Unnamed: 0 int64 0 41k | title stringlengths 4 274 | category stringlengths 5 18 | summary stringlengths 22 3.66k | theme stringclasses 8
values |
|---|---|---|---|---|
7,200 | An optimal method of moments to measure the charge asymmetry at the $Z^0$ | hep-ex | Parity violation at LEP or SLC can be measured through the charge asymmetry.
An optimal method of moments is developed here to measure this asymmetry, as
well as similar asymmetries. This method is equivalent to the likelihood fit.
It is simpler in use, as it gives analytical formulas for both the asymmetry
and its sta... | physics |
7,201 | Observation of Anisotropic Event Shapes and Transverse Flow in Au+Au Collisions at AGS Energy | hep-ex | Event shapes for Au + Au collisions at 11.4 GeV/c per nucleon were studied
over nearly the full solid angle with the E877 apparatus. The analysis was
performed by Fourier expansion of azimuthal distributions of the transverse
energy (E_T) measured in different pseudorapidity intervals. For semicentral
collisions a pron... | physics |
7,202 | Measurement of alpha-s from energy-energy correlations at the Z0 resonance | hep-ex | We have determined the strong coupling alpha-s from a comprehensive study of
energy-energy correlations (EEC) and their asymmetry (AEEC) in hadronic decays
of Z0 bosons collected by the SLD experiment at SLAC. The data were compared
with all four available predictions of QCD calculated up to O(alpha-s**2) in
perturbati... | physics |
7,203 | A Precise Measurement of the Weak Mixing Angle in Neutrino-Nucleon Scattering | hep-ex | We report a precise measurement of the weak mixing angle from the ratio of
neutral current to charged current inclusive cross-sections in deep-inelastic
neutrino-nucleon scattering. The data were gathered at the CCFR neutrino
detector in the Fermilab quadrupole-triplet neutrino beam, with neutrino
energies up to 600 Ge... | physics |
7,204 | Precise Determination of the Weak Mixing Angle from a measurement of ALR in e+e- -> Z0 | hep-ex | In the 1993 SLC/SLD run, the SLD recorded 50,000 $\z0$ events produced by the
collision of longitudinally polarized electrons on unpolarized positrons at a
center-of-mass energy of 91.26 GeV. The luminosity-weighted average
polarization of the SLC electron beam was (63.0$\pm$1.1)\%. We measure the
left-right cross-sect... | physics |
7,205 | LEP asymmetries and fits of the Standard Model | hep-ex | The lepton and quark asymmetries measured at LEP are presented. The results
of the Standard Model fits to the electoweak data presented at this conference
are given. The top mass obtained from the fit to the LEP data is
$172^{+13+18}_{-14-20}$ GeV; it is $177^{+11+18}_{-11-19}$ when also the
collider, $\nu$ and $A_{LR}... | physics |
7,206 | Average Multiplicities in Gluon and Quark Jets in Higher-Order Perturbative QCD | hep-ex | The ratio of average multiplicities in gluon and quark jets is shown to
become noticeably smaller in higher-order QCD compared to its lowest order
value what improves agreement with experiment.
QCD anomalous dimension has been calculated. It has been used to get energy
dependence of mean multiplicities. | physics |
7,207 | A Neural Network for Locating the Primary Vertex in a Pixel Detector | hep-ex | Using simulated collider data for $p+p\rightarrow 2{\rm Jets}\ $ interactions
in a 2-barrel pixel detector, a neural network is trained to construct the
coordinate of the primary vertex to a high degree of accuracy. Three other
estimates of this coordinate are also considered and compared to that of the
neural network.... | physics |
7,208 | Semileptonic Branching Fraction of Charged and Neutral B Mesons | hep-ex | An examination of leptons in ${\Upsilon (4S)}$ events tagged by reconstructed
$B$ decays yields semileptonic branching fractions of $b_-=(10.1 \pm 1.8\pm
1.4)\%$ for charged and $b_0=(10.9 \pm 0.7\pm 1.1)\%$ for neutral $B$ mesons.
This is the first measurement for charged $B$. Assuming equality of the charged
and neut... | physics |
7,209 | Measurement of the B -> D^* l nu Branching Fractions and |Vcb| | hep-ex | We study the exclusive semileptonic B meson decays B- -> D*0 l- nu and B0 ->
D*+ l- nu using data collected with the CLEO II detector at CESR. We present
measurements of the branching fractions B(B0 -> D*+ l-nu) = 0.5/f00*
[4.49+/-0.32+/-0.39]% and B(B- -> D*0 l-nu) = 0.5/f+-*[5.13+/-0.54+/-0.64]%,
where f00 and f+- ar... | physics |
7,210 | Multiple Scattering Error Propagation in Particle Track Reconstruction | hep-ex | Particle track reconstruction capabilities of the silicon tracking detector
system have been studied. As the multiple Coulomb scattering (MCS) induces
unavoidable uncertainties on the coordinate measurement, the corresponding
error estimates and the associated correlations have been used to find the best
track fit para... | physics |
7,211 | Determination of the Strange Quark Content of the Nucleon from a Next-to-Leading-Order QCD Analysis of Neutrino Charm Production | hep-ex | We present the first next-to-leading-order QCD analysis of neutrino charm
production, using a sample of 6090 $\nu_\mu$- and $\bar\nu_\mu$-induced
opposite-sign dimuon events observed in the CCFR detector at the Fermilab
Tevatron. We find that the nucleon strange quark content is suppressed with
respect to the non-stran... | physics |
7,212 | CPT Tests in the Neutral Kaon System by FNAL E773 | hep-ex | The FNAL experiment E773 has measured the phases Phi_{+-} = (43.35 +- 0.70 +-
0.79) degree and Phi_{00}-Phi_{+-} = (0.67 +- 0.85 +- 1.1) degree of the CP
violating parameters eta_{+-} and eta_{00} in the decay of neutral kaons into
two charged or neutral pions. These preliminary results test CPT symmetry and
show no ev... | physics |
7,213 | Top Mass from Electroweak Measurements | hep-ex | The electroweak measurements made at LEP using 1989-1993 data are presented
in preliminary form. The agreement with the Standard Model is satisfactory, and
allows a combined fit to all available data for the masses of the top quark and
standard Higgs boson. The fit yields M_t = 177 +11 -11 +18 -19 GeV/c2, where
the sec... | physics |
7,214 | Spin Asymmetry in Muon--Proton Deep Inelastic Scattering on a Transversely-Polarized Target | hep-ex | We measured the spin asymmetry in the scattering of 100 GeV
longitudinally-polarized muons on transversely polarized protons. The asymmetry
was found to be compatible with zero in the kinematic range $0.006<x<0.6$,
$1<Q^2<30\,~\mbox{GeV}^2$. {}From this result we derive the upper limits for
the virtual photon--proton a... | physics |
7,215 | New Measurements of CP Violation Parameters as Tests of CPT in K Meson Decay | hep-ex | Using a technique which employs a pair of solid scintillator regenerators,
the E773 collaboration has measured several CP violation parameters in K meson
decay at Fermilab. We report new results for the phase of eta_+-, the K_L-K_S
mass difference, the K_S lifetime, and the phase difference
Arg(eta_00)-Arg(eta_+-) in K... | physics |
7,216 | New Results from CLEO-II on Hadronic Decays of the Tau Lepton | hep-ex | Results on semi-hadronic decays of the $\tau$ lepton are presented, from
studies of $e^+e^-$ annihilation data obtained at the Cornell Electron Storage
Ring with the CLEO-II detector. Branching fractions have been measured for
decays to two, three and four hadrons, namely $\tau^-\!\!\rightarrow\! \nu_\tau
h^-\pi^0$, $\... | physics |
7,217 | Measurement of the polarization of Lambda0 AntiLambda0, Sigma+ and Xi- produced in a Sigma- beam of 330 GeV/c | hep-ex | The polarization of Lambda0, AntiLambda0, Sigma+ and Xi- inclusively produced
in Sigma- induced interactions at 330 GeV has been measured in the experiment
WA89 at CERN. This is the first measurement of polarization of baryons produced
by a hyperon beam. No polarization of AntiLambda is observed, as was also the
case i... | physics |
7,218 | B+ and B0 Mean Lifetime Measurements | hep-ex | We review $B^+$ and $B^0$ mean lifetime measurements, including direct
measurements and determination of the lifetime ratio via measurements of the
ratio of branching ratios. We present world averages. | physics |
7,219 | Determination of the branching ratios $Γ(K_L \to 3 π^0) / Γ (K_L \to π^+ π^- π^0)$ and $Γ(K_L \to 3 π^0) / Γ(K_L \to πe ν)$ | hep-ex | Improved branching ratios were measured for the $K_L \to 3 \pi^0 $ decay in a
neutral beam at the CERN SPS with the NA31 detector: $\Gamma (K_L \to 3 \pi^0)
/ \Gamma (K_L \to \pi^+ \pi^- \pi^0) = 1.611 \pm 0.037$ and $\Gamma (K_L \to 3
\pi^0) / \Gamma (K_L \to \pi e \nu ) = 0.545 \pm 0.010$.
From the first number an ... | physics |
7,220 | Measurement of the branching fraction for $Υ(1S) \to τ^+ τ^-$ | hep-ex | We have studied the leptonic decay of the $\Upsilon (1S)$ resonance into tau
pairs using the CLEO II detector. A clean sample of tau pair events is
identified via events containing two charged particles where exactly one of the
particles is an identified electron. We find $B(\Upsilon(1S) \to \tau^+ \tau^-)
= (2.61~\pm~... | physics |
7,221 | Search for top in D-Zero using the electron + jets channel with soft muon tagging | hep-ex | We present preliminary results for the search for the top quark in D-Zero in
the electron + jets channel where one of the b quark jets is tagged by means of
a soft muon, using 13.5 pb-1 of data. Standard model decay modes for the top
quark are assumed. We present the resulting top cross section and error as a
function ... | physics |
7,222 | Search for the Top Quark: Results from the D-Zero Experiment | hep-ex | We review the search for the top quark conducted by the D-Zero collaboration
using data from the Fermilab pbar-p collider. Based upon a preliminary analysis
of an integrated luminosity of about 13.5 pb-1, we have searched for t-tbar
production and decay in the experimental channels involving a pair of dileptons
(electr... | physics |
7,223 | Search for top in lepton + jets in D-Zero using a topological tag | hep-ex | We have searched for production of t-tbar pairs in p-pbar interactions at 1.8
TeV center-of-mass energy at the FNAL Tevatron collider. The search assumes
standard model decay for top quark into W + b quark. We observe in e+jet and
mu+jet final states a small, not statistically significant, excess above the
background e... | physics |
7,224 | Search for First and Second Generation Leptoquarks at DØ | hep-ex | A search for first and second generation leptoquarks has been done with the
D\O \ detector at Fermilab's p\={p} collider with $\sqrt{s}=1.8$ TeV. 95\% C.L.
mass limits for first generation scalar leptoquarks have been recently
published. The number for the total integrated luminosity used in the first
generation leptoq... | physics |
7,225 | Search for Supersymmetric Wino and Zino States Using the D0 Detector | hep-ex | The status of a search for the pair production of the lightest chargino and
second lightest neutralino states of the minimal supersymmetric model is
presented. We have searched for four tri-lepton final states: eee, eemu, emumu,
and mumumu, all with missing transverse energy. | physics |
7,226 | Search for Supersymmetry and Leptoquark States at FNAL | hep-ex | Searches have been made for first generation scalar and vector leptoquarks by
the D0 collaboration and for second generation scalar leptoquarks by the CDF
collaboration. Lower leptoquark mass limits were set. A search for squarks and
gluinos, predicted by Supersymmetric models, was made by D0 in the three or
more jets ... | physics |
7,227 | New Shower Maximum Trigger for Electrons and Photons at CDF | hep-ex | For the 1994 Tevatron collider run, CDF has upgraded the electron and photon
trigger hardware to make use of shower position and size information from the
central shower maximum detector. For electrons, the upgrade has resulted in a
50\% reduction in backgrounds while retaining approximately 90\% of the signal.
The new... | physics |
7,228 | Measurement of Correlated $b$ Quark Cross Sections at CDF | hep-ex | Using data collected during the 1992-93 collider run at Fermilab, CDF has
made measurements of correlated $b$ quark cross section where one $b$ is
detected via a muon from semileptonic decay and the second $b$ is detected with
secondary vertex techniques. We report on measurements of the cross section as
a function of ... | physics |
7,229 | Search for slowly moving magnetic monopoles | hep-ex | We report a search for slowly moving magnetic monopoles in the cosmic
radiation with the first supermodule of the MACRO detector at Gran Sasso. The
absence of candidates established an upper limit on the monopole flux of
$5.6\times10^{-15}\mbox{cm}^{-2}\mbox{sr}^{-1}\mbox{s}^{-1}$ at 90\% confidence
level for the veloc... | physics |
7,230 | Measurement of Correlated b quark Cross Sections at CDF | hep-ex | Using data collected during the 1992-1993 collider run at Fermilab, CDF has
made measurements of correlated $b$ quark cross sections where one $b$ is
detected from the lepton from semileptonic decay and the second $b$ is detected
with secondary vertex techniques. We report on measurements of the cross
section as a func... | physics |
7,231 | A Study of Events with Large Total Transverse Energy Produced in Proton-Antiproton Collisions at sqrt{s} = 1.8 Tev | hep-ex | Properties of events originating from proton--antiproton interactions in
which the total transverse energy of the event exceeded 400 GeV are presented.
Based on a data sample of 5.45 pb-1, the topology of these hard scattering
events as well as preliminary results for the cross--section versus total
transverse energy a... | physics |
7,232 | Polarized Bhabha Scattering and a Precision Measurement of the Electron Neutral Current Couplings | hep-ex | We present the first measurement of the left-right asymmetry in Bhabha
scattering with a polarized electron beam. The effective electron vector and
axial vector couplings to the Z0 are extracted from a combined analysis of the
polarized Bhabha scattering data and the left-right asymmetry previously
published by this co... | physics |
7,233 | Search for Top with D0 Detector in Dilepton Channel | hep-ex | Preliminary results from a search for high mass ttbar quark pair production
in ppbar collisions at sqrt(s)=1.8TeV with the D0 detector in the ee+jets,
emu+jets, and mumu+jets decay channels are presented. No conclusive evidence
for top quark production for an integrated luminosity of 13.5+/-1.6pb-1 is
observed. | physics |
7,234 | VLPC Characterization for the Dzero Upgrade | hep-ex | We have studies the performance characteristics of approximately 4000 Visible
Light Photon Counters(VLPC) over a range of operating temperatures and biases.
We will describe the characterization procedure and present the measured gain,
noise and the relative quantum efficiency for the devices. We will also discuss
the ... | physics |
7,235 | Search for High Mass Top Quark Production in p anti-p Collisions at S**(1/2) = 1.8 TeV | hep-ex | We present new results on the search for the top quark in p anti-p collisions
at S**(1/2) = 1.8 TeV with an integrated luminosity of 13.5 +- 1.6 pb**(-1). We
have considered t anti-t production in the Standard Model using electron and
muon dilepton decay channels (t anti-t -> e mu + jets, e e + jets, and mu mu +
jets) ... | physics |
7,236 | A Measurement of the $D^{*\pm}$ Cross Section in Two-Photon Processes | hep-ex | We have measured the inclusive $D^{*\pm}$ production cross section in a
two-photon collision at the TRISTAN $e^+e^-$ collider. The mean $\sqrt{s}$ of
the collider was 57.16 GeV and the integrated luminosity was 150 $pb^{-1}$. The
differential cross section ($d\sigma(D^{*\pm})/dP_T$) was obtained in the $P_T$
range betw... | physics |
7,237 | Measurement of the $D^{*\pm}$ Cross Section using a Soft-Pion Analysis in Two-Photon Processes | hep-ex | The differential cross section of $d\sigma(e^+e^-\to e^+e^-D^{*\pm}X)/dP_T$
was measured using a soft-pion analysis of $D^{*\pm}\to \pi_s^\pm
D^0(\bar{D^0})$ at TRISTAN. The average $\sqrt{s}$ was 58.1 GeV and the
integrated luminosity used in this analysis was 198 pb$^{-1}$, respectively. | physics |
7,238 | $K^0(\bar{K^0})$ Production in Two-Photon Processes at TRISTAN | hep-ex | We have carried out an inclusive measurement of $K^0(\bar{K^0})$ production
in two-photon processes at TRISTAN. The mean $\sqrt{s}$ was 58 GeV and the
integrated luminosity was 199 pb$^{-1}$. High-statistics $K_s$ samples were
obtained under such conditions as no-, anti-electron, and remnant-jet tags. The
remnant-jet t... | physics |
7,239 | On the Kinematic Reconstruction of Deep Inelastic Scattering at HERA: the $Σ$ Method | hep-ex | We review and compare the reconstruction methods of the inclusive deep
inelastic scattering variables used at HERA. We introduce a new prescription,
the $\Sigma$ method, which allows to measure the structure function of the
proton $F_2(x,Q^2)$ in a large kinematic domain, and in particular in the low
x-low$Q^2$ region,... | physics |
7,240 | New Tagging Method of B Flavor of Neutral B Meson in CP Violation Measurement in Asymmetric B-Factory Experiment | hep-ex | In CP violation measurements in asymmetric B-factory experiments, a
determination of the B flavor of the neutral B mesons is necessary. A new
method to this purpose using only three vectors of charged particles has been
developed. This method (weighted charge method) does not require either lepton
identification or cha... | physics |
7,241 | Observation of Target Electron Momentum Effects in Single-Arm Møller Polarimetry | hep-ex | In 1992, L.G. Levchuk noted that the asymmetries measured in M\o ller
scattering polarimeters could be significantly affected by the intrinsic
momenta of the target electrons. This effect is largest in devices with very
small acceptance or very high resolution in laboratory scattering angle. We use
a high resolution po... | physics |
7,242 | Test of Various Photocathodes | hep-ex | A test of various photocathodes was carried out. The tested materials were
CsI, CsTe, their multi-layers and so on. The quantum efficiencies of the
various materials were measured under a vacuum and/or after exposure to several
kinds of gases. | physics |
7,243 | Study of a Threshold Cherenkov Counter Based on Silica Aerogels with Low Refractive Indices | hep-ex | To identify $\pi^{\pm}$ and $K^{\pm}$ in the region of $1.0\sim 2.5$ GeV/c, a
threshold Cherenkov counter equipped with silica aerogels has been
investigated. Silica aerogels with a low refractive index of 1.013 have been
successfully produced using a new technique. By making use of these aerogels as
radiators, we have... | physics |
7,244 | Kinematic Evidence for Top Quark Pair Production in $W+$ Multijet Events in $p \bar p$ Collisions at $\sqrt{s}$~=~1.8 TeV | hep-ex | We present a study of $W+$multijet events that compares the kinematics of the
observed events with expectations from direct QCD $W+$jet production and from
production and decay of top quark pairs. The data were collected in the 1992-93
run with the Collider Detector at Fermilab from 19.3 pb$^{-1}$ of proton-anti
proton... | physics |
7,245 | Feasibility Study of Single-Photon Counting Using a Fine-mesh Phototube for an Aerogel Readout | hep-ex | The fine-mesh phototube is one type of photodetector which can be used under
a strong magnetic field. For an aerogel readout, the single-photon detection
efficiency should be close to 100\% in order to identify particle species. We
carried out a feasibility study of single-photon counting using fine-mesh
phototubes, an... | physics |
7,246 | Measurement of inclusive electron cross section in $γγ$ collisions at TRISTAN | hep-ex | We have studied open charm production in $\gamma \gamma$ collisions with the
TOPAZ detector at the TRISTAN $e^{+}e^{-}$ collider. In this study, charm
quarks were identified by electrons (and positrons) from semi-leptonic decays
of charmed hadrons. The data corresponded to an integrated luminosity of 95.3
pb$^{-1}$ at ... | physics |
7,247 | Measurement of the forward-backward asymmetries for charm- and bottom-quark pair productions at $<\sqrt{s}>$=58GeV with electron tagging | hep-ex | We have measured, with electron tagging, the forward-backward asymmetries of
charm- and bottom-quark pair productions at $<\sqrt{s} >$=58.01GeV, based on
23,783 hadronic events selected from a data sample of 197pb$^{-1}$ taken with
the TOPAZ detector at TRISTAN. The measured forward-backward asymmetries are
$A_{FB}^c =... | physics |
7,248 | J/psi,psi(2S) to mu+ mu- and B to J/psi,psi(2S) Cross Sections | hep-ex | This paper presents a measurement of J/psi,psi(2S) differential cross
sections in p-pbar collisions at square root s = 1.8 TeV. The cross sections
are measured above 4 GeV/c in the central region (|eta| < 0.6) using the dimuon
decay channel. The fraction of events from B decays is measured, and used to
calculate b quar... | physics |
7,249 | $B$ Meson Lifetimes at CDF | hep-ex | Measurements of the $B_u$, $B_d$, and $B_s$ meson lifetime using semileptonic
$B_u \rightarrow e \nu D^0 X, B_d \rightarrow e \nu D^* X, B_s \rightarrow l
\nu D_s X$ events and exclusive $B_u \rightarrow \psi^{(\prime)} K^{(*)}, B_d
\rightarrow \psi^{(\prime)} K^{(*)}_{(s)}, B_s \rightarrow \psi \phi$ events
are presen... | physics |
7,250 | Measurement of inclusive particle spectra and test of MLLA prediction in $e^+e^-$ annihilation at $\sqrt{s}$=58GeV | hep-ex | Inclusive momentum spectra are measured for all charged particles and for
each of $\pi^{\pm}$, $K^{\pm}$, $K^0/\bar{K^0}$, and $p/\bar{p}$ in hadronic
events produced via $e^+e^-$ annihilation at $\sqrt{s}$=58GeV . The measured
spectra are compared with QCD predictions based on the modified leading log
approximation(ML... | physics |
7,251 | Measurement of W and Z Production Cross-sections in p-pbar Collisions at Sqrt(s)=1.8 TeV | hep-ex | The cross sections for W and Z production in p-pbar collisions at sqrt(s)=1.8
TeV are measured using the D0 detector at the Fermilab Tevatron collider. The
detected final states are W->e nu, Z->ee, W->mu nu, and Z->mu mu. In the ratio
of these measurements, many common sources of systematic error cancel and we
measure ... | physics |
7,252 | Measurement of the Bs Meson Lifetime | hep-ex | The lifetime of the $B_s$ meson is measured using the semileptonic decay $B_s
\to D_s^- \ell^+ \nu X$. The data sample consists of 19.3 pb$^{-1}$ of $p
\bar{p}$ collisions at $\sqrt{s} = 1.8$ TeV collected by the CDF detector at
the Fermilab Tevatron collider during 1992-1993. There are $76 \pm 8$ $\ell^{+}
D_s^{-}$ si... | physics |
7,253 | Search for New Particles Decaying to Dijets in p-pbar Collisions at sqrt(s)=1.8 TeV | hep-ex | We have used 19 pb**-1 of data collected with the Collider Detector at
Fermilab to search for new particles decaying to dijets. We exclude at 95%
confidence level models containing the following new particles: axigluons with
mass between 200 and 870 GeV, excited quarks with mass between 80 and 570 GeV,
and color octet ... | physics |
7,254 | Observation of Excess $Λ(\barΛ)$ Production in Two-Photon Processes at TRISTAN | hep-ex | We have carried out inclusive measurements of $\Lambda(\bar{\Lambda})$
production in two-photon processes at TRISTAN. The mean $\sqrt{s}$ was 58 GeV
and the integrated luminosity was 265 pb$^{-1}$. Inclusive $\Lambda
(\bar{\Lambda})$ samples were obtained under such conditions as no-electron,
anti-electron, and remnant... | physics |
7,255 | Measurement of alpha_s(M_Z^2) from Hadronic Event Observables at the Z^0 Resonance | hep-ex | The strong coupling alpha_s(M_Z^2) has been measured using hadronic decays of
Z^0 bosons collected by the SLD experiment at SLAC. The data were compared with
QCD predictions both at fixed order, O(alpha_s^2), and including resummed
analytic formulae based on the next-to-leading logarithm approximation. In this
comprehe... | physics |
7,256 | Electron identification using the TOPAZ detector at TRISTAN | hep-ex | We present an electron-identification method using the time-projection
chamber and the lead-glass calorimeter in the TOPAZ detector system. Using this
method we have achieved good electron identification against hadron backgrounds
over a wide momentum range in the hadronic events produced by both
single-photon exchange... | physics |
7,257 | A TEST OF THE FLAVOR INDEPENDENCE \\[.1in] OF STRONG INTERACTIONS | hep-ex | We present a comparison of the strong couplings of light ($u$,~$d$,~and~$s$),
$c$, and $b$ quarks determined from multijet rates in flavor-tagged samples of
hadronic $Z^0$ decays recorded with the SLC Large Detector at the SLAC Linear
Collider. Flavor separation on the basis of lifetime and decay multiplicity
differenc... | physics |
7,258 | A Search for Jet Handedness in Hadronic $Z^0$ Decays | hep-ex | We have searched for signatures of polarization in hadronic jets from $Z^0
\to q \bar{q}$ decays using the ``jet handedness'' method. The polar angle
asymmetry induced by the high SLC electron-beam polarization was used to
separate quark jets from antiquark jets, expected to be left- and
right-polarized, respectively. ... | physics |
7,259 | A novel approach to error function minimization for feedforward neural networks | hep-ex | Feedforward neural networks with error backpropagation (FFBP) are widely
applied to pattern recognition. One general problem encountered with this type
of neural networks is the uncertainty, whether the minimization procedure has
converged to a global minimum of the cost function. To overcome this problem a
novel appro... | physics |
7,260 | The Charge Asymmetry in W-Boson Decays Produced in p-pbar Collisions at sqrt(s) = 1.8 TeV | hep-ex | The charge asymmetry has been measured using $19,039~W$ decays recorded by
the CDF detector during the 1992-93 run of the Tevatron Collider. The asymmetry
is sensitive to the ratio of $d$ and $u$ quark distributions to $x<0.01$ at
$Q^2 \approx M_W^2$, where nonperturbative effects are minimal. It is found
that of the t... | physics |
7,261 | Mechanical Design of the CDF SVX~II Silicon Vertex Detector | hep-ex | A next generation silicon vertex detector is planned at CDF for the 1998
Tevatron collider run with the Main Injector. The SVX~II silicon vertex
detector will allow high luminosity data-taking, enable online triggering of
secondary vertex production, and greatly increase the acceptance for heavy
flavor physics at CDF. ... | physics |
7,262 | Upsilon Production at CDF | hep-ex | We report on measurements of the Upsilon(1S), Upsilon(2S) and Upsilon(3S)
differential and integrated cross sections in pp(bar) collisions at sqrt(s)=1.8
TeV. The three resonances were reconstructed through the decay
Upsilon-->mu(+)mu(-). The cross section measurements are compared to
theoretical models of direct botto... | physics |
7,263 | Observation of hard scattering in photoproduction events with a large rapidity gap at HERA | hep-ex | Events with a large rapidity gap and total transverse energy greater than 5
GeV have been observed in quasi-real photoproduction at HERA with the ZEUS
detector. The distribution of these events as a function of the $\gamma p$
centre of mass energy is consistent with diffractive scattering. For total
transverse energies... | physics |
7,264 | Measurement of multiplicity and momentum spectra in the current fragmentation region of the Breit frame at HERA | hep-ex | Charged particle production has been measured in Deep Inelastic Scattering
(DIS) events using the ZEUS detector over a large range of $Q^2$ from 10 to
$1280 {\rm\ GeV}^2$. The evolution with $Q$ of the charged multiplicity and
scaled momentum has been investigated in the current fragmentation region of
the Breit frame.... | physics |
7,265 | Time Dependence of Coherent $P^{0}\bar{P}^{0}$ Decays and CP Violation at Asymmetric $B$ Factories | hep-ex | A generic formalism is presented for the time-dependent or time-integrated
decays of any coherent $P^{0}\bar{P}^{0}$ system ($P^{0} = K^{0}, D^{0},
B^{0}_{d}$, or $B^{0}_{s}$). To meet various possible measurements at
asymmetric $B$ factories, we reanalyze some typical signals of CP violation in
the coherent $B^{0}_{d}... | physics |
7,266 | Study of D*(2010)+- Production in ep Collisions at HERA | hep-ex | We report the first observation of charmed mesons with the ZEUS detector at
HERA using the decay channel ${\rm D}^{*+}\rightarrow (\Do \rightarrow {\rm
K}^-\pi^+)\pi^+$ (+ c.c.). Clear signals in the mass difference $\Delta
M$=$M$(D$^*$)--$M$(D$^0)$ as well as in the $M(K\pi)$ distribution at the D$^0$
mass are found. ... | physics |
7,267 | Jet production in high Q^2 deep-inelastic eo scattering at HERA | hep-ex | Two-jet production in deep-inelastic electron-proton scattering has been
studied for $160<Q^2<1280$~GeV$^2$, $0.01<x<0.1$ and $0.04<y<0.95$ with the
ZEUS detector at HERA. The kinematic properties of the jets and the jet
production rates are presented. The partonic scaling variables of the two-jet
system and the rate o... | physics |
7,268 | Measurement of the Decay Asymmetry Parameters in $Λ_c^+ \to Λπ^+$ and $Λ_c^+ \to Σ^+π^0 $ | hep-ex | We have measured the weak decay asymmetry parameters ($\aLC $) for two \LC\
decay modes. Our measurements are $\aLC = -0.94^{+0.21+0.12}_{-0.06-0.06} $ for
the decay mode $\Lambda_c^+ \to \Lambda\pi^+ $ and $\aLC = -0.45\pm 0.31 \pm
0.06$ for the decay mode $\Lambda_c \to \Sigma^+\pi^0 $. By combining these
measurement... | physics |
7,269 | Monte Carlo Studies of a Novel LiF Radiator for RICH Detectors | hep-ex | We show that a multifaceted LiF radiator produces more Cherenkov light and
has better resolution per photon than a flat radiator slab when used in a ring
imaging Cherenkov counter. Such a system is being considered for the CLEO III
upgrade. | physics |
7,270 | Dijet Cross Sections in Photoproduction at HERA | hep-ex | Dijet production by almost real photons has been studied at HERA with the
ZEUS detector. Jets have been identified using the cone algorithm. A cut on xg,
the fraction of the photon energy participating in the production of the two
jets of highest transverse energy, is used to define cross sections sensitive
to the part... | physics |
7,271 | A Measurement of the Proton Structure Function $F_{\!2}(x,Q^2)$ | hep-ex | A measurement of the proton structure function $F_{\!2}(x,Q^2)$ is reported
for momentum transfer squared $Q^2$ between 4.5 $GeV^2$ and 1600 $GeV^2$ and
for Bjorken $x$ between $1.8\cdot10^{-4}$ and 0.13 using data collected by the
HERA experiment H1 in 1993. It is observed that $F_{\!2}$ increases
significantly with d... | physics |
7,272 | A search for massive neutral bosons in orthopositronium decay | hep-ex | We have searched for an exotic decay of orthopositronium into a single photon
and a short-lived neutral boson in the hitherto unexplored mass region above
900 ${\rm keV}/{\it c}^{2}$, by noting that this decay is one of few remaining
candidates which could explain the discrepancy of the orthopositronium
decay-rate. A h... | physics |
7,273 | First Measurement of the Deep--Inelastic Structure of Proton Diffraction | hep-ex | A measurement is presented, using data taken with the H1 detector at HERA, of
the contribution of diffractive interactions to deep-inelastic electron-proton
scattering. The diffractive contribution to the proton structure function is
evaluated as a function of the appropriate deep-inelastic scattering variables
using a... | physics |
7,274 | In-beam Tests of a Ring Imaging Cerenkov Detector With a Multianode Photomultiplier Readout | hep-ex | A ring-imaging \v{C}erenkov counter read out by a 100-channel PMT of active
area 10$\times$10 cm$^2$ was operated successfully in a test beam at the BNL
AGS with several radiator gases, including the heavy fluorocarbon
C$_4$F$_{10}$. Ring radii were measured for electrons, muons, pions and kaons
over the particle momen... | physics |
7,275 | Measurement of the W Boson Mass | hep-ex | We present a measurement of the mass of the $W$ boson using data collected
with the CDF detector during the 1992-93 collider run at the Fermilab Tevatron.
A fit to the transverse mass spectrum of a sample of 3268 {\mbox{$W \rightarrow
\mu\nu$}} events recorded in an integrated luminosity of 19.7 pb$^{-1}$ gives a
mass ... | physics |
7,276 | Charm from Hyperonsin the Future: Fermilab Experiment 781 | hep-ex | Recent results from CERN experiment WA89 have shown that charmed baryons and
particularly charmed-strange baryons have a significant cross section in
$\Sigma^-$ beams. Fermilab experiment 781, which is currently under
construction, will utilize this fact to pursue a broad program of high
statistics studies of charmed b... | physics |
7,277 | Limits on $WWZ$ and $WWγ$ couplings from $WW$ and $WZ$ production in $p\overline{p}$ collisions at $\sqrt{s} = 1.8$ TeV | hep-ex | Direct limits are set on $WWZ$ and $WW\gamma$ three-boson couplings in a
search for $WW$ and $WZ$ production with high transverse momentum in
$p\overline{p}$ collisions at $\sqrt{s} = 1.8$ TeV, using the Collider Detector
at Fermilab. The results are in agreement with the SU(2) $\times$ U(1) model of
electroweak intera... | physics |
7,278 | Measurement of the $ZZγ$ and $Zγγ$ Couplings in $p\bar p$ Collisions at $\sqrt{s} = 1.8$ TeV | hep-ex | We have directly measured the ZZ-gamma and Z-gamma-gamma couplings by
studying p pbar --> l+ l- gamma + X, (l = e, mu) events at the CM energy of
1.8$ TeV with the D0 detector at the Fermilab Tevatron Collider. A fit to the
transverse energy spectrum of the photon in the signal events, based on the
data set correspondi... | physics |
7,279 | Photon Structure, as seen at HERA | hep-ex | At HERA, the electron-proton collider at DESY, Hamburg, the large flux of
almost on-shell photons accompanying the lepton beam is being used to shed new
light on the structure of the photon. Recent results are reviewed and
discussed, with emphasis on those aspects of the photon's nature which should
be understandable u... | physics |
7,280 | Search for $W$ boson pair production in $p\bar{p}$ collisions at $\sqrt{s}~=~1.8~$~TeV | hep-ex | The results of a search for $W$ boson pair production in $p\bar{p}$
collisions at $\sqrt{s}=1.8$ TeV with subsequent decay to dilepton ($e\mu, ee
$, and $\mu\mu$) channels are presented. One event is observed with an expected
background of $0.56\pm0.13$ events with an integrated luminosity of
approximately 14 pb$^{-1}$... | physics |
7,281 | Measurement of the $B$ Meson Differential Cross Section, $dσ/dp_T$, in $p\bar{p}$ Collisions at $\sqrt{s} = 1.8$ TeV | hep-ex | This paper presents the first direct measurement of the $B$ meson
differential cross section, $d\sigma/dp_T$, in $p\bar{p}$ collisions at
$\sqrt{s}=1.8$ TeV using a sample of $19.3 \pm 0.7$ pb$^{-1}$ accumulated by
the Collider Detector at Fermilab (CDF). The cross section is measured in the
central rapidity region $|y... | physics |
7,282 | Inclusive transverse momentum distributions of charged particles in diffractive and non--diffractive photoproduction at HERA | hep-ex | Inclusive transverse momentum spectra of charged particles in photoproduction
events in the laboratory pseudorapidity range $-1.2<\eta<1.4$ have been
measured up to $p_{T}=8\GeV $ using the ZEUS detector. Diffractive and
non--diffractive reactions have been selected with an average $\gamma p$ centre
of mass (c.m.) ener... | physics |
7,283 | Measurement of the Cross Section for the Reaction $γp \to \jpsi~p$ with the ZEUS Detector at HERA | hep-ex | This paper reports the cross section measurements for the process ep
$\rightarrow$ e~\jpsi~p for $Q^2 < 4$ GeV$^2$ at $\sqrt s = 296$ GeV, based on
an integrated luminosity of about 0.5~pb$^{-1}$, using the ZEUS detector. The
\jpsi~was detected in its $\rm e^{+}e^{-}$ and $\rm \mu^{+}\mu^{-}$ decay
modes. The photoprod... | physics |
7,284 | Measurement of Charged and Neutral Current $e^-p$ Deep Inelastic Scattering Cross Sections at High $Q^2$ | hep-ex | Deep inelastic $e^-p$ scattering has been studied in both the charged-current
(CC) and neutral-current (NC) reactions at momentum transfers squared, $Q^2$,
between 400 GeV$^2$ and the kinematic limit of 87500 GeV$^2$ using the ZEUS
detector at the HERA $ep$ collider. The CC and NC total cross sections, the NC
to CC cro... | physics |
7,285 | First Results from the BELLE DIRC Prototype | hep-ex | The DIRC (Detection of Internally Reflected Cerenkov light) is a new type of
ring imaging Cerenkov detector, which detects images from Cerenkov light
produced in precisely machined quartz bars. The Cerenkov images are transported
along several meters of bar to the edge of the detector where they are
proximity focussed ... | physics |
7,286 | The Structure Function Ratios F2(Li)/F2(D) and F2(C)/F2(D) at small x | hep-ex | We present the structure function ratios F2(Li)/F2(D) and F2(C)/F2(D)
measured in deep inelastic muon-nucleus scattering at a nominal incident muon
energy of 200 GeV. The kinematic range 0.0001 < x < 0.7 and 0.01< Q^2 < 70
GeV^2 is covered. For values of $x$ less than $0.002$ both ratios indicate
saturation of shadowin... | physics |
7,287 | Inclusive Parton Cross Sections in Photoproduction and Photon Structure | hep-ex | Photoproduction of 2-jet events is studied with the H1 detector at HERA.
Parton cross sections are extracted from the data by an unfolding method using
leading order parton-jet correlations of a QCD generator. The gluon
distribution in the photon is derived in the fractional momentum range $0.04\le
x_\gamma \le 1$ at t... | physics |
7,288 | A Measurement of the Branching Ratio and Form Factor of K_L->mu mu gamma | hep-ex | We report on a measurement of the decay $K_L\rightarrow\mu^+\mu^-\gamma$ from
Fermilab experiment E799. We observe $207$ candidate signal events with an
estimated background of $10.5 \pm 4.0$ events and establish
$B(K_L\rightarrow\mu^+\mu^-\gamma) = (3.23\pm 0.23(stat) \pm 0.19(sys))\times
10^{-7}$. This provides the f... | physics |
7,289 | hepawk, Version 1.6: A Language for Scanning High Energy Physics Events | hep-ex | This manual describes version 1.6 of the programming language hepawk,
designed for convenient scanning of data structures arising in the simulation
of high energy physics events. The interpreter for this language has been
implemented in FORTRAN77, therefore hepawk runs on any machine with a FORTRAN77
compiler. | physics |
7,290 | Leptoquarks and Compositeness Scales from a Contact Interaction Analysis of Deep Inelastic $e^\pm \, p$ Scattering at HERA | hep-ex | A contact interaction analysis is presented to search for new phenomena
beyond the Standard Model in deep inelastic $e^\pm p \rightarrow e^\pm \,
hadrons$ scattering. The data are collected with the H1 detector at HERA and
correspond to integrated luminosities of $0.909 \ {\rm pb}^{-1}$ and $2.947 \
{\rm pb}^{-1}$ for ... | physics |
7,291 | Results from the LSND Neutrino Oscillation Search | hep-ex | The Liquid Scintillator Neutrino Detector (LSND) at the Los Alamos Meson
Physics Facility sets bounds on neutrino oscillations in the appearance channel
nu_mu_bar --> nu_e_bar by searching for the signature of the reaction nu_e_bar
p --> e^+ n: an e$^+$ followed by a 2.2MeV gamma ray from neutron capture. Five
e^{+/-} ... | physics |
7,292 | A liquid-helium cooled large-area silicon PIN photodiode x-ray detector | hep-ex | An x-ray detector using a liquid-helium cooled large-area silicon PIN
photodiode has been developed along with a tailor-made charge sensitive
preamplifier whose first-stage JFET has been cooled. The operating temperature
of the JFET has been varied separately and optimized. The x- and $\gamma$-ray
energy spectra for an... | physics |
7,293 | Study of the photon remnant in resolved photoproduction at HERA | hep-ex | Photoproduction at HERA is studied in $ep$ collisions, with the ZEUS
detector, for $\gamma p$ centre-of-mass energies ranging from 130-270 GeV. A
sample of events with two high-$p_T$ jets ($p_T > 6$ GeV, $\eta <1.6$) and a
third cluster in the approximate direction of the electron beam is isolated
using a clustering al... | physics |
7,294 | An Ultrahigh-Statistics Charm Experiment for the Year $\sim2000$ | hep-ex | After reviewing the motivation for high-statistics charm studies, we describe
a fixed-target experiment capable of reconstructing $>10^8$ charm decays. Such
an experiment can test the Standard Model and probe non-Standard physics
through sensitive searches for such phenomena as D0 mixing, CP violation, and
FCNC decays. | physics |
7,295 | A Study of the Fragmentation of Quarks in $e^-p$ Collisions at HERA | hep-ex | Deep inelastic scattering (DIS) events, selected from 1993 data taken by the
H1 experiment at HERA, are studied in the Breit frame of reference. The
fragmentation function of the quark is compared with those of \ee data. It is
shown that certain aspects of the quarks emerging from within the proton in \ep
interactions ... | physics |
7,296 | Neural Network based Electron Identification in the ZEUS Calorimeter | hep-ex | We present an electron identification algorithm based on a neural network
approach applied to the ZEUS uranium calorimeter. The study is motivated by the
need to select deep inelastic, neutral current, electron proton interactions
characterized by the presence of a scattered electron in the final state. The
performance... | physics |
7,297 | Momentum Correlations of Charmed Pairs Produced in $π^{-}-Cu$ Interactions at 230 GeV/c | hep-ex | We study the production characteristics of 557 pairs of charmed hadrons
produced in $\pi^{-}-Cu$\ interactions at 230~GeV/c using a momentum estimator
for charmed hadrons with missing decay products. We find, the mean value of the
transverse momentum squared of the charmed pairs is $<$\pts$>=(1.98\pm 0.11\pm
0.09)\;$ G... | physics |
7,298 | Shadowing in Inelastic Scattering of Muons on Carbon, Calcium and Lead at Low XBj | hep-ex | Nuclear shadowing is observed in the per-nucleon cross-sections of positive
muons on carbon, calcium and lead as compared to deuterium. The data were taken
by Fermilab experiment E665 using inelastically scattered muons of mean
incident momentum 470 GeV/c. Cross-section ratios are presented in the
kinematic region 0.00... | physics |
7,299 | Measurement of the $WWγ$ gauge boson couplings in $p\bar{p}$ Collisions at $\sqrt{s}=1.8$ TeV | hep-ex | The $WW\gamma$ gauge boson couplings were measured using $p\bar{p}\to
\ell\nu\gamma+X$ ($\ell=e,\mu$) events at $\sqrt{s}=1.8$ TeV observed with the
{D\O} detector at the Fermilab Tevatron Collider. The signal, obtained from the
data corresponding to an integrated luminosity of $13.8 {\rm pb}^{-1}$, agrees
well with th... | physics |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.