title: High Transverse Momentum Physics at the Large Hadron Collider

abstract:
  This note summarizes the various physics studies done for the LHC. It
concentrates on the processes involving the production of high mass states.
Results are drawn from simulations performed by the CMS and ATLAS
collaborations. The ability of the LHC to provide insight into the mechanism of
electroweak symmetry breaking is exemplified.


title: Review of alpha-s Measurements

abstract:
  Determinations of alpha_s are reviewed. Current results are limited to a
precision of around 3-20%, largely by theoretical uncertainties. All
measurements are consistent with a `world average' value of 0.118 +- 0.005 and
there is no evodence of any discrepancy between `low-Q^2' and `high-Q^2'
results.


title:
Determination of alpha_s(M_Z^2) from hadronic event shape observables in
  e+e- annihilation

abstract:
  The determination of alpha_s(M_Z^2) using O(alpha_s^2) calculations of
hadronic event observables in e+e- annihilation is reviewed. The large scatter
among alpha_s(M_Z^2) values determined from different observables may be
interpreted as arising from the effect of uncalculated higher-order
contributions. The application of `optimised' perturbation theory and Pade
approximants in an attempt to reduce this effect is discussed.


title: Search for Top Squark Pair Production in the Dielectron Channel

abstract:
  This report describes the first search for top squark pair production in the
channel stop_1 stopbar_1 -> b bbar chargino_1 chargino_1 -> ee+jets+MEt using
74.9 +- 8.9 pb^-1 of data collected using the D0 detector. A 95% confidence
level upper limit on sigma*B is presented. The limit is above the theoretical
expectation for sigma*B for this process, but does show the sensitivity of the
current D0 data set to a particular topology for new physics.


title: Time Dependent B0 B0-bar Mixing at CDF

abstract:
  We describe two measurements of Delta m_d. The first uses B -> nu l D(*)
events and a same-side flavor tagging algorithm. The second uses dilepton
events. From the average of these two measurements we find Delta m_d = 0.466 +-
0.037 +- 0.031 ps^{-1}.


title:
Search for Diphoton Events with Large Missing Transverse Energy in
  proton-antiproton collisions at sqrt(s) = 1.8 TeV

abstract:
  A search for signals of new physics has been carried out in the channel p
pbar -> gamma gamma + ETmiss. This signature is expected in various recently
proposed supersymmetric (SUSY) models. We observe 842 events with two photons
having transverse momentum ET(g) > 12 GeV and pseudorapidity |eta(g)| < 1.1. Of
these, none have missing transverse energy (ETmiss) in excess of 25 GeV. The
distribution of ETmiss is consistent with that of the expected background. We
therefore set limits on production cross sections for selectron, sneutrino and
neutralino pairs, decaying into photons. The limits range from about 400 fb to
1 pb depending on the sparticle masses. A general limit of 185 fb (95% C.L.) is
set on sigma.B(pbar p -> gamma gamma ETmiss + X) where ET(g) > 12 GeV, |eta(g)|
< 1.1, and ETmiss > 25 GeV.


title: Prospects for the Precision Measurement of Alpha_S

abstract:
  The prospects for the measurement of the strong coupling constant
alpha_msbar(M_Z) to a relative uncertainty of 1% are discussed. Particular
emphasis is placed on the implications relating to future High Energy Physics
facilities.


title:
Identification of a sample of e+e- -> qq Events For the Precise
  Measurement of Alpha_S in High Energy Electron Positron Colliders

abstract:
  Based on the PYTHIA physics simulation package, and a fast simulation of the
proposed detector for the Next Linear Collider, a set of cuts is identified
which leads to a sample of e+e- -> qq events appropriate for the precise
measurement of alpha_s in e+e- annihilation at sqrt(s) = 500 GeV/c^2. Using
these cuts, the systematic uncertainty on alpha_s associated with correcting
for selection cut biases and remaining non-e+e- -> qq (q ^= t) contamination is
expected to be less than +/- 1%. This work was done as part of a study of the
prospects for the precise measurement of alpha_s at future High Energy Physics
facilities, undertaken for the 1996 Snowmass Workshop on New Directions in High
Energy Physics.


title: A Superheated Droplet Detector for Dark Matter Search

abstract:
  We discuss the operation principle of a detector based on superheated
droplets of Freon-12 and its feasibility for the search of weakly interacting
cold dark matter particles. In particular we are interested in a neutralino
search experiment in the mass range from 10 to 10^4 GeV/c^2 and with a
sensitivity of better than 10^-2 events/kg/d. We show that our new proposed
detector can be operated at ambient pressure and room temperature in a mode
where it is exclusively sensitive to nuclear recoils like those following
neutralino interactions, which allows a powerful background discrimination. An
additional advantage of this technique is due to the fact that the detection
material, Freon-12, is cheap and readily available in large quantities.
Moreover we were able to show that piezoelectric transducers allow efficient
event localization in large volumes.


title:
Nuclear Attenuation of Fast Hadrons Produced in Charged-Current Neutrino
  and Antineutrino Interactions in Neon

abstract:
  The production of hadrons in charged-current (anti)neutrino interactions is
studied with the bubble chamber BEBC exposed ot the CERN (anti)neutrino
wide-band beam. Fast-hadron production in a neon target is found to be
attennuated as compared to that in a hydrogen target. This feature is discussed
within the theoretical models based on the idea of a hadron formation length.
The experimental results favour the `constituent' over the `yo-yo' length
concept, and suggest a quark cross-section in the order of 3mb.


title:
Correlations in transverse momentum in pion-proton and kaon-proton
  collisions at 250 GeV/c

abstract:
  We have measured the second-order normalized differential factorial moments
as a function of the difference of transverse momentum ($\Delta p_T$) in $\p^+
p$ and $K^+ p$ collisions at 250 GeV/$c$. The second-order differential
factorial moments for like-charged pairs reveal a strong increase with
decreasing $\Delta p_T$. In a small central rapidity window this increase is
described by a simple power law. Such a behavior, if interpreted as originating
from Bose-Einstein correlations, may indicate a structure of the transverse
spatial distribution of the source similar to that recently predicted by
Bia\l{}as and Peschanski for color-dipole emission in onium-onium scattering.
The power of the rise obtained in the fit agrees with the predicted value.


title: Experimental Aspects of the Standard Model: A Short Course for Theorists

abstract:
  This is a series of lectures intended to introduce high energy theorists to
the marvels of the Standard Model from an experimentalist's point of view.


title: Status of the Strong Coupling Constant

abstract:
  The current status of measurements of the strong coupling constant from
different reactions is reviewed. Including new results presented at the 1996
ICHEP conference, a global average alpha_s(Mz) = 0.118 +- 0.003 is obtained.


title: A search for the rare decay K+ -> pi+ nu nu

abstract:
  Recent results from the first phase of the E787 experiment and an update on
the current status are presented. From the first phase the limit on the K+ ->
pi+ nu nu (pnn) branching ratio is BR(pnn) < 2.4e-9 (90%CL). An observation of
the decay K+ -> pi+ mu mu has been made using two separate techniques. An
observation of the decay K+ -> pi+ gamma gamma has been made and the
distribution of two photon invariant mass is inconsistent with phase space but
consistent with chiral perturbation theory.
  A description of recent upgrades to the detector follows. With the upgraded
detector the pnn decay should soon be observable. A discussion of the expected
sensitivity for pnn during the current running period is presented. Possible
improvements, in order to make a significant measurement of |Vtd|, are
discussed. One result from the upgraded detector is a measurement of the
structure dependent part (SD+) of the decay K+ -> mu+ nu gamma with a branching
ratio of BR(SD+) = (1.33 +/- 0.12 +/- 0.18)e-5.


title:
Measurement of the Proton and Deuteron Spin Structure Function g_1 in
  the Resonance Region

abstract:
  We have measured the proton and deuteron spin structure functions g_1^p and
g_1^d in the region of the nucleon resonances for W^2 < 5 GeV^2 and $Q^2\simeq
0.5$ and $Q^2\simeq 1.2$ GeV^2 by inelastically scattering 9.7 GeV polarized
electrons off polarized $^{15}NH_3$ and $^{15}ND_3$ targets. We observe
significant structure in g_1^p in the resonance region. We have used the
present results, together with the deep-inelastic data at higher W^2, to
extract $\Gamma(Q^2)\equiv\int_0^1 g_1(x,Q^2) dx$. This is the first
information on the low-Q^2 evolution of Gamma toward the Gerasimov-Drell-Hearn
limit at Q^2 = 0.


title: Test of QCD Analytic Predictions for Gluon and Quark Jet Differences

abstract:
  Differences between the properties of gluon and quark jets have been
convincingly established by experiments at LEP. Quantitative tests of QCD
analytic predictions for these differences have not been possible, however,
because of differences between the theoretical and experimental definitions of
the jets and event samples. Here, a new method to compare gluon and quark jet
properties is described, which uses an inclusive definition of the jets in
analogy to theoretical calculations. Using this new method, a value
1.552+-0.041(stat.)+-0.061(syst.) is found for the ratio of the mean charged
particle multiplicity in gluon jets to that in quark jets, in agreement with a
recent analytic calculation which incorporates energy conservation.


title:
Study of Gluon versus Quark Fragmentation in $\Upsilon\to gg\gamma$ and
  $e^{+}e^{-}\to q\bar{q}\gamma$ Events at \sqrt{s}=10 GeV

abstract:
  Using data collected with the CLEO II detector at the Cornell Electron
Storage Ring, we determine the ratio R(chrg) for the mean charged multiplicity
observed in Upsilon(1S)->gggamma events, to the mean charged multiplicity
observed in e+e- -> qqbar gamma events. We find R(chrg)=1.04+/-0.02+/-0.05 for
jet-jet masses less than 7 GeV.


title:
Conceptual Study of an ``Anti-Tagged'' Experiment Searching for
  muon-neutrino --> electron-neutrino Oscillation

abstract:
  We study the conceptual feasibility of a high energy, ``short baseline'',
zero background experiment to search for muon-neutrino --> electron-neutrino
oscillations and fully covering the area where the LSND experiment claims
evidence. The natural electron-neutrino background of the muon-neutrino beam,
from K and mu decays in the decay tunnel, is suppressed by a hadron blind
detector that vetoes, by time coincidence, a possible electron-neutrino signal
in the neutrino detector (anti-tagging technique). We discuss this new idea and
we study a possible implementation in the old neutrino line of the PS
accelerator, which at CERN offers the ideal $L/E$ ratio. In the anti-tagged
muon-neutrino beam, the electron-neutrino contamination can be reduced by more
than two orders of magnitude over conventional beams, down to 5*10^{-5}. In an
ideal appearance experiment using a 300 t detector one would expect after two
years 112 events according to the LSND result, with a background of 1.1-2.4
events. In case of a negative search, the 90% C.L. upper limit in the mixing
angle would be sin^2 < 1.8*10^{-4}$ for large Delta(m^2) and Delta(m^2)
<3.3*10^{-2} eV^2 for maximal mixing.


title: Analyses of $D^+\to K_S^0 K^+$ and $D^+\to K_S^0 \pi^+$

abstract:
  Using data collected with the CLEO II detector at the Cornell Electron
Storage Ring, we present new measurements of the branching fractions for $D^+
\to K_S K^+$ and $D^+ \to K_S \pi^+$. These results are combined with other
CLEO measurements to extract the ratios of isospin amplitudes and phase shifts
for $D \to KK$ and $D \to K\pi$.


title: Searches for New Physics at the Tevatron

abstract:
  This paper summarizes searches at the Fermilab Tevatron for a wide variety of
signatures for physics beyond the Standard Model. These include searches for
supersymmetric particles, in the two collider detectors and in one fixed target
experiment. Also covered are searches for leptoquarks, dijet resonances, heavy
gauge bosons, and particles from a fourth generation, as well as searches for
deviations from the Standard Model predictions in dijet angular distributions,
dilepton mass distributions, and trilinear gauge boson couplings.


title:
A Precision Measurement of Electroweak Parameters in Neutrino-Nucleon
  Scattering

abstract:
  The CCFR collaboration reports a precise measurement of electroweak
parameters derived from the ratio of neutral-current to charged-current
cross-sections in neutrino-nucleon scattering at the Fermilab Tevatron. This
ratio of cross-sections measures the neutral current couplings to quarks, which
implies a determination of sin^2 theta_W (on-shell) = 0.2236 +/- 0.0028(expt.)
+/- 0.0030(model) for m_top=175 GeV, m_Higgs=150 GeV. This is equivalent to
M_W=80.35+/-0.21 GeV. The good agreement of this measurement with Standard
Model expectations implies the exclusion of additional
neutrino-neutrino-quark-quark contact interactions at 95% confidence at a mass
scale of 1-8 TeV, depending on the form of the contact interaction.


title: Radiation studies for GaAs in the ATLAS Inner Detector

abstract:
  We estimate the hardness factors and the equivalent 1 MeV neutron fluences
for hadrons fluences expected at the GaAs positions wheels in the ATLAS Inner
Detector. On this basis the degradation of the GaAs particle detectors made
from different substrates as a function of years LHC operation is predicted.


title: Tau Neutrino Helicity from $h^{\pm}$ Energy Correlations

abstract:
  We report a measurement of the magnitude of the tau neutrino helicity from
tau-pair events taken with the CLEO detector at the CESR electron-positron
storage ring. Events in which each tau undergoes the decay tau -> h nu, with h
a charged pion or kaon, are analyzed for energy correlations between the
daughter hadrons, yielding |xi| = 2*|h_nu| = 1.03 +/- 0.06 +/- 0.04, with the
first error statistical and the second systematic.


title: $\Lambda\bar{\Lambda}$ Production in Two-Photon Interactions at CLEO

abstract:
  Using the CLEO detector at the Cornell $e^+e^-$ storage ring, CESR, we study
the two-photon production of $\Lambda \bar{\Lambda}$, making the first
observation of $\gamma \gamma \to \Lambda \bar{\Lambda}$. We present the
cross-section for $ \gamma \gamma \to \Lambda \bar{\Lambda}$ as a function of
the $\gamma \gamma$ center of mass energy and compare it to that predicted by
the quark-diquark model.


title: Progress in Understanding Heavy Flavor Decays

abstract:
  I review new results on particles containing a charm or bottom quark,
focusing on measurements that give insight into the dynamics of the decay
process. Leptonic and semileptonic decays are the simplest modes, and they
provide detailed tests of theoretical predictions based on methods such as
lattice QCD, heavy quark effective theory, and QCD sum rules. Although hadronic
decays are much more complicated, the factorization hypothesis makes
predictions that, at least for certain processes, are in accord with
measurements. I also emphasize the importance of precise measurements of
branching fractions for normalizing modes, whose uncertainties propagate into
many other quantities. Rare hadronic decays are now becoming accessible to
several experiments, and I discuss new results and their implications. Finally,
I review b-hadron lifetime measurements, which are steadily improving in
precision and which indicate a significant difference between B-meson and
b-baryon lifetimes.


title: Design and Test of a Forward Neutron Calorimeter for the ZEUS Experiment

abstract:
  A lead scintillator sandwich sampling calorimeter has been installed in the
HERA tunnel 105.6 m from the central ZEUS detector in the proton beam
direction. It is designed to measure the energy and scattering angle of
neutrons produced in charge exchange ep collisions. Before installation the
calorimeter was tested and calibrated in the H6 beam at CERN where 120 GeV
electrons, muons, pions and protons were made incident on the calorimeter. In
addition, the spectrum of fast neutrons from charge exchange proton-lucite
collisions was measured. The design and construction of the calorimeter is
described, and the results of the CERN test reported. Special attention is paid
to the measurement of shower position, shower width, and the separation of
electromagnetic showers from hadronic showers. The overall energy scale as
determined from the energy spectrum of charge exchange neutrons is compared to
that obtained from direct beam hadrons.


title:
Time Resolution and Linearity Measurements for a Scintillating Fiber
  Detector Instrumented with VLPC's

abstract:
  The time resolution for a charged particle detection is reported for a
typical scintillating fiber detector instrumented with Rockwell HISTE-IV
Visible Light Photon Counters. The resolution measurements are shown to agree
with a simple Monte Carlo model, and the model is used to make recomendations
for improved performance. In addition, the gain linearity of a sample of VLPC
devices was measured. The gain is shown to be linear for incident light
intensities which produce up to approximately 600 photoelectrons per event.


title:
An Improved Determination of $\alpha_{S}$ From Neutrino-Nucleon
  Scattering

abstract:
  We present an improved determination of the proton structure functions
$F_{2}$ and $xF_{3}$ from the CCFR $\nu $-Fe deep inelastic scattering (DIS)
experiment. Comparisons to high-statistics charged-lepton scattering results
for $F_{2}$ from the NMC, E665, SLAC, and BCDMS experiments, after correcting
for quark-charge and heavy-target effects, indicate good agreement for $x>0.1$
but some discrepancy at lower x. The $Q^{2}$ evolution of the structure
functions yields the quantum chromodynamics (QCD) scale parameter
$\Lambda_{\bar{MS}}^{NLO,(4)}=337 \pm 28$(exp.) MeV. This corresponds to a
value of the strong coupling constant at the scale of mass of the Z-boson of
$\alpha _{S}(M_{Z}^{2})=0.119 \pm 0.002 (exp.) \pm 0.004 (theory)$ and is one
of the most precise measurements of this quantity.


title: Analysis of Trapping and Detrapping in Semi-Insulating GaAs Detectors

abstract:
  To investigate the trapping and detrapping in SI-GaAs particle detectors we
analyzed the signals caused by 5.48 MeV alpha particles with a charge sensitive
preamplifier. From the bias and temperature dependence of these signals we
determine the activation energies of two electron traps. Additional simulation
and measurements of the lifetime as a function of resistivity have shown that
the EL2+ is the dominant electron trap in semi-insulating GaAs.


title: Heavy Flavour Physics - From Top to Bottom

abstract:
  We review the status of heavy flavour physics at the Fermilab Tevatron
collider by summarizing recent top quark and B physics results from CDF and DO.
In particular we discuss the measurement of the top quark mass and top
production cross section as well as B meson lifetimes and time dependent BB=
mixing results. An outlook of perspectives for top and B physics in Run II
starting in 1999 is also given.


title:
Measurement of the Tau Neutrino Helicity and the Michel Parameters in
  Polarized e+e- Collisions

abstract:
  We present a new measurement of the tau neutrino helicity, hnu and the tau
Michel parameters rho, eta, xi and the product delta xi. The analysis exploits
the highly polarized SLC electron beam to extract these quantities directly
from a measurement of the tau decay spectra, using the 1993-1995 SLD data
sample of 4328 e+e- --> Z0 --> tau+tau- events. From the decays tau --> pi
nu(tau) and tau --> rho nu(tau) we obtain a combined value
hnu=-0.93+/-0.10+/-0.04. The leptonic decay channels yield combined values of
rho=0.72+/-0.09+/-0.03, xi=1.05+/-0.35+/-0.04 and delta xi=0.88+/-0.27+/-0.04.


title: Measurement of the B+ and B0 Lifetimes from Semileptonic Decays

abstract:
  The lifetimes of B+ and B0 mesons are measured using a sample of 150,000
hadronic Z0 decays collected by the SLD experiment at the SLC between 1993 and
1995. The analysis identifies the semileptonic decays of B mesons and
reconstructs the B meson decay length and charge by vertexing the lepton with a
partially reconstructed D meson. This new method results in a sample of 634
(584) charged (neutral) decays with high charge purity. The ratio of B+ : B0
decays in the charged (neutral) sample is 3:1 (1:3). A maximum likelihood fit
yields t(B+) = 1.61 +0.13 -0.12(stat) +/- 0.07(syst) ps, t(B0) = 1.56 +0.14
-0.13(stat) +/- 0.10(syst) ps, and t(B+)/t(B0) = 1.03 +0.16 -0.14(stat) +/-
0.09(syst).


title: Measurement of the B+ and B0 Lifetimes using Topological Vertexing

abstract:
  The lifetimes of B+ and B0 mesons have been measured using a sample of
150,000 hadronic Z0 decays collected by the SLD experiment at the SLC between
1993 and 1995. The analysis reconstructs the decay length and charge of the B
meson using a novel topological vertexing technique. This method results in a
high statistics sample of 6033 (3665) charged (neutral) vertices with good
charge purity. A maximum likelihood fit procedure finds: t(B+) = 1.67 +/-
0.07(stat) +/- 0.06(syst) ps, t(B0) = 1.66 +/- 0.08(stat) +/- 0.08(syst) ps,
t(B+)/t(B0) = 1.01 +0.09-0.08(stat) +/- 0.05(syst).


title: Diffraction Dissociation in Photoproduction at HERA

abstract:
  A study is presented of the process gamma p -->XY, where there is a large
rapidity gap between the systems X and Y. Measurements are made of the
differential cross section as a function of the invariant mass mx of the system
produced at the photon vertex. Results are presented at centre of mass energies
of W_gp = 187 GeV and W_gp = 231 GeV, both where the proton dominantly remains
intact and, for the first time, where it dissociates. Both the centre of mass
energy and the mx^2 dependence of HERA data and those from a fixed target
experiment may simultaneously be described in a triple-Regge model. The low
mass photon dissociation process is found to be dominated by diffraction,
though a sizable subleading contribution is present at larger masses. The
pomeron intercept is extracted and found to be alpha_pom(0) = 1.068 \pm 0.016
(stat.) \pm 0.022 (syst.) \pm 0.041 (model), in good agreement with values
obtained from total and elastic hadronic and photoproduction cross sections.
The diffractive contribution to the process gamma p --> Xp with mx^2 / W_gp^2 <
0.05 is measured to be 22.2 \pm 0.6 (stat.) \pm 2.6 (syst.) \pm 1.7 (model) %
of the total gamma p cross section at W_gp = 187 GeV.


title: Search for New Particles Decaying to Dijets at CDF

abstract:
  We have used 106 pb^-1 of data collected with the Collider Detector at
Fermilab to search for new particles decaying to dijets. We exclude at the 95%
confidence level models containing the following new particles: axigluons and
flavor universal colorons with mass between 200 and 980 GeV/c, excited quarks
with mass between 80 and 570 GeV/c^2 and between 580 and 760 GeV/c^2, color
octet technirhos with mass between 260 and 480 GeV/c^2, W' bosons with mass
between 300 and 420 GeV/c^2, and E_6 diquarks with mass between 290 and 420
GeV/c^2.


title:
Spin Structure of the Proton from Polarized Inclusive Deep-Inelastic
  Muon-Proton Scattering

abstract:
  We have measured the spin-dependent structure function $g_1^p$ in inclusive
deep-inelastic scattering of polarized muons off polarized protons, in the
kinematic range $0.003 < x < 0.7$ and $1 GeV^2 < Q^2 < 60 GeV^2$. A
next-to-leading order QCD analysis is used to evolve the measured
$g_1^p(x,Q^2)$ to a fixed $Q^2_0$. The first moment of $g_1^p$ at $Q^2_0 = 10
GeV^2$ is $\Gamma^p = 0.136\pm 0.013(stat.) \pm 0.009(syst.)\pm 0.005(evol.)$.
This result is below the prediction of the Ellis-Jaffe sum rule by more than
two standard deviations. The singlet axial charge $a_0$ is found to be $0.28
\pm 0.16$. In the Adler-Bardeen factorization scheme, $\Delta g \simeq 2$ is
required to bring $\Delta \Sigma$ in agreement with the Quark-Parton Model. A
combined analysis of all available proton and deuteron data confirms the
Bjorken sum rule.


title:
Study of KS KL Coupled Decays and KL -Be Interactions with the CMD-2
  Detector at VEPP-2M Collider

abstract:
  The integrated luminosity about 4000 inverse nanobarn of around phi meson
mass ( 5 millions of phi mesons) has been collected with the CMD-2 detector at
the VEPP-2M collider. A latest analysis of the KS KL coupled decays based on 30
% of available data is presented in this paper.
  The KS KL pairs from phi meson decays were reconstructed in the drift chamber
when both kaons decayed into two charged particles. From a sample of 1423
coupled decays a selection of candidates to the CP violating KL into pi+ pi-
decay was performed. CP violating decays were not identified because of the
domination of events with a KL regenerating at the Be beam pipe into KS and a
background from KL semileptonic decays.
  The regeneration cross section of 110 MeV/c KL mesons was found to be 53 +-
17 mb in agreement with theoretical expectations. The angular distribution of
KS mesons after regeneration and the total cross section of KL for Be have been
measured.


title:
Study of the B^0 Semileptonic Decay Spectrum at the Upsilon(4S)
  Resonance

abstract:
  We have made a first measurement of the lepton momentum spectrum in a sample
of events enriched in neutral B's through a partial reconstruction of B0 -->
D*- l+ nu. This spectrum, measured with 2.38 fb**-1 of data collected at the
Upsilon(4S) resonance by the CLEO II detector, is compared directly to the
inclusive lepton spectrum from all Upsilon(4S) events in the same data set.
These two spectra are consistent with having the same shape above 1.5 GeV/c.
From the two spectra and two other CLEO measurements, we obtain the B0 and B+
semileptonic branching fractions, b0 and b+, their ratio, and the production
ratio f+-/f00 of B+ and B0 pairs at the Upsilon(4S). We report b+/b0=0.950
(+0.117-0.080) +- 0.091, b0 = (10.78 +- 0.60 +- 0.69)%, and b+ = (10.25 +- 0.57
+- 0.65)%. b+/b0 is equivalent to the ratio of charged to neutral B lifetimes,
tau+/tau0.


title: Detection of the RF Pulse Associated With Cosmic Ray Air Showers

abstract:
  Initial results of a project to detect the radio-frequency pulse associated
with extensive air showers of cosmic rays are described briefly. This work is
being performed at the CASA/MIA array in Utah, with the intention of designing
equipment that can be used in conjunction with the Auger Giant Array proposal.


title:
Measurement of Leading Particle Effects in Decays of Z0 Bosons into
  Light Flavors

abstract:
  We present evidence for leading particle production in hadronic decays of the
Z0 boson to light-flavor jets. A polarized electron beam was used to tag quark
and antiquark jets, and a vertex detector was employed to reject heavy-flavor
events. Charged hadrons were identified with a Cherenkov ring imaging detector.
In the quark jets, more high-momentum p, Lambda, K-, and anti-K*0 were observed
than their antiparticles, and vice versa for antiquark jets, providing direct
evidence that the higher-momentum particles in jets are more likely to carry
the primary quark or antiquark from the Z0 decay, and that s-s(bar) production
is suppressed in fragmentation.


title: Spin-Parity Analysis of the Centrally produced KsKs system at 800 GeV

abstract:
  Results are presented of the spin-parity analysis on a sample of centrally
produced mesons in the reaction (p p -> p_{slow} K_s K_s p_{fast}) with 800 GeV
protons on liquid hydrogen. The spin-parity analysis in the mass region between
threshold and 1.58 GeV/c^2 shows that the (K_s K_s) system is produced mainly
in S-wave. The f_0(1500) is clearly observed in this region. Above 1.58 GeV/c^2
two solutions are possible, one with mainly S-wave and another with mainly
D-wave. This ambiguity prevents a unique determination of the spin of the
f_J(1710) meson.


title:
Study of the ZZ\gamma and Z\gamma\gamma Couplings in Z(\nu\nu)\gamma
  Production

abstract:
  We have measured the ZZ-gamma and Z-gamma-gamma couplings by studying p-bar p
-> (missing ET) gamma + X events at sqrt(s)=1.8 TeV with the D0 detector at the
Fermilab Tevatron Collider. This first study of hadronic Z-gamma production in
the neutrino decay channel gives the most stringent limits on anomalous
couplings available. A fit to the transverse energy spectrum of the photon in
the candidate event sample, based on a data set corresponding to an integrated
luminosity of 13.1 pb^(-1), yields 95% CL limits on the anomalous CP-conserving
ZZ-gamma couplings of |h^Z_(30)|<0.9, |h^Z_(40)|<0.21, for a form-factor scale
Lambda = 500 GeV. Combining these results with our previous measurement using Z
-> ee and mu-mu yields the limits:|h^Z_(30)|<0.8, |h^Z_(40)|<0.19 (Lambda = 500
GeV) and |h^Z_(30)|<0.4, |h^Z_(40)|<0.06 (Lambda = 750 GeV).


title: Observation of Events at Very High Q^2 in ep Collisions at HERA

abstract:
  Measurements of ep scattering with squared 4-momentum transfer Q^2 up to
35000 GeV^2 are compared with the expectation of the standard deep-inelastic
model of lepton-nucleon scattering (DIS). For Q^2 > 15000 GeV^2, N_{obs} =12
neutral current candidate events are observed where the expectation is N_DIS =
4.71 \pm 0.76 events. In the same Q^2 range, N_{obs} =4 charged current
candidates are observed where the expectation is N_{DIS} = 1.77 \pm 0.87
events. The probability P(N \geq N_{obs}) that the DIS model signal N
fluctuates to N \geq N_{obs} in a random set of experiments is 6 10^{-3} for
neutral current and 0.14 for charged current. The difference in the observed
and expected number of Neutral Current events is mostly due to events at large
masses M = sqrt{xs} in which the positron is backscattered at large y =
Q^2/M^2.


title:
Measurement of the Decay Amplitudes and Branching Fractions of $B\to
  J/\psi K^{*}$ and $B\to J/\psi K$ Decays

abstract:
  Using data taken with the CLEO II detector, we present the first full angular
analysis in the color-suppressed modes B0 --> J/psi K*0 and B+ --> J/psi K*+.
This leads to a complete determination of the decay amplitudes of these modes.
In addition, we update the branching fractions for B --> J/psi K and B -->
J/psi K*.


title:
Production of charm mesons at high transverse momentum in 515 GeV/c pi-
  nucleon collisions

abstract:
  We present results on the production of high transverse momentum charm mesons
in collisions of 515 GeV/c negative pions with beryllium and copper targets.
The experiment recorded a large sample of events containing high transverse
momentum showers detected in an electromagnetic calorimeter. From these data, a
sample of charm mesons has been reconstructed via their decay into the fully
charged K pi pi mode. A measurement of the single inclusive transverse momentum
distribution of charged D mesons from 1 to 8 GeV/c is presented. An
extrapolation of the measured differential cross section yields an integrated
charged D cross section of 11.4+-2.7(stat)+-3.3(syst) microbarns per nucleon
for charged D mesons with Feynman x greater than zero. The data are compared
with expectations based upon next-to-leading order perturbative QCD, as well as
with results from PYTHIA. We also compare our integrated charged D cross
section with measurements from other experiments.


title:
Comparison of ZEUS Data with Standard Model Predictions for e^+ p -> e^+
  X Scattering at High x and Q^2

abstract:
  Using the ZEUS detector at HERA, we have studied the reaction e^+ p -> e^+ X
for Q^2 > 5000 GeV^2 with a 20.1 pb^{-1} data sample collected during the years
1994 to 1996. For Q^2 below 15000 GeV^2, the data are in good agreement with
Standard Model expectations. For Q^2 > 35000 Gev^2, two events are observed
while 0.145+-0.013 events are expected. A statistical analysis of a large
ensemble of simulated Standard Model experiments indicates that with
probability 6.0%, an excess at least as unlikely as that observed would occur
above some Q^2 cut. For x>0.55 and y>0.25, four events are observed where
0.91+-0.08 events are expected. A statistical analysis of the two-dimensional
distribution of the events in x and y yields a probability of 0.72% for the
region x>0.55 and y>0.25 and a probability of 7.8% for the entire Q^2 > 5000
GeV^2 data sample. The observed excess above Standard Model expectations is
particularly interesting because it occurs in a previously unexplored kinematic
region.


title: Signal Confidence Limits from a Neural Network Data Analysis

abstract:
  This paper deals with a situation of some importance for the analysis of
experimental data via Neural Network (NN) or similar devices: Let $N$ data be
given, such that $N=N_s+N_b$, where $N_s$ is the number of signals, $N_b$ the
number of background events, both unknown. Assume that a NN has been trained,
such that it will tag signals with efficiency $F_s$, $(0<F_s<1)$ and background
data with $F_b$, $(0<F_b<1)$. Applying the NN yields $N^Y$ tagged events. We
demonstrate that the knowledge of $N^Y$ is sufficient to calculate confidence
bounds for the signal likelihood, which have the same statistical
interpretation as the Clopper-Pearson bounds for the well-studied case of
direct signal observation. Subsequently, we discuss rigorous bounds for the
a-posteriori distribution function of the signal probability, as well as for
the (closely related) likelihood that there are $N_s$ signals in the data. We
compare them with results obtained by starting off with a maximum entropy type
assumption for the a-priori likelihood that there are $N_s$ signals in the data
and applying the Bayesian theorem. Difficulties are encountered with the latter
method.


title:
Pseudorapidity Distribution of Charged Particles in PbarP Collisions at
  root(s)= 630GeV

abstract:
  Using a silicon vertex detector, we measure the charged particle
pseudorapidity distribution over the range 1.5 to 5.5 using data collected from
PbarP collisions at root s = 630 GeV. With a data sample of 3 million events,
we deduce a result with an overall normalization uncertainty of 5%, and typical
bin to bin errors of a few percent. We compare our result to the measurement of
UA5, and the distribution generated by the Lund Monte Carlo with default
settings. This is only the second measurement at this level of precision, and
only the second measurement for pseudorapidity greater than 3.


title: Measurement of tau polarization in e+ e- annihilation at sqrt{s}=58 GeV

abstract:
  The polarization of tau leptons in the reaction e+ e- --> tau+ tau- has been
measured using a e+e- collider, TRISTAN, at the center-of-mass energy of 58
GeV. From the kinematical distributions of daughter particles in tau --> e nu
nu-bar, mu nu nu-bar, rho nu or pi(K) nu decays, the average polarization of
tau- and its forward-backward asymmetry have been evaluated to be 0.012 +-
0.058 and 0.029 +- 0.057, respectively.


title: Vector and Axial-Vector Spectral Functions and QCD

abstract:
  We present new results of the tau hadronic spectral function analysis using
data accumulated by the ALEPH detector at LEP during the years 1991-94. In
addition to the vector spectral functions, the axial-vector spectral functions
and, separately, the tau --> 3pi nu as well as the tau --> pi 2pi0 nu spectral
functions are determined from their respective unfolded, i.e., physical
invariant mass spectra. The spectral functions are applied to QCD chiral sum
rules in order to extract information about saturation at the tau mass scale.
Using the the semi-leptonic tau decay rate for vector and axial-vector currents
in addition to spectral moments, we obtain precise measurements of the strong
coupling constant alpha_s(M_tau) and the contributing non-perturbative power
terms. The evolution to the Z mass yields alpha_s(M_Z) = 0.1219 +/- 0.0019.


title:
Measurement of the Neutron Spin Structure Function $g_1^n$ with a
  Polarized ^3He Target

abstract:
  Results are reported from the HERMES experiment at HERA on a measurement of
the neutron spin structure function $g_1^n(x,Q^2)$ in deep inelastic scattering
using 27.5 GeV longitudinally polarized positrons incident on a polarized
$^3$He internal gas target. The data cover the kinematic range $0.023<x<0.6$
and $1 (GeV/c)^2 < Q^2 <15 (GeV/c)^2$. The integral $\int_{0.023}^{0.6}
g_1^n(x) dx$ evaluated at a fixed $Q^2$ of $2.5 (GeV/c)^2$ is $-0.034\pm
0.013(stat.)\pm 0.005(syst.)$. Assuming Regge behavior at low $x$, the first
moment $\Gamma_1^n=\int_0^1 g_1^n(x) dx$ is $-0.037\pm 0.013(stat.)\pm
0.005(syst.)\pm 0.006(extrapol.)$.


title: The Inclusive Decays $B\to D X$ and $B\to D^* X$

abstract:
  We report new measurements of the differential and total branching ratios for
inclusive B decay to D^0, D^+ and D^{*+} and the first measurement of the same
quantities for inclusive B decay to $D^{*0}$.
  Here B is the mixture of B_d and B_u from $\Upsilon(4S)$ decay. Furthermore,
since more than one charm particle (or antiparticle) of the same kind can be
produced in B decay, here ``inclusive B branching ratio'' is used to mean the
average number of charm particles and their antiparticles of a certain species
produced in B decay.
  We obtain the following results (the first error is statistical, the second
systematic of this analysis, the third is propagated from other measurements):
  ${\cal B}(B\to D^0 X) = (0.636\pm 0.014\pm 0.019\pm 0.018),
  {\cal B}(B\to D^+ X) = (0.235\pm 0.009\pm 0.009\pm 0.024),
  {\cal B}(B\to D^{*0} X) = (0.247\pm 0.012\pm 0.018\pm 0.018),
  {\cal B}(B\to D^{*+} X) = (0.239\pm 0.011\pm 0.014\pm 0.009)$.
  The following ratio of branching ratios is not affected by most of the
systematic errors: ${\cal B}(B\to D^{*0} X)/{\cal B}(B\to D^{*+} X) = (1.03\pm
0.07\pm 0.09\pm 0.08).$
  We also report the first measurement of the momentum-dependent $D^{*0}$
polarization and a new measurement of the $D^{*+}$ polarization in inclusive B
decay. Using these measurements and other CLEO results and making some
additional assumptions, we calculate the average number of c and $\bar c$
quarks produced in B decay to be $< n_c > = 1.10\pm 0.05$.


title:
Xi^- Production by Sigma^-, pi^- and Neutrons in the Hyperon Beam
  Experiment at CERN

abstract:
  Inclusive cross sections for Xi^- hyperon production in high-energy Sigma^-,
pi^- and neutron induced interactions were measured by the experiment WA89 at
CERN. Secondary Sigma^- and pi^- beams with average momenta of 345 GeV/c and a
neutron beam of average momentum 65 GeV/c were produced by primary protons of
450 GeV/c from the CERN SPS. Both single and double differential cross sections
are presented as a function of the transverse momentum and the Feynman variable
x_F. A strong leading effect for Xi^- produced by Sigma^- is observed. The
influence of the target mass on the Xi^- cross section is explored by comparing
reactions on copper and carbon nuclei.


title: Direct Measurement of the Top Quark Mass

abstract:
  We measure the top quark mass m_t using t tbar pairs produced in the D0
detector by root(s) = 1.8 TeV p pbar collisions in a 125 pb^-1 exposure at the
Fermilab Tevatron. We make a two constraint fit to m_t in t tbar --> b W^+ bbar
W^- final states with one W decaying to q qbar and the other to e nu or mu nu.
Events are binned in fit mass versus a measure of probability for events to be
signal rather than background. Likelihood fits to the data yield m_t = 173.3 +-
5.6 (stat) +- 6.2 (syst) GeV/c^2.


title:
Limit on the Two-Photon Production of the Glueball Candidate
  $f_{J}(2220)$ at CLEO

abstract:
  We use the CLEO detector at the Cornell electron-positron storage ring, CESR,
to search for the two-photon production of the glueball candidate f_J(2220) in
its decay to K_s K_s. We present a restrictive upper limit on the product of
the two-photon partial width and the K_s K_s branching fraction. We use this
limit to calculate a lower limit on the stickiness, which is a measure of the
two-gluon coupling relative to the two-photon coupling. This limit on
stickiness indicates that the f_J(2220) has substantial glueball content.


title: Observation of Diffractive W Boson Production at the Tevatron

abstract:
  We report the first observation of diffractively produced W bosons. In a
sample of W -> e nu events produced in p-barp collisions at sqrt{s}=1.8 TeV, we
find an excess of events with a forward rapidity gap, which is attributed to
diffraction. The probability that this excess is consistent with
non-diffractive production is 1.1 10^{-4} (3.8 sigma). The relatively low
fraction of W+Jet events observed within this excess implies that mainly quarks
from the pomeron, which mediates diffraction, participate in W production. The
diffractive to non-diffractive W production ratio is found to be R_W=(1.15 +/-
0.55)%.


title:
Development of High Pressure Xe Scintillation Proportional Counter for
  Experiments in "Low-Background" Physics

abstract:
  Characteristics of a scintillation proportional counter with WLS fiber optics
readout is described. The possibility of detection of the proportional
scintillation signal produced by the single electron of primary ionization is
shown. The counter can be applied for the experiments in "low--background"
physics which require a low energy threshold.


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

abstract:
  The results of a measurement of the proton structure function F_2(x,Q^2)and
the virtual photon-proton cross section are reported for momentum transfers
squared Q^2 between 0.35 GeV^2 and 3.5 GeV^2 and for Bjorken-x values down to 6
10^{-6} using data collected by the HERA experiment H1 in 1995. The data
represent an increase in kinematic reach to lower x and Q^2 values of about a
factor of 5 compared to previous H1 measurements. Including measurements from
fixed target experiments the rise of F_2 with decreasing x is found to be less
steep for the lowest Q^2 values measured. Phenomenological models at low Q^2
are compared with the data.


title:
Studies of the Cabbibo-Suppressed Decays $D^+ \to \pi^0 \ell^+ \nu$ and
  $D^+ \to \eta e^+ \nu_e$

abstract:
  Using 4.8 fb$^{-1}$ of data taken with the CLEO II detector, the branching
fraction for the Cabibbo-suppressed decay $D^+\to\pi^0\ell^+\nu$ measured
relative to the Cabibbo favored decay $D^+\to\bar{K^0}\ell^+\nu$ is found to be
$0.046\pm 0.014\pm 0.017$. Using $V_{cs}$ and $V_{cd}$ from unitarity
constraints, we determine $| f_+^{\pi}(0)/f_+^K(0)|^2=0.9\pm 0.3\pm 0.3$ We
also present a 90% confidence level upper limit for the branching ratio of the
decay $D^+ \to \eta e^+\nu_e$ relative to that for $D^+ \to \pi^0 e^+\nu_e$ of
1.5.


title: Deep inelastic scattering from unpolarised targets

abstract:
  In this paper the experimental status of unpolarised structure functions is
reviewed. In particular the latest results from the NMC, E665, CCFR, and HERA
experiments are discussed. Emphasis is put on the fixed-target experiments,
which cover with high precision the x region relevant for the present polarised
DIS experiments.


title:
Atomic mass dependence of \Xi^- and \overline{\Xi}^+ production in
  central 250 GeV \pi^- nucleon interactions

abstract:
  We present the first measurement of the atomic mass dependence of central
\Xi^- and \overline{\Xi}^+ production. It is measured using a sample of 22,459
\Xi^-'s and \overline{\Xi}^+'s produced in collisions between a 250 GeV \pi^-
beam and targets of beryllium, aluminum, copper, and tungsten. The relative
cross sections are fit to the two parameter function \sigma_0 A^\alpha, where A
is the atomic mass. We measure \alpha = 0.924+-0.020+-0.025, for Feynman-x in
the range -0.09 < x_F < 0.15.


title:
Bremsstrahlung Suppression due to the LPM and Dielectric Effects in a
  Variety of Materials

abstract:
  The cross section for bremsstrahlung from highly relativistic particles is
suppressed due to interference caused by multiple scattering in dense media,
and due to photon interactions with the electrons in all materials. We present
here a detailed study of bremsstrahlung production of 200 keV to 500 MeV
photons from 8 and 25 GeV electrons traversing a variety of target materials.
For most targets, we observe the expected suppressions to a good accuracy. We
observe that finite thickness effects are important for thin targets.


title:
Scintillation proportional Xe counter with WLS fiber readout for
  low-energy X-rays

abstract:
  A gas Xe based scintillation proportional counter with cylindrical geometry
and wavelength shifting (WLS) fiber readout for X-rays of energy 0.5 - 100 keV
is proposed. With such a design large sizes and sensitive area of the counter
with a fairly well uniformity is possible. The counter could be used for "dark
matter" search and neutrino magnetic moment measurement and for detection of
small amounts or traces of radioactive elements in substances or environment.


title: W Boson Physics at the Fermilab Tevatron

abstract:
  We present electroweak physics results from the D0 and CDF experiments using
data from p \bar p collisions at \sqrt s = 1.8 TeV. Measurements of the cross
sections times branching ratios for W and Z production, the inclusive width of
the W boson and the W boson mass are presented. Direct tests of the WW\gamma
and WWZ trilinear gauge boson couplings are also presented based on studies of
diboson production.


title:
Radiation damage to neutron and proton irradiated GaAs particle
  detectors

abstract:
  The radiation damage in 200 um thick Schottky diodes made on semi-insulating
(SI) undoped GaAs Liquid Encapsulated Czochralski (LEC) bulk material with
resistivities between 0.4 and 8.9*10E7 Ohm*cm were studied using
alpha-spectroscopy, signal response to minimum ionising particles (MIP), I-V
and CV-measurements. The results have been analysed to investigate the
influence of the substrate resistivity on the detector performance after
neutron and proton irradiation. The leakage current density, signal response to
alpha-particles and MIPs show a strong dependence on the resistivity before and
after irradiation. An observed decrease of the electron mean free drift length
before and after irradiation with increasing substrate resistivity can be
explained by a model involving the different ionisation ratios of defects,
which are introduced by the irradiation. Comparison of the radiation damage due
to neutrons and protons gives a hardness factor of 7+-0.9 for 24 GeV/c protons.
The best detectors show a response to MIPs of 5250 e- at 200 V reverse bias
after a irradiation level of 2*10E14 p/cm^2.


title:
Search For Charged Higgs Decays of the Top Quark Using Hadronic Decays
  of the Tau Lepton

abstract:
  This Letter describes a direct search for charged Higgs boson production in
proton-antiproton collisions at sqrt(s)=1.8 TeV recorded by the Collider
Detector at Fermilab. Two-Higgs-doublet extensions to the standard model
predict the existence of charged Higgs bosons. In such models, the branching
fraction for top quarks B(t --> H b --> tau nu b) can be large. This search
uses the hadronic decays of the tau lepton in this channel to significantly
extend previous limits on charged Higgs production.


title: Studies of Gauge Boson Pair Production and Trilinear Couplings

abstract:
  The gauge boson pair production processes Wg, WW, WZ, and Zg were studied
using pbarp collisions corresponding to an integrated luminosity of ~14 pb-1 at
a center-of-mass energy of sqrt(s) = 1.8 TeV. Analysis of Wg prod with
subsequent W boson decay to lv (l=e,mu) is reported, including a fit to the pT
spectrum of the photons which leads to limits on anomalous WWg couplings. A
search for WW prod with subsequent decay to l-lbar-v-vbar (l=e,mu) is presented
leading to an upper limit on the WW prod cross section and limits on anomalous
WWg and WWZ couplings. A search for high pT W bosons in WW and WZ prod is
described, where one W boson decays to an ev and the second W boson or the Z
boson decays to two jets. A maximum likelihood fit to the pT spectrum of W
bosons resulted in limits on anomalous WWg and WWZ couplings. A combined fit to
the three data sets which provided the tightest limits on anomalous WWg and WWZ
couplings is also described. Limits on anomalous ZZg and Zgg couplings are
presented from an analysis of the photon ET spectrum in Zg events in the decay
channels (ee, mu-mu, and v-vbar) of the Z boson.


title: Spin structure functions

abstract:
  The experimental status of the spin-dependent structure functions as obtained
from the deep inelastic scattering experiments at CERN, SLAC, and DESY is
reviewed. All data show a violation of the Ellis-Jaffe sum rule. The Bjorken
sum rule is found to be valid and is tested to the 10 % level.


title:
The Kinematics of Deep Inelastic Scattering in the Presence of Initial
  State Radiation

abstract:
  Initial state radiation (ISR) in deep inelastic scattering of charged leptons
on nucleons can lead to substantial shifts in the reconstruction of $Q^2$ and
the scaling variables $x$ and $y$. By measuring at least three out of the four
variables: energy and production angle of the lepton and the hadron system, the
energy of the ISR photon emitted under zero degrees can be determined. The ISR
effect is illustrated for experimentation at HERA with different methods of
kinematic reconstruction.


title:
The mu tau and e tau Decays of Top Quark Pairs Produced in p pbar
  Collisions at sqrt(s) = 1.8 TeV

abstract:
  We present evidence for dilepton events from t tbar production with one
electron or muon and one hadronically decaying tau lepton from the decay t tbar
-> (l nu_l) (tau nu_tau) b bbar, (l=e, mu), using the Collider Detector at
Fermilab (CDF). In a 109 pb^-1 data sample of p pbar collisions at sqrt(s) =
1.8 TeV we expect ~1 signal event and a total background of ~2 events; we
observe 4 candidate events (2 e tau and 2 mu tau). Three of these events have
jets identified as b candidates, compared to an estimated background of
0.28+-0.02 events.


title: Study of Photon Dissociation in Diffractive Photoproduction at HERA

abstract:
  Diffractive dissociation of quasi-real photons at a photon-proton centre of
mass energy of W ~ 200 GeV is studied with the ZEUS detector at HERA. The
process under consideration is gamma p -> X N, where X is the diffractively
dissociated photon system of mass M_X and N is either a proton or a nucleonic
system with mass M_N < 2GeV. The cross section for this process in the interval
3 < M_X < 24 GeV relative to the total photoproduction cross section was
measured to be sigma^partial_D / sigma_tot = 6.2 +- 0.2(stat) +- 1.4(syst)%.
After extrapolating this result to the mass interval of m_phi^2 < M_X^2 < 0.05
W^2 and correcting it for proton dissociation, the fraction of the total cross
section attributed to single diffractive photon dissociation, gamma p -> X p,
is found to be sigma_SD / sigma_tot = 13.3 +- 0.5(stat) +- 3.6(syst)%. The mass
spectrum of the dissociated photon system in the interval 8 < M_X < 24 GeV can
be described by the triple pomeron (PPP) diagram with an effective pomeron
intercept of alpha_P(0) = 1.12 +- 0.04(stat) +- 0.08(syst). The cross section
for photon dissociation in the range 3 < M_X < 8 GeV is significantly higher
than that expected from the triple pomeron amplitude describing the region 8 <
M_X < 24 GeV. Assuming that this discrepancy is due to a
pomeron-pomeron-reggeon (PPR) term, its contribution to the diffractive cross
section in the interval 3 < M_X < 24 GeV is estimated to be f_PPR = 26 +-
3(stat) +- 12(syst)%.


title:
Exclusive Production of Neutral Vector Mesons at the Electron-Proton
  Collider HERA

abstract:
  The first five years of operation of the multi-purpose experiments ZEUS and
H1 at the electron-proton storage ring facility HERA have opened a new era in
the study of vector-meson production in high-energy photon-proton interactions.
The high center-of-mass energy available at this unique accelerator complex
allows investigations in hitherto unexplored kinematic regions, providing
answers to long-standing questions concerning the energy-dependence of the rho,
omega, phi, and J/psi production cross sections. The excellent angular
acceptance of these detectors, combined with that of specialized tagging
detectors at small production angles, has permitted measurements of elastic and
inelastic production processes for both quasi-real photons and those of
virtuality exceeding the squared mass of the vector meson. This report provides
a quantitative picture of the present status of these studies, comparing them
to the extensive measurements in this field at lower energies and summarizing
topical developments in theoretical work motivated by the new data.


title:
Search for Neutrinoless $\tau$ Decays Involving $\pi^{0}$ or $\eta$
  Mesons

abstract:
  We have searched for lepton family number violating decays of the $\tau$
lepton using final states with an electron or a muon and one or more $\pi^0$ or
$\eta$ mesons but no neutrinos. The data used in the search were collected with
the CLEO II detector at the Cornell Electron Storage Ring (CESR) and correspond
to an integrated luminosity of 4.68 $fb^{-1}$. No evidence for signals was
found, resulting in much improved limits on the branching fractions for the
one-meson modes and the first upper limits for the two-meson modes.


title:
Differential Cross Sections of D*+- Photoproduction in ep Collisions at
  HERA

abstract:
  Inclusive photoproduction of D*+- in ep collisions at HERA has been measured
with the ZEUS detector for photon-proton centre of mass energies in the range
115 < W < 280 GeV and photon virtuality Q**2 < 4 GeV**2. The cross section
sigma(ep --> D*X) integrated over the kinematic region pt(D*) > 3 GeV and -1.5
< eta(D*) < 1.0 is (10.6+-1.7(stat.)+1.6(syst.)-1.3(syst.)) nb. Differential
cross sections as functions of pt(D*), eta(D*) and W are given. The data are
compared with two next-to-leading order perturbative QCD predictions. For a
calculation using a massive charm scheme the predicted cross sections are
smaller than the measured ones. A recent calculation using a massless charm
scheme is in agreement with the data.


title:
First Measurement of Leptonic Coupling Asymmetries with Polarized Z
  bosons

abstract:
  We present direct measurements of the $Z^0$-lepton coupling asymmetry
parameters, $A_e$, $A_\mu$, and $A_\tau$, based on a data sample of 12,063
leptonic $Z^0$ decays collected by the SLD detector. The $Z$ bosons are
produced in collisions of beams of polarized $e^-$ with unpolarized $e^+$ at
the SLAC Linear Collider. The couplings are extracted from the measurement of
the left-right and forward-backward asymmetries for each lepton species. The
results are: $A_e=0.152 \pm 0.012 {(stat)} \pm 0.001 {(syst)}$, $A_\mu=0.102
\pm 0.034 \pm 0.002$, and $A_\tau=0.195 \pm 0.034 \pm 0.003$.


title: Measurement of Elastic $J/\psi$ Photoproduction at HERA

abstract:
  The reaction gamma p -> J/Psi p has been studied in ep interactions using the
ZEUS detector at HERA. The cross section for elastic J/Psi photoproduction has
been measured as a function of the photon-proton centre of mass energy W in the
range 40 < W < 140 GeV at a median photon virtuality Q^2 of 5*10^{-5} GeV^2.
The photoproduction cross section, sigma_{gamma p -> J/Psi p}, is observed to
rise steeply with W. A fit to the data presented in this paper to determine the
parameter $\delta$ in the form sigma_{gamma p -> J/Psi p} \propto W^{\delta}
yields the value \delta = 0.92 \pm 0.14 \pm 0.10. The differential cross
section dsigma/d|t| is presented over the range |t| < 1.0 GeV^2 where t is the
square of the four-momentum exchanged at the proton vertex. d\sigma/d|t| falls
exponentially with a slope parameter of 4.6 \pm 0.4 (+0.4-0.6) GeV^{-2}. The
measured decay angular distributions are consistent with s-channel helicity
conservation.


title: Search for the Decays B^0 -> D^{(*)+} D^{(*)-}

abstract:
  Using the CLEO-II data set we have searched for the Cabibbo-suppressed decays
B^0 -> D^{(*)+} D^{(*)-}. For the decay B^0 -> D^{*+} D^{*-}, we observe one
candidate signal event, with an expected background of 0.022 +/- 0.011 events.
This yield corresponds to a branching fraction of Br(B^0 -> D^{*+} D^{*-}) =
(5.3^{+7.1}_{-3.7}(stat) +/- 1.0(syst)) x 10^{-4} and an upper limit of Br(B^0
-> D^{*+} D^{*-}) < 2.2 x 10^{-3} at the 90% CL. For B^0 -> D^{*\pm} D^\mp and
B^0 -> D^+ D^-, no significant excess of signal above the expected background
level is seen, and we calculate the 90% CL upper limits on the branching
fractions to be Br(B^0 -> D^{*\pm} D^\mp) < 1.8 x 10^{-3} and Br(B^0 -> D^+
D^-) < 1.2 x 10^{-3}.


title:
Measurement of the Top Quark Pair Production Cross Section in pbarp
  Collisions

abstract:
  We present a measurement of the ttbar production cross section in ppbar
collisions at root(s) = 1.8TeV by the D0 experiment at the Fermilab Tevatron.
The measurement is based on data from an integrated luminosity of approximately
125 pb^-1 accumulated during the 1992-1996 collider run. We observe 39 ttbar
candidate events in the dilepton and lepton+jets decay channels with an
expected background of 13.7+-2.2 events. For a top quark mass of 173.3GeV/c^2,
we measure the ttbar production cross section to be 5.5+-1.8 pb.


title: Review of the measurements of the strong coupling constant at LEP 2

abstract:
  Since 1995, LEP has steadily increased the center of mass energy of the
colliding beams, from the M_Z resonance to 133, 161 and 172 GeV. New
measurements of the strong coupling constant, alpha_s, at these energies have
been performed by the LEP experiments, L3, ALEPH, OPAL and DELPHI. In this
article, the new results are summarized, and combined with the previous LEP
measurement of alpha_s(M_Z) in order to obtain an updated LEP average of
alpha_s(M_Z) = 0.120 +- 0.005.


title: Status of weak quark mixing

abstract:
  The experimental status of the Cabibbo-Kobayashi-Maskawa matrix is reviewed.
Measurements discussed include B0_(s)-\bar{B}0_(s) mixing and several rare B
and K decays with implications for |V_td| and |V_ts|. Extraction of |V_cb| and
|V_ub| from studies of semileptonic B decay is also discussed.


title:
Search for Lepton Flavor Violation in ep Collisions at 300 GeV Center of
  Mass Energy

abstract:
  Using the ZEUS detector at the HERA electron-proton collider, we have
searched for lepton flavor violation in ep collisions at a center-of-mass
energy s^1/2 of 300 GeV. Events of the type e + p -> lepton + X with a
final-state lepton (mu or tau) of high transverse momentum, were sought. No
evidence was found for lepton flavor violation in the combined 1993 and 1994
data samples, for which the integrated luminosities were 0.84 pb^-1 for e- p
collisions and 2.94 pb^-1 for e+ p collisions. Limits on coupling vs. mass are
provided for leptoquarks and R-parity violating squarks. For flavor violating
couplings of electromagnetic strength, we set 95% confidence level lower limits
on leptoquark masses between 207 GeV and 272 GeV, depending on the leptoquark
species and final-state lepton. For leptoquark masses larger than 300 GeV,
limits on flavor-changing couplings are determined, many of which supersede
prior limits from rare decay processes.


title: Recent LEP 2 Results from OPAL

abstract:
  In 1996, after another set of upgrades, LEP began running for the first time
at center-of-mass energies above the W-pair production threshold. This new
energy regime is rich in physics and offers new tests of the Standard Model,
increased sensitivity for search physics, and precision W physics. We summarize
the recent results from OPAL using 9.9 pb^-1 of data collected at \sqrt s =
161.3 GeV from June to August 1996.


title: Search for charginos, neutralinos, and gravitinos at LEP

abstract:
  The hep-ex data base was decided not to be an appropriate place to make
DELPHI notes public. Sorry for the inconvenience.


title: Bose-Einstein Correlations in Deep Inelastic ep Scattering at HERA

abstract:
  Two-particle correlations in invariant mass are studied separately for
like-sign and unlike-sign charged particles produced in deep inelastic
positron-proton scattering in a new kinematical domain. The data were taken
with the H1 detector at the HERA storage ring in 1994, in which 27.5 GeV
positrons collided with 820 GeV protons at a centre of mass energy sqrt{s}=300
GeV. The observed enhancement of the like-sign correlations at low invariant
masses is related to the dimensions of the hadronic source. The data are
compared to different QCD models where the hadronization is performed with the
string-fragmentation model. Results are presented for the first time separately
for diffractive and non-diffractive scattering, in domains of four-momentum
transfer, Bjorken-x, and hadronic center of mass energy, and in intervals of
charged particle multiplicity. The observed source radii do not differ strongly
from those measured in lower energy lepton-nucleon inelastic scattering, and
e^+e^- annihilation.


title: A Future Charm Facility

abstract:
  The "BTeV/C0" experiment at Fermilab could reconstruct >10^9 charm decays,
four orders of magnitude beyond the largest extant sample. The experiment is
likely to run during Tevatron Run II (ca. 2000--2005). In addition to
"programmatic" charm physics such as spectroscopy, lifetimes, and QCD tests, it
will have significant new-physics reach in the areas of CP violation,
flavor-changing neutral-current and lepton-number-violating decays, and
$D^0\bar{D^0}$ mixing, and could observe direct CP violation in
Cabibbo-suppressed D decays if it occurs at the level predicted by the Standard
Model.


title: Pattern Recognition in High Multiplicity Events

abstract:
  In very high energy collisions, many particles are produced and distributed
in the available phase space volume in various ways. With advent of new
accelerator facilities (especially, for nucleus-nucleus collisions), the
problem of pattern recognition in high multiplicity events becomes very actual
in order to classify such events and to separate those of them with some
special features (e.g. ring-like events, jets and other regular patterns). This
paper presents the first attempt to use wavelet technique for pattern
recognition in nucleus-nucleus collisions. After describing the method in
general, we demonstrate its power by applying it to a single event of Pb-Pb
collision at 158A GeV with 1072 charged particles produced and discuss results
obtained for some other events. Further extension of the method is proposed.


title: Towards a Precise Parton Luminosity Determination at the CERN LHC

abstract:
  A new approach to determine the LHC luminosity is investigated. Instead of
employing the proton-proton luminosity measurement, we suggest to measure
directly the parton-parton luminosity. It is shown that the electron and muon
pseudorapidity distributions, originating from the decay of W+, W- and Z0
bosons produced at 14 TeV pp collisions (LHC), constrain the x distributions of
sea and valence quarks and antiquarks in the range from about 3 x 10**-4 to
about 10**-1 at a Q**2 of about 10**4 GeV**2. Furthermore, it is demonstrated
that, once the quark and antiquark structure functions are constrained from the
W+,W- and Z0 production dynamics, other quark-antiquark related scattering
processes at the LHC like q-qbar --> W+W- can be predicted accurately. Thus,
the lepton pseudorapidity distributions provide the key to a precise parton
luminosity monitor at the LHC, with accuracies of about +-1% compared to the so
far considered goal of +-5%.


title:
First Observation of Inclusive $B$ Decays to the Charmed Strange Baryons
  $\Xi_{c}^{0}$ and $\Xi_{c}^{+}$

abstract:
  Using data collected in the region of the Upsilon(4S) resonance with the CLEO
II detector operating at the Cornell Electron Storage Ring CESR, we present the
first observation of B mesons decaying into the charmed strange baryons Xi_c0
and Xi_c+. We find 79 +/- 27 Xi_c0 and 125 +/- 28 Xi_c+ candidates from B
decays, leading to product branching fractions of BR(Bbar -> Xi_c0 X)BR(Xi_c0
-> Xi- pi+) = (0.144 +/- 0.048 +/- 0.021) x 10^-3 and BR(Bbar -> Xi_c+
X)BR(Xi_c+ -> Xi- pi+ pi+) = (0.453 +/- 0.096 +0.085-0.065) x 10^-3.


title: Observation of the Decay $D_{s}^{+}\to \omega\pi^{+}$

abstract:
  Using e+e- annihilation data collected by the CLEO~II detector at CESR, we
have observed the decay Ds+ to omega pi+. This final state may be produced
through the annihilation decay of the Ds+, or through final state interactions.
We find a branching ratio of [Gamma(Ds+ to omega pi+)/Gamma(Ds+ to eta
pi+)]=0.16+-0.04+-0.03, where the first error is statistical and the second is
systematic.


title:
High Energy Muon Momentum Estimation from Multiple Coulomb Scattering in
  Dense Detectors

abstract:
  A method is described for estimating muon track momentum from the
distribution of hits along tracks in dense calorimeters due to multiple Coulomb
scattering (MCS). The method requires only well-aligned conventional drift
chambers or similar tracking devices and can be implemented with or without a
magnetic field present. Neutrino experiments can use this technique to increase
acceptance for large angle charged-current scattering events. Resolutions in a
typical detector geometry vary from ~10% at p=20 GeV/c to ~50% for p=500 GeV/c,
if the number of hits on the track is sufficient.


title: Totem: a case study in HEP

abstract:
  It is being proved that the neurochip \Totem{} is a viable solution for high
quality and real time computational tasks in HEP, including event
classification, triggering and signal processing. The architecture of the chip
is based on a "derivative free" algorithm called Reactive Tabu Search (RTS),
highly performing even for low precision weights. ISA, VME or PCI boards
integrate the chip as a coprocessor in a host computer. This paper presents: 1)
the state of the art and the next evolution of the design of \Totem{}; 2) its
ability in the Higgs search at LHC as an example.


title:
Determination of the Michel Parameters and the tau Neutrino Helicity in
  tau Decay

abstract:
  Using the CLEO II detector at the $e^+e^-$ storage ring CESR, we have
determined the Michel parameters $\rho$, $\xi$, and $\delta$ in $\tau^\mp \to
l^\mp\nu\bar{\nu}$ decay as well as the tau neutrino helicity parameter
$h_{\nu_\tau}$ in $\tau^\mp \to \pi^\mp\pi^0\nu$ decay. From a data sample of
$3.02\times 10^6$ tau pairs produced at $\sqrt{s}=10.6 GeV$, using events of
the topology $e^+e^- \to \tau^+\tau^- \to (l^\pm\nu\bar{\nu})
(\pi^\mp\pi^0\nu)$ and $e^+e^- \to \tau^+\tau^- \to (\pi^\pm\pi^0\bar{\nu})
(\pi^\mp\pi^0\nu)$, and the determined sign of $h_{\nu_\tau}$, the combined
result of the three samples is: $\rho = 0.747\pm 0.010\pm 0.006$, $\xi =
1.007\pm 0.040\pm 0.015$, $\xi\delta = 0.745\pm 0.026\pm 0.009$, and
$h_{\nu_\tau} = -0.995\pm 0.010\pm 0.003$. The results are in agreement with
the Standard Model V-A interaction.


title:
Limits on WWZ and WW\gamma couplings from p\bar{p}\to e\nu jj X events
  at \sqrt{s} = 1.8 TeV

abstract:
  We present limits on anomalous WWZ and WW-gamma couplings from a search for
WW and WZ production in p-bar p collisions at sqrt(s)=1.8 TeV. We use p-bar p
-> e-nu jjX events recorded with the D0 detector at the Fermilab Tevatron
Collider during the 1992-1995 run. The data sample corresponds to an integrated
luminosity of 96.0+-5.1 pb^(-1). Assuming identical WWZ and WW-gamma coupling
parameters, the 95% CL limits on the CP-conserving couplings are
-0.33<lambda<0.36 (Delta-kappa=0) and -0.43<Delta-kappa<0.59 (lambda=0), for a
form factor scale Lambda = 2.0 TeV. Limits based on other assumptions are also
presented.


title:
Evidence for Exotic Meson Production in the Reaction $ \pi^{-} p \to
  \eta \pi^{-} p$ at 18 GeV/c

abstract:
  The $\eta \pi^{-}$ system has been studied in the reaction $\pi^{-} p \to
\eta \pi^{-} p$ at 18 GeV/c. A large asymmetry in the angular distribution is
observed indicating interference between L-even and L-odd partial waves. The
$a_{2}(1320)$ is observed in the $J^{PC}$ = $2^{++}$ wave, as is a broad
enhancement between 1.2 and 1.6 GeV/c^{2} in the $J^{PC} = 1^{-+}$ wave. The
observed phase difference between these waves shows that there is phase motion
in addition to that due to $a_{2}(1320)$ decay. The data can be fitted by
interference between the $a_{2}(1320)$ and an exotic $1^{-+}$ resonance with $M
= (1370 \pm 16 {+50}\atop{-30}$) MeV/c^2 and $\Gamma =(385 \pm 40
{+65}\atop{-105}$) MeV/c^2.


title: Precision Determination of the Neutron Spin Structure Function g1n

abstract:
  We report on a precision measurement of the neutron spin structure function
$g^n_1$ using deep inelastic scattering of polarized electrons by polarized
^3He. For the kinematic range 0.014<x<0.7 and 1 (GeV/c)^2< Q^2< 17 (GeV/c)^2,
we obtain $\int^{0.7}_{0.014} g^n_1(x)dx = -0.036 \pm 0.004 (stat) \pm 0.005
(syst)$ at an average $Q^2=5 (GeV/c)^2$. We find relatively large negative
values for $g^n_1$ at low $x$. The results call into question the usual Regge
theory method for extrapolating to x=0 to find the full neutron integral
$\int^1_0 g^n_1(x)dx$, needed for testing quark-parton model and QCD sum rules.


title: Precise Tests of QCD in e+e- Annihilation

abstract:
  A pedagogical review is given of precise tests of QCD in electron-positron
annihilation. Emphasis is placed on measurements that have served to establish
QCD as the correct theory of strong interactions, as well as measurements of
the coupling parameter alpha-s. An outlook is given for future important tests
at a high energy e+e- collider.


title: Proton Dissociative Rho and Elastic Phi Electroproduction at HERA

abstract:
  The electroproduction of rho mesons with proton diffractive dissociation for
Q^2 > 7 GeV^2 and the elastic electroproduction of Phi mesons for Q^2 > 6 Gev^2
are studied in e^+ p collisions at HERA with the H1 detector, for an integrated
luminosity of 2.8 pb-1. The dependence of the cross sections on P_t^2 and Q^2
is measured, and the vector meson polarisation obtained. The cross section
ratio between proton dissociative and elastic production of rho mesons is
measured and discussed in the framework of the factorisation hypothesis of
diffractive vertices. The ratio of the elastic cross section for Phi and rho
meson production is investigated as a function of Q^2.


title:
Search for the Trilepton Signature from the Associated Production of
  SUSY Chi_1^(+-) Chi_2^0 Gauginos

abstract:
  We report on a search for the trilepton signature from the associated
production of supersymmetric gaugino pairs, Chi_1^(+-) Chi_2^0, within the
context of minimal supersymmetric models that conserve R-parity. This search
uses 95 pb^-1 of data taken with the \D0 detector at Fermilab's Tevatron
collider at \sqrt{s} = 1.8 TeV. No evidence of a trilepton signature has been
found, and a limit on the production cross section times branching fraction to
trileptons as a function of Chi_1^(+-) mass is given.


title: Measurements of the QCD Colour Factors at LEP

abstract:
  A summary of the measurements of the QCD colour factors at LEP is presented.
Such measurements provide a test of the gauge group structure underlying the
theory of strong interactions. A variety of methods have been applied by the
various experiments, and perfect consistency with the expectation of QCD with
SU(3) as gauge group is found.


title: Measurement of the Neutron Spin Structure Function g2n and Asymmetry A2n

abstract:
  We have measured the neutron structure function g$_{2}^{n}$ and the virtual
photon-nucleon asymmetry A$_{2}^{n}$ over the kinematic range $0.014\leq x \leq
0.7$ and $1.0 \leq Q^{2} \leq 17.0$ by scattering 48.3 GeV longitudinally
polarized electrons from polarized $^{3}$He. Results for A$_{2}^{n}$ are
significantly smaller than the $\sqrt{R}$ positivity limit over most of the
measured range and data for g$_2^{n}$ are generally consistent with the twist-2
Wandzura-Wilczek prediction. Using our measured g$_{2}^{n}$ we obtain results
for the twist-3 reduced matrix element $d_{2}^{n}$, and the integral
$\int$g$_{2}^{n}(x)dx$ in the range $0.014\leq x \leq 1.0$. Data from this
experiment are combined with existing data for g$_{2}^{n}$ to obtain an average
for $d_{2}^{n}$ and the integral $\int$g$_{2}^{n}(x)dx$.


title:
Photoproduction of K^0 and Lambda at HERA and a Comparison with Deep
  Inelastic Scattering

abstract:
  Inclusive $K^0$ and $\Lambda$ photoproduction has been investigated at HERA
with the H1 detector at an average photon-proton center of mass energy of 200
GeV in the transverse momentum range 0.5 <p_t <5 GeV. The production rates as a
function of $p_t$ and center of mass rapidity are compared to those obtained in
deep inelastic scattering at $\av{Q^2}=23 GeV^2$. A similar comparison is made
of the rapidity spectra of charged particles. The rate of strangeness
photoproduction is compared with $p\bar p$ measurements. The observations are
also compared with next-to-leading order QCD calculations and the predictions
of a Monte Carlo model.


title:
Measurement of the $\bar{B}\to D\ell\bar{\nu}$ Partila Width and Form
  Factor Parameters

abstract:
  We have studied the decay $\bar{B} \to D\ell\bar{\nu}$, where $\ell=e or
\mu$. From a fit to the differential decay rate $d\Gamma/dw$ we measure the
rate normalization ${\cal F}_D(1)|V_{cb}|$ and form factor slope
$\hat{\rho}^2_D$, and, using measured values of $\tau_B$, find $\Gamma(\bar{B}
\to D\ell\bar{\nu}) = (12.0 \pm 0.9 \pm 2.1) ns^{-1}$. The resulting branching
fractions are ${\cal B}(\bar{B}^0 \to D^+\ell^-\bar{\nu})=(1.87 \pm 0.15 \pm
0.32)%$ and ${\cal B}(B^- \to D^0\ell^-\bar{\nu})=(1.94 \pm 0.15 \pm 0.34)%$.
The form factor parameters are in agreement with those measured in $\bar{B} \to
D^*\ell\bar{\nu}$ decays, as predicted by heavy quark effective theory.


title: Role of Neural Networks in the Search of the Higgs Boson at LHC

abstract:
  We show that neural network classifiers can be helpful to discriminate Higgs
production from background at LHC in the Higgs mass range M= 200 GeV. We employ
a common feed-forward neural network trained by the backpropagation algorithm
for off-line analysis and the neural chip Totem, trained by the Reactive Tabu
Search algorithm, which could be used for on-line analysis.


title: Top Quark Production and Decay at the Tevatron

abstract:
  Recent measurements of the top quark production cross section and decay
properties by the CDF and D0 experiments are described. The cross section has
been measured in dilepton, lepton plus jets, and all-hadronic final states, and
a measurement of $BR(t \to Wb)/BR(t \to Wq)$, where $q$ is any quark, has been
performed. The results, though statistics-limited, are consistent with each
other and with theoretical predictions.


title: Measurement of Event Shape Variables in Deep Inelastic e^+ Scattering

abstract:
  Deep inelastic e^+ scattering data, taken with the H1 detector at HERA, are
used to study the event shape variables thrust, jet broadening and jet mass in
the current hemisphere of the Breit frame over a large range of momentum
transfers Q between 7 GeV and 100 GeV. The data are compared with results from
e^+e^- experiments. Using second order QCD calculations and an approach to
relate hadronisation effects to power corrections an analysis of the Q
dependences of the means of the event shape parameters is presented, from which
both the power corrections and the strong coupling constant are determined
without any assumption on fragmentation models. The power corrections of all
event shape variables investigated follow a 1/Q behaviour and can be described
by a common parameter alpha_0.


title:
Search for Single Leptoquark Production in Electron-Photon Scattering at
  161 and 172 GeV

abstract:
  A search for a first generation scalar leptoquark (LQ) has been performed
using the data collected by the OPAL detector in 1996 at e+e- centre-of-mass
energies sqrt{s} of 161 and 172 GeV. It is assumed that a single leptoquark can
be produced in the process eq->LQ, where the initial state quark originates
from a hadronic fluctuation of a quasi-real photon which has been radiated by
one of the LEP beams. Lower limits at the 95 % confidence level on the mass of
a first generation scalar leptoquark of 131 GeV for beta=0.5 and beta=1,
coupling values lambda larger than sqrt{4*pi*alpha_em) and leptoquark charges
-1/3 or -5/3 are obtained.


title:
On the Feasibility of Low-Background Ge-NaI Spectrometer for Neutrino
  Magnetic Moment Measurement

abstract:
  We analyze the possibility of using a low-background Ge-NaI spectrometer in a
reactor experiment for a search for neutrino magnetic moment down to $3 \times
10^{-11}$ of the electron magneton. The properties of the so-far existing Ge
low-background spectrometers are discussed and additional sources of background
in a reactor experiment at a small depth are estimated. These estimates place
specific requirements on the design of the spectrometer. The results of
preliminary background measurements at a small depth of 5 m.w.e. with a
dedicated spectrometer built in ITEP are reported.


title: A New Upper Limit on the Decay $\eta\to e^{+}e^{-}$

abstract:
  We have searched for the rare decay of the eta meson $\eta \to e^{+}e^{-}$
using the CLEO II detector. The $\eta$'s were produced in $e^{+}e^{-}$
collisions with 10 GeV center-of-mass energy at the Cornell Electron Storage
Ring (CESR). We find with 90% confidence the upper limit on the branching
fraction $B(\eta \to e^{+}e^{-}) < 7.7\times 10^{-5}$. The application of
conventional elementary particle theory to this decay predicts a branching
fraction of about $10^{-9}$.


title:
Search for sleptons in e+e- collisions at centre-of-mass energies of 161
  GeV and 172 GeV

abstract:
  The data recorded by the ALEPH experiment at LEP at centre-of-mass energies
of 161 GeV and 172 GeV were analysed to search for sleptons, the supersymmetric
partners of leptons. No evidence for the production of these particles was
found. The number of candidates observed is consistent with the background
expected from four-fermion processes and gammagamma-interactions. Improved mass
limits at 95% C.L. are reported.


title:
Dijet Production in Photon-Photon Collisions at sqrt(s)_ee=161 and 172
  GeV

abstract:
  Dijet production is studied in collisions of quasi-real photons radiated by
the LEP beams at e+e- centre-of-mass energies sqrt(s)_ee=161 and 172 GeV. Jets
are reconstructed using a cone jet finding algorithm in the range |eta(jet)|<2
and E_T(jet)>3 GeV. The angular distributions of direct and double-resolved
processes and the inclusive two-jet cross-section are measured. They are
compared to next-to-leading order perturbative QCD calculations and the
prediction of the leading order Monte Carlo generators PYTHIA and PHOJET.


title: Experimental study of high energy atmospheric neutrinos in Kamiokande

abstract: The paper has been withdrawn.


title: D* Production in Deep Inelastic Scattering at HERA

abstract:
  This paper presents measurements of D^{*\pm} production in deep inelastic
scattering from collisions between 27.5 GeV positrons and 820 GeV protons. The
data have been taken with the ZEUS detector at HERA. The decay channel
$D^{*+}\to (D^0 \to K^- \pi^+) \pi^+ $ (+ c.c.) has been used in the study. The
$e^+p$ cross section for inclusive D^{*\pm} production with $5<Q^2<100 GeV^2$
and $y<0.7$ is 5.3 \pms 1.0 \pms 0.8 nb in the kinematic region
{$1.3<p_T(D^{*\pm})<9.0$ GeV and $| \eta(D^{*\pm}) |<1.5$}. Differential cross
sections as functions of p_T(D^{*\pm}), $\eta(D^{*\pm}), W$ and $Q^2$ are
compared with next-to-leading order QCD calculations based on the photon-gluon
fusion production mechanism. After an extrapolation of the cross section to the
full kinematic region in p_T(D^{*\pm}) and $\eta$(D^{*\pm}), the charm
contribution $F_2^{c\bar{c}}(x,Q^2)$ to the proton structure function is
determined for Bjorken $x$ between 2 $\cdot$ 10$^{-4}$ and 5 $\cdot$ 10$^{-3}$.


title: B Decays to Two Charmless Pseudoscalar Mesons at CLEO

abstract:
  Using 3.3 Million $B\bar B$ pairs accumulated with the CLEO detector CLEO has
measured ${\cal B}(B^0\to K^+\pi^-) = (1.5^{+ 0.5}_{-0.4}\pm 0.1\pm 0.1)\times
10^{-5}$, ${\cal B}(B^+\to K^0\pi^+) = (2.3^{+1.1}_{-1.0}\pm 0.2\pm 0.2)\times
10^{-5}$, and ${\cal B}(B^+\to \eta^{'}K^+) = (7.8^{+ 2.7}_{-2.2}\pm 1.0)\times
10^{-5}$. These constitute the first observations of exclusive $B$\ decays to
charmless hadronic final states. Furthermore, a measurement of ${\cal B}(B^+\to
h^+\pi^0) = (1.6^{+ 0.6 +0.3}_{-0.5 -0.2}\pm 0.1)\times 10^{-5}$, as well as
upper limits on various other $B$ decays to two charmless pseudoscalar mesons
are presented. In particular, an upper limit of ${\cal B}(B^0\to \pi^+\pi^-) <
1.5\times 10^{-5}$ @ 90%C.L. is placed. All of these results are still
preliminary, and averaging over charge conjugate modes is always implied.


title: Top quark mass measurements from the Tevatron

abstract:
  We review the measurements of the top quark mass by the CDF and D-Zero
collaborations using Run I data in excess of 100 inverse picobarns. The D-Zero
collaboration has recently updated its measurement of the top quark mass in the
lepton + jets channel. The world average of the top quark mass from the CDF and
D-Zero measurements in the lepton + jets channel now stands at 175.6 +/- 5.5
GeV/c**2.


title:
Color Coherent Radiation in Multijet Events from ppbar Collisions at
  sqrt(s) = 1.8 TeV

abstract:
  We report on a study of color coherence effects in ppbar collisions at a
center of mass energy sqrt(s)=1.8 TeV. The data were collected with the D0
detector during the 1992-1993 run of the Fermilab Tevatron Collider. We observe
the presence of initial-to-final state color interference with the spatial
correlations between soft and hard jets in multijet events in the central and
in forward pseudorapidity regions. The results are compared to Monte Carlo
simulations with different color coherence implementations and to the
predictions of O(alpha_s^3) QCD calculations.


title:
Search for pair-production of long-lived heavy charged particles in e+e-
  annihilation

abstract:
  A search for pair-production of long-lived, heavy, singly-charged particles
has been performed with data collected by the ALEPH detector at a
centre-of-mass energy of 172 GeV. Data at \sqrt{s} = 161, 136, and 130 GeV are
also included to improve the sensitivity to lower masses. No candidate is found
in the data. A model-independent 95% confidence level upper limit on the
production cross section at 172 GeV of 0.2-0.4pb is derived for masses between
45 and 86 GeV/c^2. This cross section limit implies, assuming the MSSM, a lower
limit of 67 (69) GeV/c^2 on the mass of right- (left-) handed long-lived scalar
taus or scalar muons and of 86 GeV/c^2 on the mass of long-lived charginos.


title: Measurement of the Top Quark Mass Using Dilepton Events

abstract:
  The D0 collaboration has performed a measurement of the top quark mass based
on six candidate events for the process t tbar -> b W+ bbar W-, where the W
bosons decay to e nu or mu nu. This sample was collected during an exposure of
the D0 detector to an integrated luminosity of 125 pb^-1 of sqrt(s)=1.8 TeV
p-pbar collisions. We obtain mt = 168.4 +- 12.3 (stat) +- 3.7 (sys) GeV/c^2,
consistent with the measurement obtained using single-lepton events.
Combination of the single-lepton and dilepton results yields mt = 172.0 +- 7.5
GeV/c^2.


title: Tevatron Results on Gauge Boson Couplings

abstract:
  Direct measurements of the trilinear gauge boson couplings by the CDF and D0
collaborations at Fermilab are reviewed. Limits on the anomalous couplings were
obtained at a 95 % CL from four diboson production processes: W-gamma
production with the subsequent W boson decay to e-nu or mu-nu, WW production
with both the W boson decaying to e-nu or mu-nu, WW/WZ production with one of
the gauge bosons decaying leptonically and the other gauge boson decaying to
two jets, and Z-gamma production with the subsequent Z boson decay to e-e,
mu-mu, or nu-nu. Limits were also obtained by a combined fit to W-gamma, WW to
dileptons and WW/WZ semileptonic data samples.


title: Confidence level estimation and analysis optimization

abstract:
  This note proposes a method, which can be applied to searches and more in
general to any cross section measurement, to maximize the analysis sensitivity.


title: B Physics at SLD

abstract:
  We review recent $B$ physics results obtained in polarized $e^+ e^-$
interactions at the SLC by the SLD experiment. The excellent 3-D vertexing
capabilities of SLD are exploited to extract precise $\bu$ and $\bd$ lifetimes,
as well as measurements of the time evolution of $B^0_d - \bar{B^0_d}$ mixing.


title: Recent Results from the study of QCD and Jets at HERA

abstract:
  The HERA experiments H1 and ZEUS have recently presented a number of
interesting results from studies of the hadronic final state produced in $ep$
collisions. These studies have focussed on deep inelastic scattering events and
on the photoproduction of jets, and also on the comparison of the final states
produced in these two regimes. Some of these results are reviewed here.


title: A New Measurement of $B\to D^{*}\pi$ Branching Fractions

abstract:
  The decays Upsilon(4S) -> BB, followed by B -> D* pi and D* -> D pi, permit
reconstruction of all kinematic quantities that describe the sequence without
reconstruction of the D, with reasonably low backgrounds. Using an integrated
e+e- luminosity of 3.1 fb^{-1} accumulated at the Upsilon(4S) by the CLEO-II
detector, we report measurements of BR(B0 -> D*+ pi-) = (2.81 +/- 0.11 +/- 0.21
+/- 0.05) x 10^{-3} and BR(B- -> D*0 pi-) = (4.34 +/- 0.33 +/- 0.34 +/- 0.18) x
10^{-3}.


title:
First Observation of $\tau\to 3\pi\eta\nu_{\tau}$ and $\tau\to
  f_{1}\pi\nu_{\tau}$ Decays

abstract:
  We have observed new channels for $\tau$ decays with an $\eta$ in the final
state. We study 3-prong tau decays, using the $\eta\to\gamma\gamma$ and
$\eta\to 3\piz$ decay modes and 1-prong decays with two $\piz$'s using the
$\eta\to\gamma\gamma$ channel. The measured branching fractions are
$\B(\tau^{-}\to \pi^{-}\pi^{-}\pi^{+}\eta\nu_{\tau})
  =(3.4^{+0.6}_{-0.5}\pm0.6)\times10^{-4}$ and $\B(\tau^{-}\to
\pi^{-}2\piz\eta\nu_{\tau}
  =(1.4\pm0.6\pm0.3)\times10^{-4}$. We observe clear evidence for
$f_1\to\eta\pi\pi$ substructure and measure $\B(\tau^{-}\to
f_1\pi^{-}\nu_{\tau})=(5.8^{+1.4}_{-1.3}\pm1.8)\times10^{-4}$. We have also
searched for $\eta'(958)$ production and obtain 90% CL upper limits
$\B(\tau^{-}\to \pi^{-}\eta'\nu_\tau)<7.4\times10^{-5}$ and $\B(\tau^{-}\to
\pi^{-}\piz\eta'\nu_\tau)<8.0\times10^{-5}$.


title: Asymmetries from Semi-inclusive Polarized Deep Inelastic Scattering

abstract:
  The analysis of semi-inclusive data from deep inelastic scattering of
polarized muons off polarized protons and deuterons by the SMC is presented.
The resulting charged hadron asymmetries are used to determine polarized
valence and sea quark distributions and their contributions to the nucleon
spin. In addition, a new approach to derive inclusive asymmetries is discussed.


title: High Energy Photoproduction

abstract:
  The study of photoproduction reactions has gained a unique opportunity with
the HERA data. The high center of mass energy allows to carry out quantitative
tests of QCD, to explore the substructure of both the photon and the proton and
to shed new light on soft and diffractive processes. In this report we review
the HERA results, comparing them with the reach of fixed target photoproduction
experiments and complementary measurements from $e^+ e^-$ and hadron colliders.


title:
KARMEN: Present Neutrino-Oscillation Limits and Perspectives after the
  Upgrade

abstract:
  The neutrino experiment KARMEN is situated at the beam stop neutrino source
ISIS. It provides nu_mu's, nu_e's and nu_mu_bar's in equal intensities from the
pi+ mu+ decay at rest. The oscillation channels nu_mu->nu_e and
nu_mu_bar->nu_e_bar are investigated with a 56t liquid scintillation
calorimeter at a mean distance of 17.6m from the nu source. No evidence for
oscillations could be found with KARMEN, resulting in 90% CL exclusion limits
of sin(2th) < 8.5 10^-3 (nu_mu_bar->nu_e_bar) and sin(2th) < 4.0 10^-2
(nu_mu->nu_e) for Delta m^2 > 100eV^2. In 1996, the KARMEN neutrino experiment
has been upgraded by an additional veto system. Vetoing of cosmic muons passing
the 7000t massive iron shielding of the detector suppresses energetic neutrons
from deep inelastic scattering of muons as well as from mu-capture in iron. Up
to 1996, these neutrons penetrating into the detector represented the main
background for the nu_mu_bar->nu_e_bar oscillation search. With an expected
reduction of the background rate by a factor of 40 the experimental sensitivity
for nu_mu_bar->nu_e_bar will be significantly enhanced towards sin(2th) = 10^-3
for large Delta m^2.


title: Recent Results from the Search for New Phenomena at D0

abstract:
  We present results from several new searches for physics beyond the Standard
Model. We describe a search based on the scalar sum of the transverse energy of
the event, a global quantity nearly independent of the event topology. We
summarize our searches for first generation leptoquarks into all three decay
channels, eq eq, eq nu q, and nu q nu q, and note that this is the first time
that the triumvirate of decay channels has been searched. We do not find any
evidence for production of first generation leptoquarks and set a lower limit
on the mass of the leptoquark of 175 GeV/c^2, assuming the decay is exclusively
into eq eq. We also present results from the first search for a third
generation leptoquark with charge = +/- 1/3. Again, we find no evidence for its
existence for a mass less than 80 GeV/c^2. Finally, we discuss one of our
searches for supersymmetry, specifically the pair-production of selectrons,
sneutrinos, and chi_2^0 where the decay yields final states with two photons
plus missing transverse energy. We set limits on the production cross section
ranging from 1 pb to 400 fb, depending on the mass. This analysis also sets a
model-independent upper limit on the cross section times branching ratio to two
photons + missing transverse energy + X of 185 fb at the 95% CL for transverse
energy of the photons > 12 GeV with eta < 1.1 and missing transverse energy >
25 GeV.


title: The doubly Cabibbo-suppressed decay $D^+\to K^+ \pi^- \pi^+$

abstract:
  We report the observation of the doubly Cabibbo-suppressed decay $D^+\to K^+
\pi^- \pi^+$ in data from Fermilab charm hadroproduction experiment E791. With
a signal of 59 \pm 13 events we measured the ratio of the branching fraction
for this mode to that of the Cabibbo-favored decay $D^+\to K^- \pi^+ \pi^+$ to
be $B(D^+ \to K^+ \pi^- \pi^+) / B(D^+ \to K^- \pi^+ \pi^+) = (7.7 \pm 1.7 \pm
0.8) \times 10^{-3}$. A Dalitz plot analysis was performed to search for
resonant structures.


title: Search for Leptoquarks at CDF

abstract:
  We present the result of direct leptoquark searches based on 110 pb-1 of
integrated luminosity collected by the Collider Detector at Fermilab during the
1992-93 and 1994-95 Tevatron runs at \sqrt{s}=1.8 TeV. We present upper limits
on the production cross sections as a function of the leptoquark mass. Using
the NLO calculation of the leptoquark-pair production cross sections we extract
lower-mass limits for first, second and third generation leptoquarks. We also
present the result of an indirect search for Pati-Salam leptoquarks via
exclusive e-mu decay modes of B^{0}_{s} and B^{0}_{d}.


title: Search for Leptoquarks at D0

abstract:
  We present in this paper the current status of searches for leptoquarks at
D0. These results include the use of next leading order theoretical predictions
for the cross section for pair production of leptoquarks at hadron colliders.
We also present a new optimized analysis for first generation leptoquarks with
significant increase in sensitivity relative to earlier searches using D0 data.
The mass limits derived from this first generation leptoquark search are
relevant to the recently reported high mass events at HERA.


title: D0 Results on W Boson Properties

abstract:
  Results from analyses of events with W and Z bosons are presented for the D0
Tevatron run 1B data samples. From the leptonic decays of the W and Z, the W
and Z production cross sections and the W width are determined. Events in which
the W decays into a tau and neutrino are used to determine the ratio of the
electroweak gauge coupling constants as a measure of lepton universality. Using
W and Z decays into electrons, the the W boson mass is measured.


title: Jet Photoproduction

abstract:
  The status of HERA data on jet photoproduction is reviewed, and some
suggestions and prospects for further work are given.


title: Tuning MC Models to Fit DIS e-gamma Scattering Events

abstract:
  Monte Carlo models of DIS e-gamma scattering must describe hard emissions as
well as the soft and collinear limits. Comparison with the observed
experimental hadronic energy flow has shown that various models underestimate
the high-p_T contribution, in particular at low-x. We have attempted to tune
the Herwig, Pythia and Ariadne models to improve the agreement with the data,
and to understand the physical implications of the changes required. Unless the
physics of these processes is understood it will not be possible to unfold the
photon structure functions F_2^\gamma from the e^+e^- data without large model
dependent systematic errors.


title: Energy Flows and Jet Production in Tagged e-gamma Events at LEP

abstract:
  It has already been shown that the energy flow distributions in tagged events
disagree with those predicted by QCD models, generating serious systematic
errors in the unfolding of the photon structure function $F_{2}^{\gamma}$. This
new analysis uses the jet structure in the hadronic final state to identify the
class of events which is in worst agreement with the models. A cone jet finder
is used to select events with 0,1 or 2 jets whose transverse energy is greater
than 3 GeV. Tagged electrons are detected in the OPAL forward detector at
angles between 60 and 120 milliradians. As well as the QCD-based Monte Carlo
models, HERWIG and PYTHIA, the simple F2GEN program is used to give a
comparison sample of events with purely pointlike photon-quark coupling.


title: Searching the Higgs with the Neurochip TOTEM

abstract:
  We show that neural network classifiers can be helpful in discriminating
Higgs production events from the huge background at LHC, assuming the case of a
mass value $M_H \sim 200$ GeV. We use the high performance neurochip TOTEM,
trained by the Reactive Tabu Search algorithm (RTS), which could be used for
on-line purposes. Two different sets of input variables are compared.


title:
Evolution of ep Fragmentation and Multiplicity Distributions in the
  Breit Frame

abstract:
  Low x deep-inelastic ep scattering data, taken in 1994 at the H1 detector at
HERA, are analysed in the Breit frame of reference. The evolution of the peak
and width of the current hemisphere fragmentation function is presented as a
function of Q and compared with e+e- results at equivalent centre of mass
energies. Differences between the average charged multiplicity and the
multiplicity of e+e- annihilations at low energies are analysed. Invariant
energy spectra are compared with MLLA predictions. Distributions of
multiplicity are presented as functions of Bjorken-x and Q^2, and KNO scaling
is discussed.


title: Recent Photoproduction Results From ZEUS

abstract:
  Recent results from ZEUS for inclusive jet cross sections, dijet cross
sections and dijet angular distributions are compared with NLO perturbative QCD
calculations. The observation of isolated high $P_T$ photons (prompt photons)
is also reported.


title: Review of Rare and Forbidden $\tau$ Decays

abstract:
  This is a review of rare and forbidden decays of the $\tau$ lepton. For the
rare decays, this includes new results on the chiral anomaly decay
$\taupietapio$, new upper limits on the second-class-current decay $\taupieta$,
and the observations of the Cabibbo-suppressed decay $\tauketa$ and the
internal conversion decay $\taueee$. For the forbidden decays, there are new
upper limits on the radiative decays $\tauegamma$ and $\taumugamma$. Some
forbidden decays which have not been previously searched for are also
suggested.


title: Meson Spectroscopy and the Search for Exotics

abstract:
  I will review the current status of exotic hadrons in the meson sector. There
is currently strong evidence that a scalar glueball mixed into the normal
scalar mesons has been found. There is also an interesting candidate for the
tensor glueball state. Finally, I will discuss hybrid mesons with explicitly
exotic quantum numbers.


title:
A Study of B Meson Oscillations Using Hadronic Z^0 Decays Containing
  Leptons

abstract:
  An event sample enriched in semileptonic decays of b hadrons is selected
using an inclusive lepton selection from approximately 3.0 million hadronic Z^0
decays collected with the OPAL detector. This sample is used to investigate B
meson oscillations by reconstructing a proper decay time for the parent of each
lepton, using a jet charge method to estimate the production flavour of this
parent, and using the lepton charge to tag the decay flavour. We measure the
mass difference between the two B^0_d mass eigenstates
  Delta(m_d) = 0.444 +/- 0.029 + 0.020 - 0.017 ps^-1.
  For the B^0_s system, we find Delta(m_s) > 3.1 ps^-1 at the 95% confidence
level. This limit varies only a little if alternative limit setting approaches
are adopted. Regions at higher Delta(m_s) are also excluded with some methods
for setting the limit.
  By studying the charge symmetry of the B^0_d mixing structure, we are able to
constrain possible CP and CPT violating effects. We measure the CP violation
parameter
  Re(epsilon_B) = -0.006 +/- 0.010 +/- 0.006
  and the indirect CPT violating parameter
  Im(delta_B) = -0.020 +/- 0.016 +/- 0.006.
  If we invoke CPT symmetry, then we obtain
  Re(epsilon_B) = 0.002 +/- 0.007 +/- 0.003.


title: An Updated Study of B Meson Oscillations using Dilepton Events

abstract:
  This paper reports a study of B meson oscillations using hadronic Z^0 decays
with two identified leptons, and updates a previous publication by including
data collected in 1994. Decay times are reconstructed for each of the
semileptonic B decays by forming vertices which include the lepton and by
estimating the B meson momentum. The mass difference, Delta(m_d), between the
two mass eigenstates in the B^0_d system is measured to be
  0.430 +/- 0.043 + 0.028 - 0.030 ps^-1, where the first error is statistical
and the second error is systematic. For the B^0_s system, a lower limit of
Delta(m_s) > 2.2 ps^-1 is obtained at 95% C.L.