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.Event-building and PC farm based Level-3 trigger at the CDF experiment
Institute of Electrical and Electronics Engineers (IEEE) (1999) 28-32
IR limits, pregalactic stars, neutrino decay and quantum gravity
Astroparticle Physics 11:1-2 (1999) 103-109
Abstract:
The results of recent studies which seek to probe fundamental aspects of astrophysics using TeV gamma-ray observations of active galactic nuclei (AGN) are presented. These analyses take advantage of both spectral and temporal information together with the unique combination of the very high energies and large distance scales involved. The next generation of instruments currently planned are expected to make substantial improvements in the study of such phenomena. © 1999 Elsevier Science B.V. All rights reserved.Limits to quantum gravity effects on energy dependence of the speed of light from observations of tev flares in active galaxies
Physical Review Letters 83:11 (1999) 2108-2111
Abstract:
We have used data from a TeV gamma-ray flare associated with the active galaxy Markarian 421 to place bounds on the possible energy dependence of the speed of light in the context of an effective quantum gravitational energy scale. Recent theoretical work suggests that such an energy scale could be less than the Planck mass and perhaps as low as 10^16 GeV. The limits derived here indicate this energy scale to be in excess of 4×106 GeV for at least one approach to quantum gravity in the context of D-brane string theory. To the best of our knowledge this constitutes the first convincing limit on such phenomena in this energy regime. © 1999 The American Physical Society.Kinematics of t(t)over-bar events at CDF -: art. no. 092001
PHYSICAL REVIEW D 59:9 (1999) ARTN 092001