Measurement of the associated γ+μ± production cross section in pp̄ collisions at √s=1.8 TeV
Physical Review D Particles Fields Gravitation and Cosmology 60:9 (1999) 1-5
Abstract:
We present the first measurement of associated direct photon+muon production in hadronic collisions, from a sample of 1.8 TeV pp collisions recorded with the Collider Detector at Fermilab. Quantum chromodynamics (QCD) predicts that these events are primarily from the Compton scattering process cg→cγ, with the final state charm quark producing a muon. Hence this measurement is sensitive to the charm quark content of the proton. The measured cross section of 29±9 pb is compared to a leading-order QCD parton shower model as well as a next-to-leading-order QCD calculation. ©1999 The American Physical Society.Measurement ofB 0 − B 0 flavor oscillations using jet-charge and lepton flavor tagging inp p ¯ collisions ats = 1.8 TeV
Physical Review D American Physical Society (APS) 60:7 (1999) 072003
Measurement of the Bd 0B̄d 0 oscillation frequency using dimuon data in pp̄ collisions at √s = 1.8 TeV
Physical Review D - Particles, Fields, Gravitation and Cosmology 60:5 (1999) 1-6
Abstract:
We present a measurement of the mass difference Δmd of the two Bd0 mass eigenstates. We use a flavor tagging method based on the lepton charge, in a sample of events with two muons at low transverse momentum. The sample corresponds to an integrated luminosity of 90 pb-1 collected by the Collider Detector at Fermilab. The result obtained is Δmd=0.503±0.064(stat)±0.071(syst) ps-1. ©1999 The American Physical Society.Measurements of photomultiplier single photon counting efficiency for the Sudbury Neutrino Observatory
Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 432:2-3 (1999) 364-373
Abstract:
A knowledge of the absolute efficiency of the photomultiplier tubes (PMTs) used in the Sudbury Neutrino Observatory (SNO) is important for modelling the behaviour of the detector. While the quantum efficiencies for the PMTs are known, the efficiency in single-photon counting mode (which includes collection efficiency and counting efficiency) is of more relevance. A calibration of the 8 in. Hamamatsu R1408 photomultipliers in this mode requires a known flux of incident light at the very low level of 10-16 W cm-2 (250 photons cm-2 s-1). A method of performing such measurements, utilising the extreme linearity obtainable with silicon photodiodes, is presented in this paper. The results of efficiency measurements on four PMTs are given and a comparison is made with previous results obtained using a Cherenkov source of known intensity.Kinematics of tt¯ events at CDF
Physical Review D American Physical Society (APS) 59:9 (1999) 092001