Measurement of the BS 0 meson lifetime using semileptonic decays
Physical Review D - Particles, Fields, Gravitation and Cosmology 59:3 (1999) 1-14
Abstract:
The lifetime of the BS0 meson is measured using the semileptonic decay BS0→DS-l+νX. The data sample consists of about 110 pb-1 of pp̄ collisions at √s=1.8 TeV collected by the CDF detector at Fermilab. Four different DS- decay modes are reconstructed resulting in approximately 600 DS-l+ signal events. The BS0 meson lifetime is determined to be τ(BS0)=(1.36±0.09-0.05+0.06) ps, where the first and second uncertainties are statistical and systematic, respectively. The BS0 meson decay length distribution is examined for a lifetime difference ΔΓ/Γ between the two mass eigenstates of the BS0 meson. An upper limit of ΔΓ/Γ<0.83 is set at the 95% confidence level.Measurement of the mass splittings between the bb̄χb,J(1P) states
Physical Review D Particles Fields Gravitation and Cosmology 59:3 (1999) 1-5
Abstract:
We present new measurements of photon energies and branching fractions for the radiative transitions Y(2S)→γχAn aging study by semi-conductive microstrip gas chambers11Submitted for 1998 Symposium on Radiation Measurements and Applications, 12–14 May 1998, Ann Arbor, Michigan.
Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment Elsevier 422:1-3 (1999) 282-285
Aging study of a gas electron multiplier detector with microstrip gas chamber readout
IEEE Nuclear Science Symposium and Medical Imaging Conference 1 (1999) 598-602
Abstract:
The aging behavior of wire chambers have been of great interest for many years. Recently a new generation of proportional chambers have been developed including the microstrip gas chamber (MSGC) microgap chamber (MGC) and gaseous electron multiplier (GEM). Aging studies of these detectors are of particular interest to the LHC (Large Hadron Collider) community because the baseline design of the CMS experiment includes MSGCs as part of the tracking system. We have performed an aging study of a GEM detector readout with a MSGC. The GEM is constructed from Kapton and copper, the MSGC is constructed from semiconductive glass and gold. When the detector is operated in argon and dimethyl ether (DME) gas mixture and irradiated with a 6 KeV photon beam, about 220 mC/cm of charge can be accumulated without degradation of the detector performance. This corresponds to about 20 years of operation at the LHC.Event-building and PC farm based Level-3 trigger at the CDF experiment
Institute of Electrical and Electronics Engineers (IEEE) (1999) 28-32