94362727
Studies of radiation damage to CAMEX64 preamplifiers exposed to gamma -rays at the Cornell High Energy Synchrotron Source
CAMEX64 preamplifiers, developed for use in the readout of silicon strip detectors, have been exposed to well-measured doses of monochromatic gamma -rays from the Cornell High Energy Synchrotron Source (CHESS), and measurements of the resulting radiation damage have been made. Silicon strip detectors with their associated CAMEXes will be installed close to the interaction region in the CLEO experiment at Cornell University, where they will be exposed to both charged particle and photon fluences. Powered and unpowered CAMEXes were irradiated and after each exposure measurements of pedestals, gains, and coherent and incoherent noise were made until the devices could no longer be read out. Results are presented for noise and gain degradation as a function of dose. Using well-controlled and calibrated 20 keV synchrotron radiation, failure begins at 20 krad in powered CAMEXes and between 60 and 120 krad in unpowered CAMEXes. These failure levels are considerably larger than the projected radiation dose.<<ETX>>
14586426
Review of New Rare Hadronic B-decay Results
We present a new result from Belle and many new results from BABAR for rare hadronic B decays. These include measurements of decays involving baryons, a Dalitz plot analysis of the three-charged-kaon system, many new results for B decays to eta'X and omegaX, and a limit for the decay B-> a_1 rho. Measurements of the vector-vector decays B->rhoKstar and B->omegaKstar are helping to understand the value of the longitudinal polarization fraction for these B->VV decays.
15188676
Calibration and performance of the MARK II drift chamber vertex detector
We have calibrated and studied the performance of the MARK II drift chamber vertex detector with cosmic ray tracks collected with the chamber inside the MARK II detector at the SLC. The chamber achieves 30 {mu}m impact parameter resolution and 500 {mu}m track-pair resolution using CO{sub 2}/C{sub 2}H{sub 6}H{sub 6}(92/8) at 2 atmospheres pressure. The chamber has successfully recorded Z{sup 0} decays at the SLC, and resolved tracks in dense hadronic jets with good efficiency and high accuracy. 5 refs., 13 figs.
122233998
Comparison and summary of tau topological branching fractions
After nearly two decades of work on topological branching fractions, it appears that an experimental consensus is forming. The new world average is 14.54 ± 0.20.
17397470
Inclusive decays of B mesons to charmonium.
We have used the CLEO-II detector at the Cornell Electron Storage Ringe (CESR) to study the inclusive production of charmonium mesons in a sample of 2.15 million {ital B{bar B}} events. We find inclusive branching fractions of (1.12{plus_minus}0.04{plus_minus}0.06)% for {ital B}{r_arrow}{ital J}/{psi}{ital X}, (0.34{plus_minus}0.04{plus_minus}0.03)% for {ital B}{r_arrow}{psi}{prime}{ital X}, and (0.40{plus_minus}0.06{plus_minus}0.04)% for {ital B}{r_arrow}{chi}{sub {ital c}1}{ital X}. We also find some evidence for the inclusive production of {chi}{sub {ital c}2}, and set an upper limit for the branching fraction of the inclusive decay {ital B}{r_arrow}{eta}{sub {ital c}}{ital X} of 0.9% at 90% confidence level. Momentum spectra for inclusive {ital J}/{psi}, {psi}{prime}, and {chi}{sub {ital c}1} production are presented. These measurements are compared to theoretical calculations.
121273996
A study of double tagged two-photon reactions at spear☆
Abstract We have identified 262 doubly tagged two-photon events. A subset of the data shows an enhancement of 21 events in the inclusive two-photon mass squared distribution between 0.8 and 2.2 GeV 2 . If these events result from spin 2 resonance production then Γ γγ = 9.5 ± 3.9 ± 2.4 keV (statistical and systematic). From another subset of 58 events in which the final state could be classified we determine the two-photon hadron to muon cross section ratio R γγ = 1.1 ± 0.3 ± 0.3.
118976257
Quarks and Antiquarks in Nuclei
The Chiral Quark-Soliton model provides the quark and antiquark substructure of the nucleon, which is embedded in nuclear matter. This provides a new way to asses the effects of the nuclear medium on the nucleon. We calculate nuclear binding and saturation, describe the European Muon Collaboration (EMC) effect consistently with Drell-Yan experiments, and predict modifications to the polarized parton distributions. We also calculate the electromagnetic form factors of a bound proton, and find significant modifications of the electromagnetic form factors in the nuclear environment. In every case, the properties of the sea of quark-antiquark pairs in the nucleon are very important, and serve to mitigate the valence quark effect. The changes in the sea quarks when the nucleon is immersed in the nuclear medium are the primary mode by which consistency is maintained with experimental constraints (Drell-Yan data, magnetic moment), while still maintaining a significant effect needed to explain the deep inelastic scattering and polarization transfer data.
14067577
NLO corrections to differential cross sections for pseudo-scalar Higgs boson production
Abstract We have computed the full next-to-leading (NLO) QCD corrections to the differential distributions d 2 σ/(dp T dy) for pseudo-scalar Higgs (A) production at large hadron colliders. This calculation has been carried out using the effective Lagrangian approach which is valid as long as the mass of the pseudo-scalar Higgs boson m A and its transverse momentum p T do not exceed the top-quark mass  m t . The shape of the distributions hardly differ from those obtained for scalar Higgs (H) production because, apart from the overall coupling constant and mass, there are only small differences between the partonic differential distributions for scalar and pseudo-scalar production. Therefore, there are only differences in the magnitudes of the hadronic differential distributions which can be mainly attributed to the unknown mixing angle β describing the pseudo-scalar Higgs coupling to the top quarks.
121531502
QCD corrections to heavy flavour photoproduction and electroproduction
We investigate the QCD corrections to the total cross sections and single-particle inclusive differential distributions for γ + p → Q(Q) + X and e + p → e + Q(Q) + X. In the latter reaction we assume that the exchanged photon is almost real (Weizsacker-Williams approximation). This requires the calculation of the O(αs) corrections to the photon-parton reaction γ + g → Q + Q including the virtual gluon contributions and the soft and hard gluon radiation in the reaction γ + g → Q + Q + g. The contributions from γ + q(q) → Q + Q + q(q) are also calculated. We give exact results for the O(α2αS2) total cross sections and single particle inclusive differential distribution for b-quark production at HERA. Results for b- and t- production at future ep colliders (the LEP∗LHC option at CERN) are also presented.
122638824
QCD Corrections to Heavy Quark Production in p anti-p Collisions
We investigate QCD corrections to the cross section and differential distributions for $p+\overline{p}\ensuremath{\rightarrow}Q+\overline{Q}+X$, where $Q$ and $\overline{Q}$ are heavy quarks. We calculate the order-${\ensuremath{\alpha}}_{s}$ corrections to the parton reaction $g+g\ensuremath{\rightarrow}Q+\overline{Q}$. At the quark level this involves the computation of the virtualgluon contributions to the reactions $g+g\ensuremath{\rightarrow}Q+\overline{Q}$, and the soft and hard contributions from the reaction $g+g\ensuremath{\rightarrow}Q+\overline{Q}+g$. Results are given for the cross section and differential distributions for the range of $p\overline{p}$ collision energies available at CERN and Fermilab. A comparison is made with the recent data from the UA1 Collaboration.
123015361
Electromagnetic production of trimuons in muon scattering: Bethe-Heitler reactions with muon and heavy-lepton pairs
We analyze the Bethe-Heitler production of muon and heavy-lepton pairs using high-energy muon beams on a variety of targets. We give results for coherent production from a nucleus, for incoherent production from individual protons and neutrons, and for deep-inelastic production. Differential distributions are presented for the final leptons and the effects of experimental cuts are considered. This work complements our previous study of trimuon production via muon radiation, Compton radiation, and hadronic final-state interactions.