass
$\approx$ 2.15 GeV/$c^2$.


title: Properties of Jets in Z Boson Events from 1.8 TeV $\bar{p}p$ Collisions

abstract:
  We present a study of events with Z bosons and hadronic jets produced in
$\bar{p}p$ collisions at a center-of-mass energy of 1.8 TeV. The data consist
of 6708 $Z \to e^+e^-$ decays from 106 pb$^{-1}$ of integrated luminosity
collected using the CDF detector at the Tevatron Collider. The Z $+ \ge n$ jet
cross sections and jet production properties have been measured for n = 1 to 4.
The data compare well to predictions of leading order QCD matrix element
calculations with added gluon radiation and simulated parton fragmentation.


title:
A Measurement and QCD Analysis of the Proton Structure Function
  $F_2(x,Q^2)$ at HERA

abstract:
  A new measurement of the proton structure function $F_2(x,Q^2)$ is reported
for momentum transfers squared $Q^2$ between 1.5 GeV$^2$ and 5000 GeV$^2$ and
for Bjorken $x$ between $3\cdot 10^{-5}$ and 0.32 using data collected by the
HERA experiment H1 in 1994. The data represent an increase in statistics by a
factor of ten with respect to the analysis of the 1993 data. Substantial
extension of the kinematic range towards low $Q^2$ and $x$ has been achieved
using dedicated data samples and events with initial state photon radiation.
The structure function is found to increase significantly with decreasing $x$,
even in the lowest accessible $Q^2$ region. The data are well described by a
Next to Leading Order QCD fit and the gluon density is extracted.


title: Elastic and Inelastic Photoproduction of \jpsi Mesons at HERA

abstract:
  Results on \jpsi production in $e p$ interactionsin the H1 experiment at HERA
are presented. The \jpsi mesons are produced by almost real photons
($Q^2\approx 0$) and detected via their leptonic decays. The data have been
taken in 1994 and correspond to an integrated luminosity of $2.7 {pb}^{-1}$.
The $\gamma p$ cross section for elastic \jpsi production is observed to
increase strongly with the \cm energy. The cross section for diffractive
$J/\psi$ production with proton dissociation is found to be of similar
magnitude as the elastic cross section. Distributions of transverse momentum
and decay angle are studied and found to be in accord with a diffractive
production mechanism. For inelastic \jpsi production the total $\gamma p$ cross
section, the distribution of transverse momenta, and the elasticity of the
\jpsi are compared to NLO QCD calculations in a colour singlet model and
agreement is found. Diffractive \psiprime production has been observed and a
first estimate of the ratio to \jpsi production in the HERA energy regime is
given.


title:
The Isolated Photon Cross Section in the Central and Forward Rapidity
  Regions in p-pbar Collisions at sqrt(s) = 1.8 TeV

abstract:
  A measurement of the cross section for production of single, isolated photons
is reported for transverse energies in the range of 10-125 GeV, for two regions
of pseudorapidity, |\eta|<0.9 and 1.6<|\eta|<2.5. The data represent 12.9 pb-1
of integrated luminosity accumulated in p-pbar collisions at sqrt{s} = 1.8 TeV
and recorded with the D0 detector at the Fermilab Tevatron Collider.


abstract:
  Particle Physics in International Collaboration. Talk given at Kolloquiumstag
``125 Jahre Teilchenphysik in Aachen", October 1995


title: Structure Function Measurement at HERA

abstract:
  Preliminary results on a measurement of the proton structure function F_2 are
reported for momentum transfers squared Q^2 between 1.5~GeV^2 and 5000 GeV^2
and for Bjorken x between 5.10^{-5} and 0.32 using data collected by the HERA
experiments H1 and ZEUS in 1994. F_2 increases significantly with decreasing x,
even in the lowest reachable Q^2 region. The data are well described by a Next
to Leading Order QCD fit, and support within the present precision that the
rise at low x within this Q^2 range is generated "radiatively" via the DGLAP
evolution equations. Prospects for future structure function measurements at
HERA are briefly mentioned.


title:
Measurement of the $Q^{2}$ dependence of the Charged and Neutral Current
  Cross Sections in $e^{\pm}p$ Scattering at HERA

abstract:
  The $Q^{2}$ dependence and the total cross sections for charged and neutral
current processes are measured in $e^{\pm}p$ reactions for transverse momenta
of the outgoing lepton larger than 25 GeV. Comparable size of cross sections
for the neutral current process and for the weak charged current process are
observed above $Q^2~\approx~5000$ GeV$^2$. Using the shape and magnitude of the
charged current cross section we determine a propagator mass of $m_{W} = 84\
^{+10}_{-7}$ GeV.


title: The Azimuthal Decorrelation of Jets Widely Separated in Rapidity

abstract:
  This study reports the first measurement of the azimuthal decorrelation
between jets with pseudorapidity separation up to five units. The data were
accumulated using the D{\O}detector during the 1992--1993 collider run of the
Fermilab Tevatron at $\sqrt{s}=$ 1.8 TeV. These results are compared to
next--to--leading order (NLO) QCD predictions and to two leading--log
approximations (LLA) where the leading--log terms are resummed to all orders in
$\alpha_{\scriptscriptstyle S}$. The final state jets as predicted by NLO QCD
show less azimuthal decorrelation than the data. The parton showering LLA Monte
Carlo {\small HERWIG} describes the data well; an analytical LLA prediction
based on BFKL resummation shows more decorrelation than the data.


title: Electroweak Physics Results from the DZero Detector at Fermilab

abstract:
  We present electroweak physics results from the DZero experiment using data
from collisions at \sqrt{s} = 1.8 TeV, concentrating on single W and Z
production cross sections and the production of electroweak gauge boson pairs.
The inclusive cross sections times branching ratios for W and Z production have
been measured and are used to determine the inclusive width of the W boson.
Direct tests of the WW\gamma and WWZ trilinear gauge boson couplings are
derived from the study of diboson production. These measurements test the
non-abelian self couplings of the W, Z and photon, one of the most direct
consequences of the SU(2)_L \times U(1)_Y gauge symmetry. We present
measurements of the WW\gamma coupling based on p pbar --> l \nu \gamma + X and
limits on anomalous WWZ and WW\gamma couplings based on searches for p \pbar
--> W^+ W^- + X --> l l' \nu \nubar + X and p \pbar --> WW / WZ + X --> e \nu +
jets + X. We also present limits on the ZZ\gamma and Z\gamma\gamma couplings
based on p pbar --> l^+ l^- \gamma + X events.


title: A Search for Light Super Symmetric Baryons

abstract:
  We have searched for the production and decay of light super-symmetric
baryons produced in 800 GeV/c proton copper interactions in a charged hyperon
beam experiment. We observe no evidence for the decays R+(uud \g^~) -> S(uds
\g^~) pi+ and X-(ssd \g^~) -> S(uds \g^~) pi- in the predicted parent mass and
lifetime ranges of 1700-2500 Mev/c2 and 50-500 ps. Production upper limits for
R+ at xF=0.47, Pt=1.4 GeV/c2 and X- at xF=0.48, Pt=0.65 GeV/c2 of less than
10^-3 of all charged secondary particles produced are obtained for all but the
highest masses and shortest lifetimes predicted.


title: Low Q^2 Structure Function Measurements

abstract:
  New Results on the measurement of the proton structure function F_2(x,Q^2)
are reported for momentum transfers squared Q^2 >= 1.5 GeV^2 and Bjorken x >=
3.5 10^{-5} using data collected by the HERA experiments H1 and ZEUS in 1994.
F_2 increases significantly with decreasing x, even in the lowest reachable Q^2
region. The data are well described by a Next to Leading Order QCD fit, and
support within the present precision that the rise at low x within this Q^2
range is generated via the DGLAP evolution equations. A comparison with models
based on pomeron exchange is also presented. The gluon density is extracted and
observed to rise at low x.


title: Measurement of Radiation Damage on Silica Aerogel \v Cerenkov Radiator

abstract:
  We measured the radiation damage on silica aerogel \v Cerenkov radiators
originally developed for the $B$-factory experiment at KEK. Refractive index of
the aerogel samples ranged from 1.012 to 1.028. The samples were irradiated up
to 9.8~MRad of equivalent dose. Measurements of transmittance and refractive
index were carried out and these samples were found to be radiation hard.
Deteriorations in transparency and changes of refractive index were observed to
be less than 1.3\% and 0.001 at 90\% confidence level, respectively. Prospects
of using aerogels under high-radiation environment are discussed.


title: Photoproduction of $D^{*\pm}$ Mesons in $ep$ Collisions at HERA

abstract:
  At the electron-proton collider HERA the inclusive $D^{*\pm}$ meson
photoproduction cross section has been measured with the H1 detector in two
different, but partly overlapping, kinematical regions. For the first, where
$<W_{\gamma p}> \approx 200$ GeV and $Q^2 < 0.01 \gev^2$, the result is
$\sigma(\gamma p \to c \bar{c} X) = (13.2 \pm 2.2 ^{+2.1}_{-1.7}
^{+9.9}_{-4.8}) \mu b$. The second measurement for $Q^2 < 4 \gev^2$ yields
$\sigma(\gamma p \to c \bar{c} X) = (9.3 \pm 2.1 ^{+1.9}_{-1.8} ^{+6.9}_
{-3.2}) \mu b$ at $<W_{\gamma p}> \approx 142$ GeV and $\sigma(\gamma p \to c
\bar{c} X) = (20.6 \pm 5.5 ^ {+4.3}_{-3.9} ^{+15.4}_{-7.2}) \mu b$ at
$<W_{\gamma p} > \approx 230$ GeV, respectively. The third error accounts for
an additional uncertainty due to the proton and photon parton density
parametrizations. Differential cross sections are presented as a function of
the $D^{*\pm}$ transverse momentum and rapidity. The results compare reasonably
well with next-to-leading order QCD calculations. Evidence for diffractive
photoproduction of charm quark is presented.


title: A Search for Squarks of Rp-Violating SUSY at HERA

abstract:
  A search for squarks of R-parity violating supersymmetry is performed in $ep$
collisions at HERA using H1 1994 $e^+$ data. Direct single production of
squarks of each generation by $e^+$-quark fusion via a Yukawa coupling
$\lambda'$ is considered. All possible R-parity violating decays and gauge
decays of the squarks are taken into account. No significant deviation from the
Standard Model predictions is found in the various multi-lepton and multi-jet
final states studied and exclusion limits are derived. At 95% confidence level,
the existence of first generation squarks is excluded for masses up to $240
\GeV $ for coupling values $\lambda' \gtrsim \sqrt{4\pi \alpha_{em}}$.The
limits obtained are shown to be only weakly dependent on the free parameters of
the Minimal Supersymmetric Standard Model. Stop squarks are excluded for masses
up to $138 \GeV$ for coupling $\lambda' \times \cos \theta_t$ to $e^+d$ pairs
$\gtrsim 0.1 \times \sqrt{4\pi \alpha_{em}}$, where $\theta_t$ is the mass
mixing angle. Light stop squarks are furthermore searched for through pair
production in $\gamma$-gluon fusion processes. No signal is observed and
exclusion limits are derived. Masses in the range 9 to $24.4 \GeV$ are excluded
at 95% confidence level for $\lambda' \times \cos \theta_t > 10^{-4}$.


title:
Mass Splitting and Production of $\Sigma_c^0$ and $\Sigma_c^{++}$
  Measured in $500 {GeV}$ $\pi^- -$N Interactions

abstract:
  From a sample of $2722 \pm 78$ $\Lambda_c^+$ decaying to the $pK^-\pi^+$
final state, we have observed, in the hadroproduction experiment E791 at
Fermilab, $143 \pm 20$ $\Sigma_c^0$ and $122 \pm 18$ $\Sigma_c^{++}$ through
their decays to $\Lambda_c^+ \pi^{\pm}$. The mass difference $M(\Sigma_c^0) -
M(\Lambda_c^+$) is measured to be $(167.38\pm 0.29\pm 0.15) {MeV}$; for
$M(\Sigma_c^{++}) - M(\Lambda_c^+)$, we find $(167.76\pm 0.29\pm0.15) {MeV}$.
The rate of $\Lambda_c^+$ production from decays of the $\Sigma_c$ triplet is
$(22\pm 2\pm 3) {%}$ of the total $\Lambda_c^+$ production assuming equal rate
of production from all three, as measured for $\Sigma_c^0$ and $\Sigma_c^{++}$.
We do not observe a statistically significant $\Sigma_c$ baryon-antibaryon
production asymmetry. The $x_F$ and $p_t^2$ spectra of $\Lambda_c^+$ from
$\Sigma_c$ decays are observed to be similar to those for all $\Lambda_c^+$'s
produced.


title:
Measurement of the Reaction $\gamma^* p \to \phi p$ in Deep Inelastic
  $e^+p$ Scattering at HERA

abstract:
  The production of $\phi$ mesons in the reaction $e^{+}p \rightarrow e^{+}
\phi p$ ($\phi \rightarrow K^{+}K^{-}$), for $7 < Q^2 < 25$ GeV$^2$ and for
virtual photon-proton centre of mass energies ($W$) in the range 42-134 GeV,
has been studied with the ZEUS detector at HERA. When compared to lower energy
data at similar $Q^2$, the results show that the $\gamma^*p \rightarrow \phid
p$ cross section rises strongly with $W$. This behaviour is similar to that
previously found for the $\gamma^*p \rightarrow \rho^0 p$ cross section. This
strong dependence cannot be explained by production through soft pomeron
exchange. It is, however, consistent with perturbative QCD expectations, where
it reflects the rise of the gluon momentum density in the proton at small $x$.
The ratio of $\sigma (\phi) / \sigma (\rho^0)$, which has previously been
determined by ZEUS to be 0.065 $\pm$ 0.013 (stat.) in photoproduction at a mean
$W$ of 70 GeV, is measured to be 0.18 $\pm $ 0.05 (stat.) $\pm$ 0.03 (syst.) at
a mean $Q^2$ of 12.3 GeV$^2$ and mean $W$ of $\approx$ 100 GeV and is thus
approaching at large $Q^2$ the value of 2/9 predicted from the quark charges of
the vector mesons and a flavour independent production mechanism.


title: QCD Studies at LEP I

abstract:
  The high hadronic event statistics collected at the Z energy (LEP I) allowed
a good understanding of the QCD dynamics. The coupling constant $\alpha_s$ has
been measured with several methods giving a global average $\alpha_s(M_Z) =
0.122 \pm 0.004$. The flavour independence of $\alpha_s$ has been tested
obtaining $\alpha_s^b/\alpha_s^{udsc} = 0.997 \pm 0.023$. Quark-gluon jet
differencies has been observed among which $<n>_{gluon}/<n>_{quark} = 1.234 \pm
0.027$. A big role has been plaied by the silicon vertex detectors.


title:
Measurement of $Br(H\to c\bar c,gg)/Br(H\to b\bar b)$ in $e^+e^-$
  colliders at center-of-mass energy of 300 GeV

abstract:
  Once a light Higgs boson is discovered at a future e+e- collider, the next
target at the collider will be precise measurements of the Higgs boson
properties. In this paper we report a simulation study on the measurement of
the ratio Br(H->cc,gg)/Br(H->bb) at center of mass energy of 300 GeV, and show
the possibility to constrain MSSM parameters from the measurement.


title: Factorization and Color-Suppression in Hadronic B->D^(*)npi Decays

abstract:
  The factorization hypothesis and color-suppression are investigated by
analyzing the largest, to date, sample of B mesons. In all, 20 hadronic
two-body decay modes are reconstructed using 2.04 fb^-1 of data collected with
the CLEOII detector. We measure the branching fraction of five class I and five
class III decay modes and set upper limits on branching fractions of ten class
II decays. The branching fraction measurements are used to determine the BSW
parameters a_1, and a_2/a_1. In addition, we measure the fraction of B-> D^{*+}
rho^- decays which decay longitudinally polarized. The results are found to be
consistent with factorization and color-suppression.


title:
Transversal Flow of Pions as a Consequence of Rescattering Process in
  non-central Pb+Pb 158GeV/n heavy ion collisions

abstract:
  Aim of this work was to test the idea of J.-Y.Ollitrault about the parallel
squeeze-out type of transversal flow in mid-rapidity region. For this purpose
we have performed a computer simulation of the expanding pion gas created in
non-central Pb-Pb 158GeV/n collisions. A squeeze-out type of asymmetry parallel
to impact parameter in azimuthal distribution of pions is found and studied.
The asymmetry is explained as a consequence of geometry of non-central
collisions and the rescattering process.


title: A Search for Selectrons and Squarks at HERA

abstract:
  Data from electron-proton collisions at a center-of-mass energy of 300 GeV
are used for a search for selectrons and squarks within the framework of the
minimal supersymmetric model. The decays of selectrons and squarks into the
lightest supersymmetric particle lead to final states with an electron and
hadrons accompanied by large missing energy and transverse momentum. No signal
is found and new bounds on the existence of these particles are derived. At 95%
confidence level the excluded region extends to 65 GeV for selectron and squark
masses, and to 40 GeV for the mass of the lightest supersymmetric particle.


title: Structure Function Measurements at HERA and Perturbative QCD

abstract:
  New results from the H1 and ZEUS collaborations on the measurement of
cross-sections at very high Q^2 (up to 25000 GeV^2) and on the proton structure
function F_2(x,Q^2) for momentum transfers squared Q^2 >= 1.5 GeV^2 and Bjorken
x >= 3.5 10^{-5} are reported, using data collected at HERA mainly in 1994. No
deviations from the Standard Model have been observed at high Q^2 and F_2 is
seen to increase significantly with decreasing x, even in the lowest reachable
Q^2 region. Comparisons at low Q^2 with fixed target experiments and with
models based on pomeron exchange are presented. The F_2 results are well
described by a Next to Leading Order QCD fit, and are consistent at the present
level of precision with the rise at low x within this Q^2 range generated via
the DGLAP evolution equations. The gluon density is extracted and being
observed to rise at low x.


title:
Further Properties of High-Mass Multijet Events at the Fermilab
  Proton-Antiproton Collider

abstract:
  The properties of high-mass multijet events produced at the Fermilab
proton-antiproton collider are compared with leading order QCD matrix element
predictions, QCD parton shower Monte Carlo predictions, and the predictions
from a model in which events are distributed uniformly over the available
multibody phase-space. Multijet distributions corresponding to (4N-4) variables
that span the N-body parameter space are found to be well described by the QCD
calculations for inclusive three-jet, four-jet, and five-jet events. The
agreement between data, QCD Matrix Element calculations, and QCD parton shower
Monte Carlo predictions suggests that 2 -> 2 scattering plus gluon radiation
provides a good first approximation to the full LO QCD matrix element for
events with three, four, or even five jets in the final state.


title:
A Measurement of $R ={\sigma_L}/{\sigma_T}$ in Deep Inelastic
  Neutrino-Nucleon Scattering at the Tevatron

abstract:
  Measurements of neutrino-nucleon and antineutrino-nucleon differential cross
sections using the CCFR neutrino detector at Fermilab have been used to extract
preliminary values of $R ={\sigma_L}/{\sigma_T}$ in the kinematic region
$0.01<x<0.6$, and $4<Q^2<300$ GeV$^2$. The new data provide the first
measurements of $R$ in the $x<0.1$ region. The $x$ and $Q^2$ dependence of $R$
is compared with a QCD based fit to previous data. The QCD fit, which provides
an estimate of $R$ in small $x$ region where $R$ has not been previously
measured, is in good agreement with the new CCFR data.


title: New Particle Searches at Tevatron (II)

abstract:
  Various recent results of new particle searches at the Fermilab Tevatron are
presented. No evidence is found for supersymmetric particles (chargino,
gluino), leptoquark bosons and heavy gauge bosons in p-pbar collisions at
sqrt{s} = 1.8 TeV. Excluded mass regions for each particle are determined.


title: Diffractive Deep-Inelastic Scattering

abstract:
  New results on diffractive deep-inelastic $e p$ scattering at HERA are
presented using data taken in 1994 with the H1 detector. The cross section for
diffractive deep-inelastic scattering is measured in terms of a diffractive
structure function $F_2^{D(3)}(\beta,Q^2,\xpom)$ over an extended kinematic
range. The dependence of $F_2^{D(3)}$ on $\xpom$ is found not to depend on
$Q^2$, but to depend on $\beta$. Therefore the $\xpom$ dependence no longer
factorizes. The $Q^2$ and $\beta$ dependence of $F_2^{D(3)}$ is analyzed after
an integration over the dependence on $\xpom$. For fixed $\beta$ a clear rise
with $\log Q^2$ is observed, persisting up to high values of $\beta$. In terms
of the Altarelli-Parisi (DGLAP) QCD evolution equations, these scaling
violations give clear indications for a gluon dominated process. Subsequently
an attempt is made to quantify the parton content of the diffractive exchange
using the DGLAP evolution. At the starting scale a ``leading'' gluon
distribution is found which contributes about $80 \%$ of the momentum in the
diffractive exchange. Measurements of the hadronic final state (energy flow and
production of $D^{*}$ mesons) are found to be consistent with the predictions
of a model of deep-inelastic electron pomeron scattering using the information
on the parton content obtained.


title: Dangers of Unphysical Regions

abstract:
  We discuss the appearance of negative numbers of events in radiochemical
experiments and negative squared antineutrino mass $m^2_{\bar{\nu}_e}$ in
tritium beta decay. Going beyond the standard discussion about how to extract
upper limits in those cases, we show that the problem is much more profound. We
explain the circumstances which are the likely cause of the persistently
negative values of $m^2_{\bar{\nu}_e}$ in all modern tritium beta decay
experiments.


title:
Dijet Angular Distributions in Direct and Resolved Photoproduction at
  HERA

abstract:
  Jet photoproduction, where the two highest transverse energy ($\ETJ$) jets
have $\ETJ$ above 6 GeV and a jet-jet invariant mass above 23~GeV, has been
studied with the ZEUS detector at the HERA $ep$ collider. Resolved and direct
photoproduction samples have been separated. The cross section as a function of
the angle between the jet-jet axis and the beam direction in the dijet rest
frame has been measured for the two samples. The measured angular distributions
differ markedly from each other. They agree with the predictions of QCD
calculations, where the different angular distributions reflect the different
spins of the quark and gluon exchanged in the hard subprocess.


title: Future Top Physics at the Tevatron and LHC

abstract:
  Top quarks are produced at the Tevatron proton-antiproton collider at
Fermilab and at the Large Hadron (proton-proton) Collider at CERN in two ways:
as quark-antiquark pairs, and singly. For each mode, the cross sections and
future experimental yields are presented. I then discuss some precision
measurements that can be made using the anticipated large data sets. These
measurements include the top quark mass, width and branching fractions, the
electroweak Wtb coupling, and the CKM matrix element Vtb. Detailed studies of
the top quark polarization and gluon radiation will also be possible, in
addition to sensitive searches for ttbar resonances and rare decay modes.


title:
Physics and Technology of the Next Linear Collider: A Report Submitted
  to Snowmass '96

abstract:
  We present the current expectations for the design and physics program of an
e+e- linear collider of center of mass energy 500 GeV -- 1 TeV. We review the
experiments that would be carried out at this facility and demonstrate its key
role in exploring physics beyond the Standard Model over the full range of
theoretical possibilities. We then show the feasibility of constructing this
machine, by reviewing the current status of linear collider technology and by
presenting a precis of our `zeroth-order' design.


title: Physics Prospects --Why Do We Want a Linear Collider?--

abstract:
  The need to understand physics of electroweak symmetry breaking is reviewed.
An electron positron linear collider will play crucial roles in that respect.
It is discussed how the LHC and a linear collider need each other to understand
symmetry breaking mechanism unambiguously. Two popular scenarios, supersymmetry
and technicolor-like models, are used to demonstrate this point.


title:
Neutral Current Interference in the TeV Region; the Experimental
  Sensitivity at the LHC

abstract:
  The possibilities to measure lepton forward--backward asymmetries at the LHC
in the reaction pp(qqbar) --> l+l- are studied for dilepton events with masses
above 400 GeV. It is shown that such measurements allow accurate tests of the
neutral current interference structure up to about 2 TeV center of mass
energies. The sensitivity of asymmetries at the LHC to new physics is
demonstrated within the context of quark compositeness and exotic Z' scenarios.


title: Physics Opportunities of e+e- Linear Colliders

abstract:
  We describe the anticipated experimental program of an e+e- linear collider
in the energy range 500 GeV -- 1.5 TeV. We begin with a description of current
collider designs and the expected experimental environment. We then discuss
precision studies of the W boson and top quark. Finally, we review the range of
models proposed to explain the physics of electroweak symmetry breaking and
show, for each case, the central role that the linear collider experiments will
play in elucidating this physics. (to appear in Annual Reviews of Nuclear and
Particle Science)


title:
Status of the Search for nu-mu to nu-tau Oscillations with the CHORUS
  Detector

abstract:
  The CHORUS experiment is searching for nu-mu to nu-tau oscillations using an
800 kilogram emulsion target and an electronic detector. Two of four years of
running have been completed. The experiment will probe small mixing angles for
squared neutrino mass differences greater than 10 eV^2, at least one order of
magnitude better than previous limits.


title:
Large Self-affine fractality in $\p^+$p and K$^+$p collisions at 250
  GeV/$c$

abstract:
  Taking into account the anisotropy of phase space in multiparticle
production, a self-affine analysis of factorial moments was carried out on the
NA22 data for $\p^+\Pp$ and $\PK^+\Pp$ collisions at 250 GeV/$c$. Within the
transverse plane, the Hurst exponents measuring the anisotropy are consistent
with unit value (i.e. no anisotropy). They are, however, only half that value
when the longitudinal direction is compared to the transverse ones. Fractality,
indeed, turns out to be self-affine rather than self-similar in multiparticle
production. In three-dimensional phase space, power-law scaling is observed to
be better realized in self-affine than in self-similar analysis.


title:
Observation of Events with an Energetic Forward Neutron in Deep
  Inelastic Scattering at HERA

abstract:
  In deep inelastic neutral current scattering of positrons and protons at the
center of mass energy of 300 GeV, we observe, with the ZEUS detector, events
with a high energy neutron produced at very small scattering angles with
respect to the proton direction. The events constitute a fixed fraction of the
deep inelastic, neutral current event sample independent of Bjorken $x$ and
$Q^2$ in the range $ 3 \cdot 10^{-4} < \xbj < 6\cdot 10^{-3}$ and $10 < Q^2
<100$~GeV$^2$.


title:
Tests of a High Resolution Time of Flight System Based on Long and
  Narrow Scintillator

abstract:
  We have tested a prototype time-of-flight system based on bulk scintillator
block of dimensions $2.5 \times 2.5 \times 200$ cm. Using a calibration scheme
similar to the one used in actual collider experiments, we have achieved a
resolution of 71 ps using Amperex XP2020/UR photomultipliers and 81 ps using
proximity-focusing fine-mesh photomultipliers (Hamamatsu R2021). Results are
also obtained for scintillating fiber blocks of the same dimensions. Good
internal reflectivity of the bulk scintillator block resulted in resolutions
superior to the fibre blocks. A single-photon pulsed laser system was used to
study photomultipliers and the results were used in a Monte Carlo simulation of
the system to study the critical elements that determine the resolution.


title: Measurement of Rb at SLD

abstract:
  We report a new measurement of Rb=Gamma(Z -> bb)/ Gamma(Z -> hadrons) using a
double tag technique where the b selection is based on topological
reconstruction of the mass of the B-decay vertex. The measurement was performed
using a sample of 150k hadronic Z0 events collected with the SLD at the SLAC
Linear Collider during the years 1993-1995. The method utilizes the 3-D
vertexing abilities of the SLD CCD pixel vertex detector and the small stable
SLC beams to obtain a high b tagging efficiency of 37% for a purity of 97.2%.
The high purity reduces the systematics introduced by charm contamination and
correlations with Rc. We obtain a result of
Rb=0.2176+/-0.0033(stat.)+/-0.0017(syst.)+/-0.0008(Rc).
  (Presented at the XXXIst Rencontres de Moriond Electroweak Interactions and
Unified Theories, Les Arcs, Savoie, France, March 16-23, 1996.)


title: Heavy Flavour Production at HERA

abstract:
  Recent results from the experiments ZEUS and H1 on charm production in $ep$
collisions are reviewed. The topics are elastic and inelastic $J/\psi$
photoproduction, $D^*$ photoproduction differential cross sections and a first
look at the proton structure function F_2^{c\bar{c}}.


title: Rapidity Gaps in Hard Photoproduction

abstract:
  Recent results obtained from studies of diffractive processes in hard
photoproduction performed by the ZEUS collaboration using data delivered by
HERA in 1993 and 1994 are presented. In particular, we have found that $(7 \pm
3)$\% of events with two jets at a pseudorapidity interval of 3.5 to 4 are
inconsistent with a non-diffractive production mechanism. These events may be
interpreted as arising due to the exchange of a colour singlet object of
negative squared invariant mass ($-t$) around 40~GeV$^2$. We have also probed
the structure of the exchanged colour singlet object in low--$t$ diffractive
scattering. By comparing the results from photoproduction and electroproduction
processes we find that between 30\% and 80\% of the momentum of the exchanged
colour singlet object which is carried by partons is due to hard gluons.


title:
Analysis of the Tau Polarization and its Forward-Backward Asymmetry on
  the Z0

abstract:
  This thesis describes a new a measurement of the tau lepton polarization and
its forward-backward asymmetry at the Z resonance using the OPAL detector. This
measurement is based on analyses of the tau->electron, muon and pion (Kaon)
decays from a sample of 30663 tau-pair events collected in the polar angle
range of Abs(cos(theta)) <0.68 during the 1990-1992 data taking period. Taking
then the Standard Model with the V-A structure of the tau lepton decay, we
measure the average tau polarization to be <p_tau>=(-13.5+/-2.9+/-2.2)% and the
tau polarization forward-backward asymmetry to be AFBpol=(-11.0+/-3.5+/-0.5)%
where the first error is statistical and the second systematic. Combining these
figures with the OPAL <p_tau> and AFBpol measured with the tau->rho channel we
get an average tau polarization, <p_tau>=(-14.9+/-1.9+/-1.3)% and for the
asymmetry in the polarization, AFBpol=(-8.9+/-2.2+/-0.9)% . These results are
consistent with lepton universality. Combining the two results we obtain for
the electroweak mixing angle the value sin^2(theta_W)=0.2331+/-0.0023 within
the context of the Standard Model, where the error includes both statistical
and systematic uncertainties.


title: Performance of The ATLAS_A Silcion Detector with Analogue Read Out

abstract:
  The performace of an ATLAS-A silicon micro-strip detector prototype with
FELIX 128 analogue read out chip has been studied. The noise level and the
signal to noise ratio have been measured as a funtion of both detector bias and
temperature. No evidence of micro-discharge was observed for detector bias
voltages up to 300 V.


title:
Search for Anomalous WW and WZ Production in ppbar Collisions at sqrt(s)
  = 1.8 TeV

abstract:
  We present results from a search for anomalous WW and WZ production in ppbar
collisions at sqrt(s) = 1.8 TeV. We used ppbar->evjjX events observed during
the 1992-1993 run of the Fermilab Tevatron collider, corresponding to an
integrated luminosity of 13.7 +- 0.7 pb^-1. A fit to the transverse momentum
spectrum of the W boson yields direct limits on the CP-conserving anomalous
WWgamma and WWZ coupling parameters of -0.9 < delta kappa < 1.1 (with lambda =
0) and -0.6 < lambda < 0.7 (with delta kappa = 0) at the 95% confidence level,
for a form factor scale Lambda = 1.5 TeV, assuming that the WWgamma and WWZ
coupling parameters are equal.


title:
Study of Charged-Current ep Interactions at Q2 > 200 GeV2 with the ZEUS
  Detector at HERA

abstract:
  Deep inelastic charged--current reactions have been studied in $e^+p$ and
$e^-p$ collisions at a center of mass energy of about $300\,\gev$ in the
kinematic region $Q^2\greater200\,\gev^2$ and $x\greater0.006$ using the ZEUS
detector at HERA. The integrated cross sections for $Q^2\greater200\,\gev^2$
are found to be $\sigep=30.3\,{}^{+5.5}_{\mns4.2}\,{}^{+1.6}_{\mns2.6}\,{\rm
pb}$ and $\sigem=54.7\,{}^{+15.9}_{\mns\chax 9.8}\,{}^{+2.8}_{\mns3.4}\,{\rm
pb}$. Differential cross sections have been measured as functions of the
variables $x$, $y$ and $Q^2$. From the measured differential cross sections
$d\sigma/dQ^2$, the $W$ boson mass is determined to be $M_W=79\,{}^{+8}
_{-7}{}^{+4}_{-4}\,\gev$. Measured jet rates and transverse energy profiles
agree with model predictions. A search for charged--current interactions with a
large rapidity gap yielded one candidate event, corresponding to a cross
section of $\sigep(Q^2\greater200\,\gev^2;\eta_{\rm max}<2.5)=0.8\,{}_{-0.7}^
{+1.8}\,\pm0.1\,{\rm pb}$.


title: Searches at LEP 1.5

abstract:
  The energy upgrade at LEP allows new regimes to be explored in the search for
physics beyond the Standard Model. The searches for new physics using the
ALEPH, DELPHI, L3, and OPAL data are described, and the results are presented.


title: Search for D0 - D0_bar Mixing in Semileptonic Decay Modes

abstract:
  We report the result of a search for D0 - D0_bar mixing in the data from
hadroproduction experiment E791 at Fermilab. We use the D* tag and semileptonic
decay vertices of D0 to look for wrong-sign decays with mixing time dependence.


title:
Measurement of B(D_s+ -> mu+ nu_mu)/B(D_s+ -> phi mu+ nu_mu) and
  Determination of the Decay Constant f_{D_s}

abstract:
  We have observed $23.2 \pm 6.0_{-0.9}^{+1.0}$ purely-leptonic decays of
$D_s^+ -> \mu^+ \nu_\mu$ from a sample of muonic one prong decay events
detected in the emulsion target of Fermilab experiment E653. Using the $D_s^+
-> \phi \mu^+ \nu_\mu$ yield measured previously in this experiment, we obtain
$B(D_s^+ --> \mu^+ \nu_\mu) / B(D_s^+ --> \phi \mu^+ \nu_\mu) =0.16 \pm 0.06
\pm 0.03$. In addition, we extract the decay constant $f_{D_s}=194 \pm 35 \pm
20 \pm 14 MeV$.


title: Jet Decorrelation and Jet Shapes at the Tevatron

abstract:
  We present results on measurements of jet shapes and jet azimuthal
decorrelation from $\overline{p}p$ collisions at $\sqrt{s}=1.8$ TeV using data
collected during the 1992--1993 run of the Fermilab Tevatron. Jets are seen to
narrow both with increasing $E_T$ and increasing rapidity. While HERWIG, a
parton shower Monte Carlo, predicts slightly narrower jets, it describes the
trend of the data well; NLO QCD describes qualitative features of the data but
is sensitive to both renormalization scale and jet definitions. Jet azimuthal
decorrelation has been measured out to five units of pseudorapidity. While
next--to--leading order QCD and a leading--log approximation based on BFKL
resummation fail to reproduce the effect, HERWIG describes the data well.


title:
Measurement of the F2 structure function in deep inelastic scattering
  using 1994 data from the ZEUS detector at HERA

abstract:
  We present measurements of the structure function \Ft\ in $e^+p$ scattering
at HERA in the range $3.5\;\Gevsq < \qsd < 5000\;\Gevsq$. A new reconstruction
method has allowed a significant improvement in the resolution of the kinematic
variables and an extension of the kinematic region covered by the experiment.
At $ \qsd < 35 \;\Gevsq$ the range in $x$ now spans $6.3\cdot 10^{-5} < x <
0.08$ providing overlap with measurements from fixed target experiments. At
values of $Q^2$ above 1000 GeV$^2$ the $x$ range extends to 0.5. Systematic
errors below 5\perc\ have been achieved for most of the kinematic region. The
structure function rises as \x\ decreases; the rise becomes more pronounced as
\qsd\ increases. The behaviour of the structure function data is well described
by next-to-leading order perturbative QCD as implemented in the DGLAP evolution
equations.


title:
Ratios of bottom meson branching fractions involving J/psi mesons and
  determination of b quark fragmentation fractions

abstract:
  We report a measurement of the ratios of the decay rates of the B^+, B^0 and
B^0_s mesons into exclusive final states containing a J/psi meson. The final
states were selected from 19.6 pb^{-1} of p-pbar collisions recorded by the
Collider Detector at Fermilab. These data are interpreted to determine the
bquark fragmentation fractions f_u, f_d and f_s. We also determine the
branching fractions for the decay modes B^+ --> J/psi K^+, B^+ --> J/psi
K^*(892)^+, B^0 --> J/psi K^0, B^0 --> J/psi K^*(892)^0 and B_s^0 --> J/psi
phi(1020). We discuss the implications of these measurements to B meson decay
models.


title: Strangeness in Nuclear Collisions

abstract:
  Data on the mean multiplicity of strange hadrons produced in minimum bias
proton--proton and central nucleus--nucleus collisions at momenta between 2.8
and 400 GeV/c per nucleon have been compiled. The multiplicities for
nucleon--nucleon interactions were constructed. The ratios of strange particle
multiplicity to participant nucleon as well as to pion multiplicity are larger
for central nucleus--nucleus collisions than for nucleon--nucleon interactions
at all studied energies. The data at AGS energies suggest that the latter ratio
saturates with increasing masses of the colliding nuclei. The strangeness to
pion multiplicity ratio observed in nucleon--nucleon interactions increases
with collision energy in the whole energy range studied. A qualitatively
different behaviour is observed for central nucleus--nucleus collisions: the
ratio rapidly increases when going from Dubna to AGS energies and changes
little between AGS and SPS energies. This change in the behaviour can be
related to the increase in the entropy production observed in central
nucleus-nucleus collisions at the same energy range. The results are
interpreted within a statistical approach. They are consistent with the
hypothesis that the Quark Gluon Plasma is created at SPS energies, the critical
collision energy being between AGS and SPS energies.


title: Strange and Non-Strange (Anti-)Baryon Production at 200 GeV per Nucleon

abstract:
  Rapidity distributions of net hyperons ($\Lambda - \overline{\Lambda}$) are
compared to distributions of participant protons ($p - \overline{p}$).
Strangeness production (mean multiplicities of produced $\Lambda/\Sigma^0$
hyperons and $\langle K + \overline{K} \rangle$) in central nucleus-nucleus
collisions is shown for different collision systems at different energies. An
enhanced production of $\overline{\Lambda}$ compared to $\overline{p}$ is
observed at 200 GeV per nucleon.


title: New data on OZI rule violation in bar{p}p annihilation at rest

abstract:
  The results of a measurement of the ratio R = Y(phi pi+ pi-) / Y(omega pi+
pi-) for antiproton annihilation at rest in a gaseous and in a liquid hydrogen
target are presented. It was found that the value of this ratio increases with
the decreasing of the dipion mass, which demonstrates the difference in the phi
and omega production mechanisms. An indication on the momentum transfer
dependence of the apparent OZI rule violation for phi production from the 3S1
initial state was found.


title: Local Multiplicity Fluctuations in Z decay

abstract:
  Local multiplicity fluctuations of hadrons produced in the decay of $Z^0$
were studied on the basis of L3 data. In addition to the
normalized-factorial-moment method, the fluctuations were studied for the first
time by the use of bunching parameters. A strong multifractal structure was
observed inside jets. JETSET 7.4 PS describes the fluctuations in the azimuthal
angle defined with respect to the beam axis reasonably well. For the
fluctuations in rapidity, defined with respect to the thrust axis and in the
four-momentum-difference variable, JETSET 7.4 PS overestimates the
fluctuations.


title: First Study of Rapidity Gaps in e+e- Annihilation

abstract:
  We present the first study of rapidity gaps in e+e- annihilations using Z0
decays collected by the SLD experiment at SLAC. Our measured rapidity gap
spectra fall exponentially with increasing gap size over five decades, and we
observe no anomalous class of events containing large gaps. This supports the
interpretation of the large-gap events measured in pp and ep collisions in
terms of exchange of color-singlet objects. The presence of heavy flavors or
additional jets does not affect these conclusions.


title: Mass Limit for the Lightest Neutralino

abstract:
  Indirect limits on the mass of the lightest neutralino are derived from the
results of searches for charginos, neutralinos, and sleptons performed with
data taken by the ALEPH Collaboration at centre-of-mass energies near the Z
peak and at 130 and 136 GeV. Within the context of the Minimal Supersymmetric
Standard Model and when $M_{\tilde\nu}\ge 200$ GeV/c^2, the bound $M_\chi>12.8$
GeV/c^2 at the 95\% confidence level applies for any $\tan\beta$. The impact of
lighter sneutrinos is presented in the framework of SUSY grand unified
theories; a massless neutralino is allowed only for a narrow range of
$\tan\beta$, $\mu$, and the scalar mass parameter $m_0$. Finally, by including
Higgs mass constraints and requiring that radiative electroweak symmetry
breaking occur, more stringent bounds on $M_\chi$ as a function of $\tan\beta$
are derived.


title:
Strangeness Production in Deep-Inelastic Positron-Proton Scattering at
  HERA

abstract:
  Measurements are presented of $K^0$ meson and $\Lambda$ baryon production in
deep-inelastic positron-proton scattering (DIS) in the kinematic range $10 <
Q^2 < 70 $GeV$^2$ and $10^{-4} < x < 10^{-2}$. The measurements, obtained using
the H1 detector at the HERA collider, are discussed in the light of possible
mechanisms for increased strangeness production at low Bjorken-$x$. Comparisons
of the $x_F$ spectra, where $x_F$ is the fractional longitudinal momentum in
the hadronic centre-of-mass frame, with results from electron-positron
annihilation are made. The $x_F$ spectra and the $K^0$ ``seagull'' plot are
compared with previous DIS results. The mean $K^0$ and $\Lambda$ multiplicities
are studied as a function of the centre-of-mass energy $W$ and are observed to
be consistent with a logarithmic increase with $W$ when compared with previous
measurements. A comparison of the levels of strangeness production in
diffractive and non-diffractive DIS is made. An upper limit of $0.9 $nb, at the
95% confidence level, is placed on the cross-section for QCD instanton induced
events.


title: Measurement of the $W$ Boson Mass

abstract:
  A measurement of the mass of the $W$ boson is presented based on a sample of
5982 $W \rightarrow e \nu$ decays observed in $p\overline{p}$ collisions at
$\sqrt{s}$ = 1.8~TeV with the D\O\ detector during the 1992--1993 run. From a
fit to the transverse mass spectrum, combined with measurements of the $Z$
boson mass, the $W$ boson mass is measured to be $M_W = 80.350 \pm 0.140
(stat.) \pm 0.165 (syst.) \pm 0.160 (scale) GeV/c^2$.


title:
Inclusive $D^0$ and $D^*\pm$ Production in Deep Inelastic $ep$
  Collisions at HERA

abstract:
  First results on inclusive D0 and D* production in deep inelastic $ep$
scattering are reported using data collected by the H1 experiment at HERA in
1994. Differential cross sections are presented for both channels and are found
to agree well with QCD predictions based on the boson gluon fusion process. A
charm production cross section for 10 GeV$^2\le Q^2\le100$~GeV$^2$ and $0.01\le
y\le0.7$ of $\sigma(ep\to c\barcX) = (17.4 \pm 1.6 \pm 1.7 \pm 1.4)$~nb is
derived. A first measurement of the charm contribution F2_charm(x,Q^2) to the
proton structure function for Bjorken $x$ between $8\cdot10^{-4}$ and
$8\cdot10^{-3}$ is presented. In this kinematic range a ratio F2_charm/F2=
0.237\pm0.021{+0.043\atop-0.039}$ is observed.


title: A Compact Gas Cerenkov Detector with Novel Optics

abstract:
  We discuss the design and performance of a threshold Cerenkov counter for
identification of charged hadrons. The radiator is pressurized gas, which is
contained in thin-walled cylindrical modules. A mirror system of novel design
transports Cerenkov photons to photomultiplier tubes. This system is compact,
contains relatively little material, and has a large fraction of active volume.
A prototype of a module designed for the proposed CLEO III detector has been
studied using cosmic rays. Results from these studies show good agreement with
a detailed Monte Carlo simulation of the module and indicate that it should
achieve separation of pions and kaons at the 2.5-3.0sigma level in the momentum
range 0.8-2.8 GeV/c. We predict performance for specific physics analyses using
a GEANT-based simulation package.


title: Search for CP Violation in the Decay Z -> b (b bar) g

abstract:
  About three million hadronic decays of the Z collected by ALEPH in the years
1991-1994 are used to search for anomalous CP violation beyond the Standard
Model in the decay Z -> b \bar{b} g. The study is performed by analyzing
angular correlations between the two quarks and the gluon in three-jet events
and by measuring the differential two-jet rate. No signal of CP violation is
found. For the combinations of anomalous CP violating couplings, ${\hat{h}}_b =
{\hat{h}}_{Ab}g_{Vb}-{\hat{h}}_{Vb}g_{Ab}$ and $h^{\ast}_b =
\sqrt{\hat{h}_{Vb}^{2}+\hat{h}_{Ab}^{2}}$, limits of \hat{h}_b < 0.59$ and
$h^{\ast}_{b} < 3.02$ are given at 95\% CL.


title: New Observations of Top at CDF

abstract:
  We report preliminary results from the analyses looking for top candidates in
the channel with 6 jets in the final state (all hadronic) and in the dilepton
channel with one tau lepton (tau dilepton), using a data sample of 110 pb^{-1}
collected by the CDF experiment at the Fermilab Tevatron Collider.


title: The discovery of the top quark

abstract:
  Evidence for pair production of a new particle consistent with the Standard
Model top quark has been reported recently by groups studying proton
anti-proton collisions at 1.8 TeV center of mass energy at the Fermi National
Accelerator Laboratory. In this paper we review the history of the search for
the top quark in electron positron and proton anti-proton collisions. We report
on a number of precise electro-weak measurements and the value of the top quark
mass which can be extracted from these measurements within the context of the
Standard Model. We review the theoretical predictions for top quark production
and the dominant backgrounds. We describe the collider and the detectors that
were used to measure the pair production process and follow on to describe the
data from which the existence of the top quark is evinced. Finally, we present
possible measurements that could be made in the future with more data,
measurements of quantities that would confirm the nature of this particle, the
details of its production in hadron collisions, and its decay properties.


title: Baryon production in ALEPH

abstract:
  Several recent results of the ALEPH Collaboration covering different aspects
of baryon production on the Z resonance are presented. In particular production
rates of hyperons, the full kinematical reconstruction of the Lambda_b,
observation of Xi_b in its semileptonic decay, and the measurements of the
polarization of Lambda and Lambda_b baryons are discussed.


title: Top Quark Studies at Hadron Colliders

abstract:
  The techniques used to study top quarks at hadron colliders are presented.
The analyses that discovered the top quark are described, with emphasis on the
techniques used to tag b-quark jets in candidate events. The most recent
measurements of top quark properties by the CDF and DZero collaborations are
reviewed, including the top quark cross section, mass, branching fractions and
production properties.
  Future top quark studies at hadron colliders are discussed, and predictions
for event yields and uncertainties in the measurements of top quark properties
are presented.


title:
A search for Neutral Heavy Vector Gauge Bosons in pbar-p collisions at
  sqrt{s} = 1.8 TeV

abstract:
  A search for a neutral heavy vector gauge boson, Zprime, was conducted in
pbar-p collisions using 110pb$^{-1}$ of data obtained at the Collider Detector
at Fermilab. We present preliminary 95% CL limits on the production of Zprime
in different models using its e+e- and mu+mu- decay modes.


title:
Updated Electroweak Measurements from Neutrino-Nucleon Deeply Inelastic
  Scattering at CCFR

abstract:
  We report the results of a study of electroweak parameters from observations
of neutral-current $\nu$N deeply inelastic scattering in the CCFR detector at
the FNAL Tevatron Quadrupole Triplet neutrino beam. An improved extraction of
the weak mixing angle in the on-shell renormalization scheme, incorporating
additional data and with an improved technique for constraining systematic
errors, is presented. Within the Standard Model, this result constrains the W
mass with a precision comparable to that from direct measurements. The result
is also presented in a model-independent form, as constraints on
neutral-current quark-neutrino couplings, to facilitate comparisons with
theories outside the Standard Model. Using this result, limits on new
four-fermion interactions, leptoquarks and neutrino oscillations are presented.
Prospects for a successor experiment, NuTeV (FNAL-E815), are also presented.


title:
Measurement of the Charged Multiplicities in b, c and Light Quark Events
  from Z0 Decays

abstract:
  Average charged multiplicities have been measured separately in $b$, $c$ and
light quark ($u,d,s$) events from $Z^0$ decays measured in the SLD experiment.
Impact parameters of charged tracks were used to select enriched samples of $b$
and light quark events, and reconstructed charmed mesons were used to select
$c$ quark events. We measured the charged multiplicities:
  $\bar{n}_{uds} = 20.21 \pm 0.10 (\rm{stat.})\pm 0.22(\rm{syst.})$,
  $\bar{n}_{c} = 21.28 \pm 0.46(\rm{stat.}) ^{+0.41}_{-0.36}(\rm{syst.})$
  $\bar{n}_{b} = 23.14 \pm 0.10(\rm{stat.}) ^{+0.38}_{-0.37}(\rm{syst.})$, from
which we derived the differences between the total average charged
multiplicities of $c$ or $b$ quark events and light quark events: $\Delta
\bar{n}_c = 1.07 \pm 0.47(\rm{stat.})^{+0.36}_{-0.30}(\rm{syst.})$ and $\Delta
\bar{n}_b = 2.93 \pm 0.14(\rm{stat.})^{+0.30}_{-0.29}(\rm{syst.})$. We compared
these measurements with those at lower center-of-mass energies and with
perturbative QCD predictions. These combined results are in agreement with the
QCD expectations and disfavor the hypothesis of flavor-independent
fragmentation.


title: The transition from the photoproduction to the DIS region

abstract:
  This is a review of the existing ideas in modelling the transition from the
photoproduction ($Q^2 = 0$) to the deep inelastic scattering region. The
available data of the proton structure function are analyzed from the point of
view of the total $\gamma^* p$ cross section behavior with $W$ and the results
are compared to different parameterizations. The question whether DIS processes
are hard or soft is discussed.


title: Measurement of Elastic omega Photoproduction at HERA

abstract:
  The reaction $\gamma p \rightarrow \omega p$ $(\omega \rightarrow
\pi^+\pi^-\pi^0$ and $\pi^0\rightarrow\gamma\gamma)$ has been studied in $ep$
interactions using the ZEUS detector at photon-proton centre-of-mass energies
between $70$ and $90 GeV$ and $|t| < 0.6 GeV^2$, where $t$ is the squared four
momentum transferred at the proton vertex.The elastic \ome photoproduction
cross section has been measured to be $\sigma_{\gamma p\rightarrow \omega p} =
1.21\pm 0.12\pm 0.23 \mu b$. The differential cross section $d\sigma_{\gamma
p\rightarrow \omega p} /d|t|$ has an exponential shape $e^{-b |t|}$ with a
slope $b = 10.0\pm 1.2\pm 1.3 GeV^{-2}$. The angular distributions of the decay
pions are consistent with s-channel helicity conservation. When compared to low
energy data, the features of $\omega$ photoproduction as measured at HERA
energies are in agreement with those of a soft diffractive process. Previous
measurements of the $\rho^0$ and $\phi$ photoproduction cross sections at HERA
show a similar behaviour.


title: Charged Particle Multiplicities in Deep Inelastic Scattering at HERA

abstract:
  Using the H1 detector at HERA, charged particle multiplicity distributions in
deep inelastic ep scattering have been measured over a large kinematical
region. The evolution with $W$ and $Q^2$ of the multiplicity distribution and
of the multiplicity moments in pseudorapidity domains of varying size is
studied in the current fragmentation region of the hadronic centre-of-mass
frame. The results are compared with data from fixed target lepton-nucleon
interactions, $e^+e^-$ annihilations and hadron-hadron collisions as well as
with expectations from QCD based parton models. Fits to the Negative Binomial
and Lognormal distributions are presented.


title:
Preliminary Results from a Search for Disoriented Chiral Condensates at
  MiniMax

abstract:
  We report on the progress of a search for disoriented chiral condensates
(DCCs) in the far forward region at sqrt(s)=1.8 TeV. MiniMax is a small
collider experiment situated at the C0 interaction region of the Tevatron and
has been designed to measure the ratio of charged to neutral pions produced at
eta near 4.1. The distribution of this ratio is expected to be very different
for the generic binomial and DCC particle production models. We present a
method used for the search using the factorial moments of particle generating
functions, which can be extracted directly from the data. A preliminary
comparison of robust ratios of measured values and those expected from the
different models is also presented.


title: Limits on $\zp$ production at the Tevatron using CDF and D0 data

abstract:
  The contents of this document have been withdrawn pending its mailing at a
future date.


title: Charmonium and Bottomonium Production in p-pbar Collisions at CDF

abstract:
  We present measurements of charmonium and bottomonium production using a data
sample collected by CDF during the 1992-93 p-pbar collider run at the Fermilab
Tevatron.


title: Muon Polarization Working Group Report

abstract:
  We have examined the physics and the experimental feasibility at the AGS of
various kaon decay processes in which the polarization of a muon in the final
state is measured. Valuable information on CP violation, the CKM matrix or new
physics can be obtained with these measurements and therefore they are well
motivated. In particular, models of non-standard CP violation that produce the
baryon asymmetry of the universe could also produce effects observable in these
measurements. Limits from measurements such as the neutron and electron
electric dipole moment, and epsilon-prime over epsilon in neutral kaon decays
do not eliminate all of these models. We have made a more detailed examination
of the measurement of the out of the plane muon polarization in Kmu3 decays.
With our current knowledge of the AGS kaon beams and detector techniques it is
possible to measure this polarization with an error approaching 10**-4. Such an
experiment would be well justified since the sensitivity is well beyond the
current direct experimental limit (5.3 times 10**-3) and the projected
sensitivity (10**-3) of the currently running experiment at KEK in Japan.


title:
A study of the orientation and energy partition of three-jet events in
  hadronic Z0 decays

abstract:
  We have measured the distributions of the jet energies in e+e- --> qq^bar g
events, and of the three orientation angles of the event plane, using hadronic
$Z^0$ decays collected in the SLD experiment at SLAC. We find that the data are
well described by perturbative QCD incorporating vector gluons. We have also
compared our data with models of scalar and tensor gluon production, and
discuss limits on the relative contributions of these particles to three-jet
production in e+e- annihilation.


title: Properties of the a0(980) meson

abstract:
  The mass and width of the a0(980) have been independently determined from a
nearly background free data sample and the coupling constants to the eta-pi and
K-K-bar modes have been determined


title:
A search for D0-D0bar mixing and doubly-Cabibbo-suppressed decays of the
  D0 in hadronic final states

abstract:
  We present results of a search for D0-D0bar mixing and
doubly-Cabibbo-suppressed decays of the D0 in Fermilab experiment E791, a
fixed-target charm hadroproduction experiment. We look for evidence of mixing
in the decay chain D* -> pi D0 -> (K pi or K pi pi pi). If the charge of the
pion from the D* decay is the same as the charge of the kaon from the D decay
(a ``wrong-sign'' event), mixing may have occurred. Mixing can be distinguished
from other sources of wrong-sign events (such as doubly-Cabibbo-suppressed
decays) by analyzing the distribution of decay times. We see no evidence of
mixing. Allowing for possible CP violation, our results for r_{mix}, the ratio
of mixed to unmixed decays, are r_{mix}(D0bar -> D0)=(0.18_{-0.39}^{+0.43} +-
0.17)% and r_{mix}(D0 -> D0bar)=(0.70_{-0.53}^{+0.58} +- 0.18)%. The
sensitivity of these results is comparable to that of previous measurements,
but the assumptions made in fitting the data are notably more general. We
present results from many fits to our data under various assumptions. If we
assume r_{mix} = 0, we find that the ratios of doubly Cabibbo-suppressed decays
to Cabibbo-favored decays are r_{dcs}(K pi) =(0.68_{-0.33}^{+0.34} +- 0.07)%
and r_{dcs}(K pi pi pi)=(0.25_{-0.34}^{+0.36} +- 0.03)%.


title: Azimuthally Sensitive HBT Analysis

abstract:
  In the paper we investigate a possibility to perform shape-sensitive HBT
analysis in transversal plane. We study presently used Side-Out decomposition
of the correlation function and we do not find it to be very sensitive for the
detection of a shape of source distribution in transversal plane. Therefore we
suggest to use X-Y decomposition of the correlation function for the HBT
analysis. We test the method suggested on artificial and non-central Pb-Pb
158GeV/n events produced by CASCUS generator. Further possible enhancement of
the method is sketched.


title: Search for T Violation in KMU3 Decay

abstract:
  We propose a new experiment at the AGS to search for the T-violating
polarization of the muon normal to the decay plane of the K+ to mu+ pi0 nu
decay. Motivated by the need for a stronger CP violation source to account for
the baryon asymmetry of the Universe, the experiment aims to search for
T-violation beyond the Standard Model. The experiment will be performed with
in-flight decays from an intense 2 GeV/c separated K+ beam at the AGS. We
expect to analyze 10**9 events to obtain the sensitivity of delta Pt = +-
0.00013 at 1 sigma, corresponding to the sensitivity of +-0.0007 to Im(xi), an
improvement by 40 over the present limit.


title:
Study of Elastic rho0 photoproduction at HERA using the ZEUS Leading
  Proton Spectrometer

abstract:
  The differential cross section $d\sigma/dt$ for elastic $\rho^0$
photoproduction, $\gamma p \rightarrow \rho^0 p (\rho^0 \rightarrow \pi^+
\pi^-)$, has been measured in $ep$ interactions at HERA. The squared
four-momentum exchanged at the proton vertex, $t$, has been determined directly
by measuring the momentum of the scattered proton using the ZEUS Leading Proton
Spectrometer (LPS), a large scale system of silicon micro-strip detectors
operating close to the HERA proton beam. The LPS allows the measurement of the
momentum of high energy protons scattered at small angles with accuracies of
0.4% for the longitudinal momentum and 5 MeV for the transverse momentum.
Photoproduction of $\rho^0$ mesons has been investigated in the interval
$0.073< |t| <0.40 GeV^2$, for photon virtualities $Q^2<1 GeV^2$ and
photon-proton centre-of-mass energies $W$ between 50 and 100 GeV. In the
measured range, the $t$ distribution exhibits an exponential shape with a slope
parameter $b = 9.8 \pm 0.8 (stat.) \pm 1.1 (syst.) GeV^{-2}$. The use of the
LPS eliminates the contamination from events with diffractive dissociation of
the proton into low mass states.


title: Experimental studies of QCD using flavour tagged jets with DELPHI

abstract:
  Identified $b\overline{b}g$ and $q\overline{q}\gamma$ events from DELPHI are
used to measure the ratio of the mean charged particle multiplicity
distribution between gluon and quark jets. The dependence of this ratio with
the jet energy is established using about three million Z$^0$ decays. Results
from all other detectors are discussed and compared. A nice agreement is found
among all them. The ratio between the normalized total three-jet cross sections
of $b\overline{b}g$ and $q\overline{q}g, q \equiv u,d,s$ events is also
determined. The preliminary value obtained indicates that $b$ quarks are
experimentaly seen to radiate less than light quarks due to their higher mass.
The suggested experimental error is $\sim$300 MeV for the $b$ mass
determination at the M$_Z$ scale.


title: A Measurement of $R_b$ Using Multiple Tags

abstract:
  A new measurement of $R_b$ with the ALEPH detector at LEP using five mutually
exclusive hemisphere tags is presented. The preliminary result is $R_b = 0.2158
\pm 0.0009 (stat.) \pm 0.0011 (syst.)$.


title: The Presampler for the Forward and Rear Calorimeter in the ZEUS Detector

abstract:
  The ZEUS detector at HERA has been supplemented with a presampler detector in
front of the forward and rear calorimeters. It consists of a segmented
scintillator array read out with wavelength-shifting fibers. We discuss its
desi gn, construction and performance. Test beam data obtained with a prototype
presampler and the ZEUS prototype calorimeter demonstrate the main function of
this detector, i.e. the correction for the energy lost by an electron
interacting in inactive material in front of the calorimeter.


title: Rare D Meson Decays at HERA

abstract:
  A status report on the prospects of measuring rare decays of charmed mesons
at HERA is given. Based on actual experience with measuring charm at HERA, the
sensitivity on limits of rare decays is estimated.


title: Search for Excited Fermions with the H1 Detector

abstract:
  We present a search for excited electrons, neutrinos and quarks using the H1
detector at the $ep$ collider HERA, based on data taken in 1994 with an
integrated luminosity of 2.75 pb$^{-1}$. Radiative decays of excited quarks and
neutrinos have been investigated as well as decays of excited electrons into
all possible electroweak gauge bosons. No evidence for new particle production
is found and exclusion limits are derived.


title: Diffractive Interactions

abstract:
  The general framework of diffractive deep inelastic scattering is introduced
and reports given in the session on diffractive interactions at the
International Workshop on Deep-Inelastic Scattering and Related Phenomena,
Rome, April 1996, are presented.


title: Analysis of the pi0pi0 Final State in the pi- p reactions at 18.3 GeV/c

abstract:
  The reaction pi- p -> pi0 pi0 n may be used to examine both scalar and tensor
mesons. The f0(980) signature changes from destructive interference at small
momentum transfer to an enhancement at large momentum transfer. The f2(1270)
production mechanism also changes as a function of momentum transfer. Unnatural
parity exchange dominates at small |t|, natural parity exchange becomes the
leading production mechanism at larger momentum transfer. These results are
based on 188,000 pi- p -> pi0 pi0 n events collected by the E852 collaboration
at Brookhaven National Laboratory in 1994.


title: Measurement of Dijet Angular Distributions at CDF

abstract:
  We have used 106 pb^-1 of data collected in proton-antiproton collisions at
sqrt(s)=1.8 TeV by the Collider Detector at Fermilab to measure jet angular
distributions in events with two jets in the final state. The angular
distributions agree with next to leading order (NLO) predictions of Quantum
Chromodynamics (QCD) in all dijet invariant mass regions. The data exclude at
95% confidence level (CL) a model of quark substructure in which only up and
down quarks are composite and the contact interaction scale is Lambda_ud(+) <
1.6 TeV or Lambda_ud(-) < 1.4 TeV. For a model in which all quarks are
composite the excluded regions are Lambda(+) < 1.8 TeV and Lambda(-) < 1. 6
TeV.


title: On the Study of BBbar Correlations at HERA-B

abstract:
  We analyze the possibility of studying the heavy flavour hadroproduction
properties at the HERA-B experiment. In addition to the high statistics single
inclusive B spectra measurements, the measurement of the BBbar meson
correlations is considered. The techniques of momentum estimators, widely used
in the charm sector, are demonstrated to be useful for the BBbar correlation
studies at HERA-B. The kinematic limits for the precision of the momentum
estimator within which the pair spectra can be measured are determined. The
errors are weakly dependent on the topology of the multibody B meson decay.


title: Top Quark Physics Results from CDF and D0

abstract:
  I summarize recent top quark physics results from the Fermilab Tevatron
experiments. Since the observation of the top quark by CDF and D0 in 1995, the
experimental focus has shifted to a detailed study of the top quark's
properties. This article describes recent measurements of the top quark
production cross section, mass, kinematic properties, branching ratios,
$V_{tb}$, and the W polarization in top decays.


title: Experimental Tests of Asymptotic Freedom

abstract:
  Measurements which probe the energy dependence of $\alpha_s$, the coupling
strength of the strong interaction, are reviewed. Jet counting in $e^+ e^-$
annihilation, combining results obtained in the centre of mass energy range
from 22 to 133 GeV, provides direct evidence for an asymptotically free
coupling, without the need to determine explicit values of $\alpha_s$. Recent
results from jet production in $e p$ and in $p \overline{p}$ collisions,
obtained in single experiments spanning large ranges of momentum transfer,
$Q^2$, are in good agreement with the running of $\alpha_s$ as predicted by
QCD. Mass spectra of hadronic decays of $\tau$-leptons are analysed to probe
the running $\alpha_s$ in the very low energy domain, $0.7 GeV^2 < Q^2 <
M_\tau^2$. An update of the world summary of measurements of $\alpha_s(Q^2)$
consistently proves the energy dependence of $\alpha_s$ and results in a
combined average of $\alpha_s(M_Z) = 0.118 \pm 0.006$.


title: Future Prospects for Studying CP Violation in B-Meson Decays

abstract:
  Experimental prospects for observing CP violation in B-meson decays are
reviewed. Comparisons are made for various options: experiments at $e^+ e^-$
B-Meson Factories, HERA and the TEVATRON will produce results in near future.
They will have a good chance to discover CP violation in B-meson decays. On a
longer time scale, experiments at the LHC will aim at accurate measurements to
make a precision test of the standard model in CP violation.


title: On Measuring the top quark mass using the dilepton decay modes

abstract:
  We demonstrate a new likelihood method for extracting the top quark mass from
events of the type ttbar-->bW(l+nu)bW(l+nu) This method estimates the top quark
mass correctly from an ensemble of dilepton events. The method proposed by
Dalitz and Goldstein [1] is shown to result in a systematic underestimation of
the top quark mass. Effects due to the spin correlations between the top and
anti-top quarks are shown to be unimportant in estimating the mass of the top
quark.


title: Future Measurement of the Longitudinal Proton Structure Function at HERA

abstract:
  A study is presented of a possible future measurement of the longitudinal
structure function $F_{L}(x,Q^{2})$ with different proton beam energies at
HERA.


title: Jet Production in Photon-Photon Interactions

abstract:
  The inclusive one- and two-jet cross-sections are measured in collisions of
quasi-real photons at e+e- centre-of-mass energies of 130 and 136 GeV using the
OPAL detector at LEP. Jets are reconstructed with a cone jet finding algorithm.
The jet cross-sections are compared to next-to-leading order (NLO) perturbative
QCD calculations. Transverse energy flows in jets are studied separately for
direct and resolved two-photon events.


title:
First Measurement of the Left-Right Charge Asymmetry in Hadronic Z Boson
  Decays and a New Determination of sin^2(theta_eff)

abstract:
  We present the first measurement of the left-right charge asymmetry A_Q^{obs}
in hadronic Z boson decays. This was performed at E_cm = 91.27 GeV with the SLD
at the SLAC Linear Collider with a polarized electron beam. Using 89838 events,
we obtain A_Q^{obs}=0.225+-0.056+-0.019 which leads to a measurement of the
electron left-right asymmetry parameter, A_e=0.162+-0.041+-0.014, and
sin^2(theta_eff)=0.2297+-0.0052 +-0.0018. Also, the A_Q^{obs} measurement
combined with the left-right cross section asymmetry determines A_e
independently of the value of the electron-beam polarization.


title: Determination of Electroweak Parameters at the SLC

abstract:
  We present an improved measurement of the left-right cross section asymmetry
Alr for Z boson production by e+e- collisions. The measurement was performed at
a center-of-mass energy of 91.28 GeV with the SLD detector at the SLAC Linear
Collider (SLC) during the 1994-95 running period. The luminosity-weighted
average polarization of the SLC electron beam during this run was measured to
be (77.23 +/- 0.52)%. Using a sample of 93,644 hadronic Z decays, we measure
the pole asymmetry Alr0 to be 0.1512 +/- 0.0042(stat.) +/- 0.0011(syst.) which
is equivalent to an effective weak mixing angle of 0.23100 +/- 0.00054(stat.)
+/- 0.00014(syst.). We also present a preliminary direct measurement of the
Z-lepton coupling asymmetries A_e,A_mu, and A_tau extracted from the
differential cross section observed in leptonic Z decays. We combine these
results with our previous Alr measurement to obtain a combined determination of
the weak mixing angle of 0.23061 +/- 0.00047.


title: B-physics potential of ATLAS: an update

abstract:
  The B-physics potential of the ATLAS experiment at LHC is described.
Simulation results are shown for the measurement of sin(2beta), with an
emphasis on new tagging techniques. Other CP-violation measurements are
described briefly. New limits are shown for the reach of the x_s-measurement,
resulting from increased statistics and improved fitting methods. Some rare
decay modes of B-mesons can be easily seen in ATLAS. Analyses of channels B->
mu+mu-(X) are presented here.


title: Charmonium Production in Fermilab E789

abstract:
  Using a sample of >10^5 J/psi to mu+mu- decays, Fermilab experiment 789 has
studied production of J/psi and psi-prime in 800-GeV proton-nucleon collisions.
Differential cross sections and nuclear dependences have been measured for
charmonium as well as for charm and beauty production. While charm and beauty
production are consistent with perturbative QCD calculations, charmonium cross
sections exceed the predictions of the color-singlet model by large factors,
suggesting that additional mechanisms (such as color-octet production) may play
important roles. Nuclear dependences of production cross sections may offer a
new tool for the detailed understanding of charmonium production.


title: High-p_T Particles in the Forward Region at HERA

abstract:
  In order to probe the dynamics of parton evolution in deep inelastic
scattering at small x, high-p_T particles produced centrally in pseudorapidity
are studied. In the BFKL mechanism gluon radiation is expected to be more
abundant than for DGLAP evolution with strong ordering of the gluon transverse
momenta, leading to harder p_T spectra. The proposed measurements require
charged particle tracking capability as much forward as possible in the HERA
laboratory frame, for example with a Very Forward Silicon Tracker, and high
luminosity for detailed studies.


title: Separation of \gamma/\pi^0 showers at high energies

abstract:
  We have designed and carried out simulation studies of a two layer Shower
Maximum Detector diagonally off-set (SMD-dos) optimized for the separation of
\pi^0 showers from \gamma showers in the 30 to 150 GeV energy range. For 90%
\gamma acceptance the SMD-dos yields \pi^0 rejection efficiency of 92+-4%,
87+-4% and 32+-2%, respectively, for 30, 50 and 150 GeV incident energies. We
find that the SMD-dos is superior to a conventional geometry single-layer or
mutiple-layer shower maximum detector (SMD), of equal granularity, by an
average factor of ~1.5 over the 50 to 150 GeV energy range. We also find that
the SMD-dos gives better \pi^0 rejection, for the same number of channels, than
a SMD. At hadron - hadron colliders the signature of choice for the detection
of the Higgs particle, in the mass range of 120 to 160 GeV, is via the decay
H-->\gamma\gamma. The addition of a SMD-dos to the planned detectors at the LHC
would significantly reduce the background to the \gamma-signal coming from
prolific \pi^0 production.


title:
Measurement of Charged Particle Transverse Momentum Spectra in Deep
  Inelastic Scattering

abstract:
  Transverse momentum spectra of charged particles produced in deep inelastic
scattering are measured as a function of the kinematic variables x_B and Q2
using the H1 detector at the ep collider HERA. The data are compared to
different parton emission models, either with or without ordering of the
emissions in transverse momentum. The data provide evidence for a relatively
large amount of parton radiation between the current and the remnant systems.


title:
Deep Inelastic Scattering of Polarized Electrons by Polarized $^3$He and
  the Study of the Neutron Spin Structure

abstract:
  The neutron longitudinal and transverse asymmetries $A^n_1$ and $A^n_2$ have
been extracted from deep inelastic scattering of polarized electrons by a
polarized $^3$He target at incident energies of 19.42, 22.66 and 25.51 GeV. The
measurement allows for the determination of the neutron spin structure
functions $g^n_1 (x,Q^2)$ and $g^n_2(x,Q^2)$ over the range $0.03 < x < 0.6$ at
an average $Q^2$ of 2 (GeV$/c)^2$. The data are used for the evaluation of the
Ellis-Jaffe and Bjorken sum rules. The neutron spin structure function $g^n_1
(x,Q^2)$ is small and negative within the range of our measurement, yielding an
integral ${\int_{0.03}^{0.6} g_1^n(x) dx}= -0.028 \pm 0.006 (stat) \pm 0.006
(syst) $. Assuming Regge behavior at low $x$, we extract $\Gamma_1^n=\int^1_0
g^n_1(x)dx = -0.031 \pm 0.006 (stat)\pm 0.009 (syst) $. Combined with previous
proton integral results from SLAC experiment E143, we find $\Gamma_1^p -
\Gamma_1^n = 0.160 \pm 0.015$ in agreement with the Bjorken sum rule prediction
$\Gamma^p_1 - \Gamma ^n_1 = 0.176 \pm 0.008$ at a $Q^2$ value of 3 (GeV$/c)^2$
evaluated using $\alpha_s = 0.32\pm 0.05$.


title: Laser cooling of electron beams for linear colliders

abstract:
  A novel method of electron beam cooling is considered which can be used for
linear colliders. The electron beam is cooled during collision with focused
powerful laser pulse. With reasonable laser parameters (laser flash energy
about 10 J) one can decrease transverse beam emittances by a factor about 10
per one stage. The ultimate transverse emittances are much below those
achievable by other methods. Beam depolarization during cooling is about 5--15
% for one stage. This method is especially useful for photon colliders and
opens new possibilities for e+e- colliders.


title: B Decay Studies at Cleo

abstract:
  Weak decays of heavy flavored hadrons are sensitive probes of several facets
of the Standard Model. In particular the experimental study of B meson
semileptonic decaysis starting to pin down the quark mixing parameters in the
Cabibbo Kobayashi Maskawa matrix. In addition, some features of the
non--perturbative regime of the strong interaction are probed by these decays.
New results from the CLEO experiment at the CESR electron-positron collider,
based on a data sample of up to 3.5 inverse femtobarn, provide crucial
information on both of these aspects of heavy flavor phenomenology.


abstract:
  Previous results for the prospects of B_s mixing measurement in the ATLAS
experiment at LHC are updated. The improved analysis method of the studied
decay channels B_s -> D_s pi and B_s -> D_s a_1, combined with most recent
values for the branching ratios and the B_s lifetime, leads to the new ATLAS
sensitivity range for the x_s measurement: x_s^{max} = 42. An extensive study
is done in order to estimate how x_s^{max} is influenced by the B-decay
proper-time resolution of the vertex detector, as well as by the number of
events and by the signal-to-background ratio.


title:
Measurement of the Branching Ratio B(D+ --> rho^0 l nu)/B(D+ --> K*0 l
  nu)

abstract:
  We report a measurement of the branching ratio B(D+-->rho^0 l nu)/ B(D+-->K*0
l nu) from the Fermilab charm hadroproduction experiment E791. Based on signals
of 49+-17 events in the D+--> rho^0 e nu mode and 54+-18 events in the D+-->
rho^0 mu nu mode, we measure B(D+-->rho^0 e nu)/B(D+-->K*0 e nu) =
0.045+-0.014+-0.009, and B(D+-->rho^0 mu nu)/B(D+-->K*0 mu nu) =
0.051+-0.015+-0.009. Combining the results from both the electronic and muonic
modes, we obtain B(D+-->rho^0 l nu)/B(D+-->K*0 l nu) = 0.047+-0.013. This
result is compared to theoretical predictions.


title:
Photoproduction evidence for and against hidden-strangeness states near
  2 GeV

abstract:
  Experimental evidence from coherent diffractive proton scattering has been
reported for two narrow baryonic resonances which decay predominantly to
strange particles. These states, with masses close to 2.0 GeV would, if
confirmed, be candidates for hidden strangeness states with unusual internal
structure. In this paper we examine the literature on strangeness
photoproduction, to seek additional evidence for or against these states. We
find that one state is not confirmed, while for the other state there is some
mild supporting evidence favoring its existence. New experiments are called
for, and the expected photoproduction lineshapes are calculated.


title: Scale Influence on the Energy Dependence of Photon-Proton Cross Sections

abstract:
  The scale dependence of the evolution of photoproduction cross sections with
the photon-proton centre of mass energy W is studied using low Q^2 < 0.01 GeV^2
e^+p interactions collected by the H1 experiment at HERA. The value of the
largest transverse momentum of a charged particle in the photon fragmentation
region is used to define the hard scale. The slope of the $W$ dependence of the
cross section is observed to increase steeply with increasing transverse
momentum. The result is compared to measurements of the Q^2 evolution of the W
dependence of the virtual photon-proton cross section. Interpretations in terms
of QCD and in terms of Regge phenomenology are discussed.


title: The scanning Compton polarimeter for the SLD experiment

abstract:
  For the 1994/95 run of the SLD experiment at SLAC, a Compton polarimeter
measured the luminosity-weighted electron beam polarization to be (77.2 +-
0.5)%. This excellent accuracy is achieved by measuring the rate asymmetry of
Compton-scattered electrons near the kinematic endpoint. The polarimeter takes
data continuously while the electron and positron beams are in collision and
achieves a statistical precision of better than 1% in a three minute run. To
calibrate the polarimeter and demonstrate its accuracy, many scans are
frequently done. These include scans of the laser polarization, the detector
position with respect to the kinematic edge, and the laser power. Presented at
the Workshop on High Energy Polarimeters at NIKHEF, Amsterdam, The Netherlands
on September 9, 1996.


title: The polarized electron beam for the SLAC Linear Collider

abstract:
  The SLAC Linear Collider has been colliding a polarized electron beam with an
unpolarized positron beam at the Z^0 resonance for the SLD experiment since
1992. An electron beam polarization of close to 80% has been achieved for the
experiment at luminosities up to 8x10^29 cm^-2 s^-1. This is the world's first
and only linear collider, and is a successful prototype for the next generation
of high energy electron linear colliders. This paper discusses polarized beam
operation for the SLC, and includes aspects of the polarized source, spin
transport and polarimetry. Presented at the 12th International Symposium on
High Energy Spin Physics held at Amsterdam, The Netherlands September 10-14,
1996.


title: Measurement of the atmospheric neutrino flavour composition in Soudan 2

abstract:
  The atmospheric neutrino flavour ratio measured using a 1.52 kton-year
exposure of Soudan 2 is found to be 0.72 +- 0.19 +0.05 -0.07 relative to the
expected value from a Monte Carlo calculation. The possible background of
interactions of neutrons and photons produced in muon interactions in the rock
surrounding the detector has been investigated and is shown not to produce low
values of the ratio.


title: QCD and the structure of the proton

abstract:
  Measurements of structure functions and of the hadronic final state in deep
inelastic scattering at HERA are presented. The results comprise the extraction
of parton densities, measurements of the strong coupling, and the search for
novel QCD effects in the new kinematic regime at HERA.


title: Quarkonium Production in p-pbar Collisions at the Tevatron

abstract:
  Charmonium and bottomonium production is studied using $\mu^+\mu^-$ data
samples collected by the CDF and D0 experiments during the 1992-96 p-pbar
collider run at the Fermilab Tevatron. The inclusive cross sections as a
function of the transverse momentum of reconstructed quarkonium states are
measured. The results are compared with theoretical predictions, which take
into account different quarkonium production mechanisms.


title:
Semi-inclusive spin asymmetries in polarised deep inelastic electron
  scattering

abstract:
  In 1995, the HERMES experiment at DESY (Hamburg, Germany) has taken its first
data, using the 27.5 GeV polarised HERA positron beam impinging on a
longitudinally polarised internal $^3$He target. Preliminary results from the
semi-inclusive physics program are presented.


title: An Improved Measurement of the Left-Right Z0 Cross Section Asymmetry

abstract:
  We present a new measurement of the left-right cross section asymmetry (ALR)
for Z boson production by e+e- collisions. The measurement was performed at a
center-of-mass energy of 91.28 GeV with the SLD detector at the SLAC Linear
Collider (SLC). The luminosity-weighted average polarization of the SLC
electron beam was (77.23+-0.52)%. Using a sample of 93,644 Z decays, we measure
the pole-value of the asymmetry, ALR0, to be
0.1512+-0.0042(stat.)+-0.0011(syst.) which is equivalent to an effective weak
mixing angle of sin**2(theta_eff)=0.23100+-0.00054(stat.)+-0.00014(syst.).


title:
Measurement of $xF_3$, $F_2$ Structure Functions and Gross--Llewellyn
  Smith Sum Rule with IHEP--JINR Neutrino Detector

abstract:
  The isoscalar structure functions xF_3 and F_2 are measured as functions of x
averaged over all Q^2 permissible for the range 6 to 28 GeV of incident
(anti)neutrino energy. With the measured values of xF_3, the value of the
Gross-Llewellyn Smith sum rule is found to be $\int_{0}^{1}{F_3 dx} =
2.13\pm0.38 (stat)\pm 0.26 (syst)$. The QCD analysis of xF_3 provides
$\Lambda_{\overline{MS}} =358 \pm 59 MeV$ . The obtained value of the strong
interaction constant $\alpha_S (M_Z)=0.120^{+3}_{-4}$ is larger than most of
the deep inelastic scattering results.


title:
A High Statistics Search for muon-neutrino(anti-muon-neutrino) --->
  electron-neutrino(anti-electron-neutrino) Oscillations in the Small Mixing
  Angle Regime

abstract:
  Limits on $\nu_\mu (\overline{\nu}_\mu) \to \nu_e (\overline{\nu}_e)$
oscillations based on a statistical separation of $\nu_e N$ charged current
interactions in the CCFR detector at Fermilab are presented. $\nu_e$
interactions are identified by the difference in the longitudinal shower energy
deposition pattern of $\nu_e N \rightarrow eX$ versus $\nu_\mu N \to \nu_\mu X$
interactions. Neutrino energies range from 30 to 600 GeV with a mean of 140
GeV, and $\nu_\mu$ flight lengths vary from 0.9 km to 1.4 km. The lowest 90%
confidence upper limit in $sin^2 2\alpha$ of $1.1 \times 10^{-3}$ is obtained
at $\Delta m^2 \sim 300 eV^2$. For $sin^2 2\alpha = 1$, $\Delta m^2 > 1.6 eV^2$
is excluded, and for $\Delta m^2 \gg 1000 eV^2$, $sin^2 2\alpha > 1.8 \times
10^{-3}$ is excluded. This result is the most stringent limit to date for
$\Delta m^2 > 25 eV^2$ and it excludes the high $\Delta m^2$ oscillation region
favoured by the LSND experiment. The $\nu_\mu$-to-$\nu_e$ cross-section ratio
was measured as a test of $\nu_\mu (\bar\nu_\mu) \leftrightarrow \nu_e
(\bar\nu_e)$ universality to be $1.026 \pm 0.055$.


title: Status of the AMANDA South Pole Neutrino Detector

abstract:
  Initial deployment of optical modules near 1 and 2 kilometer depth indicate
that deep polar ice is the most transparent known natural solid. Experience
with early data has revealed that a detector, conceived to measure muons
tracks, can also measure energy of high energy neutrinos as well as bursts of
MeV neutrinos, e.g. produced by supernovae and gamma ray bursts. We plan to
complete AMANDA this austral summer to form a detector of 11 deep strings
instrumented over 400 meters height with 300 optical modules. We will argue
that ice is the ideal medium to deploy a future kilometer-scale detector and
discuss the first deployment of 10 strings of kilometer length.


title:
Measurements of Four-Fermion Production via Neutral Elektroweak Currents
  at LEP

abstract:
  Four-fermion production via electroweak neutral currents has been measured by
all four LEP collaborations at center-of-mass energies near the Z resonance and
for the first time also at energies well above the Z peak. Essentially all
possible final states have been covered in four different topologies.


title: Spin Physics with COMPASS

abstract:
  The recently proposed COMPASS experiment at CERN attempts a measurement of
the gluon polarisation with a precision of delta(Delta g/g) = 0.1. The
experiment uses open charm muoproduction to tag the photon-gluon fusion
process.


title:
Determination of the Longitudinal Proton Structure Function F_L(x,Q^2)
  at Low x

abstract:
  A measurement of the inclusive cross section for the deep-inelastic
scattering of positrons off protons at HERA is presented at momentum transfers
$8.5 \leq Q^2 \leq 35 GeV^2$ and large inelasticity $y = 0.7$, i.e. for the
Bjorken-x range $0.00013 \leq x \leq 0.00055$. Using a next-to-leading order
QCD fit to the structure function F_2 at lower y values, the contribution of
F_2 to the measured cross section at high y is calculated and, by subtraction,
the longitudinal structure function F_{L} is determined for the first time with
an average value of $F_L=0.52 \pm 0.03 (stat)$^ {+0.25}_{-0.22}$ (syst) at
$Q^2=15.4 GeV^2$ and $x=0.000243$.


title: Electroweak Measurements from the Tevatron

abstract:
  An overview of recent electroweak physics results from the Tevatron is given.
Properties of the W and Z gauge bosons using final states containing electrons
and muons based on large integrated luminosities are presented. In particular,
measurements of the W and Z production cross sections, the W-charge asymmetry
and the measurement of the W-mass are summarized. Gauge boson self interactions
are measured by studying gauge boson pair production and limits on anomalous
gauge boson couplings are discussed.


title: Precision Electroweak Measurements

abstract:
  Recent electroweak precision measurements from e+e- and pbarp colliders are
presented. Some emphasis is placed on the recent developments in the heavy
flavor sector. The measurements are compared to predictions from the Standard
Model of electroweak interactions. All results are found to be consistent with
the Standard Model. The indirect constraint on the top quark mass from all
measurements is in excellent agreement with the direct Mt measurements. Using
the world's electroweak data in conjunction with the current measurement of the
top quark mass, the constraints on the Higgs mass are discussed.


title: Measurement of the Direct Photon Spectrum in $\Upsilon(1S)$ Decays

abstract:
  Using data taken with the CLEO II detector at the Cornell Electron Storage
Ring, we have determined the ratio of branching fractions: $R_{\gamma} \equiv
\Gamma(\Upsilon(1S) \rightarrow \gamma gg)/\Gamma(\Upsilon(1S) \rightarrow ggg)
= (2.75 \pm 0.04(stat.) \pm 0.15(syst.))%$. From this ratio, we have determined
the QCD scale parameter $\Lambda_{\overline{MS}}$ (defined in the modified
minimal subtraction scheme) to be $\Lambda_{\overline{MS}}= 233 \pm 11 \pm 59$
MeV, from which we determine a value for the strong coupling constant
$\alpha_{s}(M_{\Upsilon(1S)}) = 0.163 \pm 0.002 \pm 0.014$, or
$\alpha_{s}(M_{Z}) = 0.110 \pm 0.001 \pm 0.007$.


title:
Search for a Fourth Generation Charge -1/3 Quark via Flavor Changing
  Neutral Current Decay

abstract:
  We report on a search for pair production of a fourth generation charge -1/3
quark (b') in pbar p collisions at sqrt(s) = 1.8 TeV at the Fermilab Tevatron
using an integrated luminosity of 93 pb^-1. Both quarks are assumed to decay
via flavor changing neutral currents (FCNC). The search uses the signatures
gamma + 3 jets + mu-tag and 2 gamma + 2 jets. We see no significant excess of
events over the expected background. We place an upper limit on the production
cross section times branching fraction that is well below theoretical
expectations for a b' quark decaying exclusively via FCNC for b' quark masses
up to m(Z) + m(b).


title: Accurate Measurement of F2d/F2p and Rd-Rp

abstract:
  Results are presented for F2d/F2p and Rd-Rp from simultaneous measurements of
deep inelastic muon scattering on hydrogen and deuterium targets, at 90, 120,
200 and 280 GeV. The difference Rd-Rp, determined in the range 0.002<x<0.4 at
an average Q^2 of 5 GeV^2, is compatible with zero. The x and Q^2 dependence of
F2d/F2p was measured in the kinematic range 0.001<x<0.8 and 0.1<Q^2<145 GeV^2
with small statistical and systematic errors. For x>0.1 the ratio decreases
with Q^2.


title: Tests of QCD at low $x$

abstract:
  This talk reviews the latest measurements of the proton, Pomeron and photon
structure functions. These measurements, especially at low $x$ and/or low $Q^2$
lead to new insight into the picture of hadronic interactions.


title:
Limits on Anomalous $WW\gamma$ Couplings from $p\bar{p} \to W \gamma +
  X$ Events at $\sqrt{s}=1.8$ TeV

abstract:
  We have measured the $WW\gamma$ gauge boson coupling parameters using
$p\bar{p}\to \ell\nu\gamma+X$ ($\ell=e,\mu$) events at $\sqrt{s}=1.8$ TeV. The
data, corresponding to an integrated luminosity of 89.1 pb^{-1}, were collected
using the D0 detector at the Fermilab Tevatron Collider. The measured cross
section times branching ratio for $p\bar{p} \to W\gamma+X$ with $p_T^\gamma$ >
10 GeV/c and $R_{\ell\gamma} > 0.7$ is ${11.8}^{+1.7}_{-1.6} \pm 2.0$ pb, in
agreement with the Standard Model prediction. The one degree of freedom 95%
confidence level limits on individual CP-conserving parameters are
$-0.98<\Delta\kappa<1.01$ and $-0.33<\lambda<0.31$. Similar limits are set on
the CP}violating coupling parameters.


title: QCD: Challenges for the Future

abstract:
  Despite many experimental verifications of the correctness of our basic
understanding of QCD, there remain numerous open questions in strong
interaction physics and we focus on the role of future colliders in addressing
these questions. We discuss possible advances in the measurement of $\alpha_s$,
in the study of parton distribution functions, and in the understanding of low
$x$ physics at present colliders and potential new facilities. We also touch
briefly on the role of spin physics in advancing our understanding of QCD.


title:
A Study of Cosmic Ray Composition in the Knee Region using Multiple Muon
  Events in the Soudan 2 Detector

abstract:
  Deep underground muon events recorded by the Soudan 2 detector, located at a
depth of 2100 meters of water equivalent, have been used to infer the nuclear
composition of cosmic rays in the "knee" region of the cosmic ray energy
spectrum. The observed muon multiplicity distribution favors a composition
model with a substantial proton content in the energy region 800,000 -
13,000,000 GeV/nucleus.


title: Search for CP Violation in Charged D Meson Decays

abstract:
  We report results of a search for CP violation in the singly
Cabibbo-suppressed decays D+ -> K- K+ pi+, phi pi+, K*(892)0 K+, and pi- pi+
pi+ based on data from the charm hadroproduction experiment E791 at Fermilab.
We search for a difference in the D+ and D- decay rates for each of the final
states. No evidence for a difference is seen. The decay rate asymmetry
parameters A(CP), defined as the difference in the D+ and D- decay rates
divided by the sum of the decay rates, are measured to be: A(CP)(K K pi) =
-0.014 +/- 0.029, A(CP)(phi pi) = -0.028 +/- 0.036, A(CP)(K*(892) K) = -0.010
+/- 0.050, and A(CP)(pi pi pi) = -0.017 +/- 0.042.