Measurement of the mass of the Bs 0 meson
Physical Review D - Particles, Fields, Gravitation and Cosmology 53:7 (1996) 3496-3505
Abstract:
We measure the mass of the B0s meson by reconstructing the decay chain B0s→J/ψφ, J/ψ→µ+µ-, and φ→K+K-. The data are obtained from 19.3 pb-1 of integrated luminosity of pp collisions at √s=1.8 TeV using the Collider Detector at Fermilab. A sample of 80 000 inclusive J/ψ→µ+µ- events is used to study systematic biases in track reconstruction and to calibrate the momentum scale. We reconstruct the kinematically similar decays B+→J/ψK+ and B0→J/ψK*0 to study the mass measurement technique used for the B0s meson. Based on the observation of 32 ± 6 candidates, the mass of the B0s meson is measured to be 5369.9 ± 2.3 ± 1.3 MeV/c2 and the mass difference between B0s and the average mass of B+ and B0 is determined to be 89.7 ± 2.7 ± 1.2 MeV/c2. © 1996 The American Physical Society.Modeling evaporative cooling in phase space using a direct simulation of the Monte Carlo method
Conference on Quantum Electronics and Laser Science QELS Technical Digest Series 9 (1996) 228-229
Abstract:
A simulation of the forced evaporative cooling process is made using a classical Monte Carlo method. This powerful method is complementary to other recent studies of evaporative cooling and does not need the assumption that a gas has recovered thermal equilibrium after each cut of potential well or the assumption of sufficient ergodicity. Direct simulation by Bird's method can be done in any arbitrary potential and can be used to study the deviation between three components of translational temperature during forced evaporation.Properties of jets in Z boson events from 1.8 TeV ¯p p collisions
Physical Review Letters 77:3 (1996) 448-453
Abstract:
We present a study of events with Z bosons and hadronic jets produced in ¯p p collisions at a center-of-mass energy of 1.8 TeV. The data consist of 6708 Z → e+e- decays from 106pb-1 of integrated luminosity collected using the CDF detector at the Fermilab Tevatron Collider. The Z+ ≥ n jet cross sections and jet production properties have been measured for n = 1 to 4. The data are compared to predictions of leading-order QCD matrix element calculations with added gluon radiation and simulated parton fragmentation. © 1996 The American Physical Society.Pulsed sub-recoil laser cooling of atoms
Journal of Optics B: Quantum and Semiclassical Optics 8:5 (1996) 983-988
Abstract:
In this paper we propose a new and simple velocity selective method, which combines the velocity selective coherent population trapping of atoms in a light field and the kinetic energy coupling between the dark state and coupled state(s) during free flight, in order to reach a very narrow momentum distribution in a short period of time. This technique combined with force-assisted velocity selective coherent population trapping can produce very efficient cooling and trapping. It can also be used to overcome the cooling limit caused by the leakage of the dark state.Quantum jump calculations of subrecoil cooling in one and two dimensions
Conference on Quantum Electronics and Laser Science (QELS) - Technical Digest Series 9 (1996) 201