Measurement of ratios of fragmentation fractions for bottom hadrons in pp虅 collisions at s=1.96TeV
Physical Review D - Particles, Fields, Gravitation and Cosmology 77:7 (2008)
Abstract:
This paper describes the first measurement of b-quark fragmentation fractions into bottom hadrons in Run II of the Tevatron Collider at Fermilab. The result is based on a 360pb-1 sample of data collected with the CDF II detector in pp虅 collisions at s=1.96TeV. Semileptonic decays of B虅0, B-, and B虅s0 mesons, as well as 螞b0 baryons, are reconstructed. For an effective bottom hadron pT threshold of 7GeV/c, the fragmentation fractions are measured to be fu/fd=1.054卤0.018(stat)-0.045+0.025(sys)卤0. 058(B), fs/(fu+fd)=0.160卤0.005(stat)-0.010+0.011(sys)-0.034+0.057(B), and f螞b/(fu+fd)=0.281卤0.012(stat)-0.056+0.058(sys)-0.087+0.128(B), where the uncertainty B is due to uncertainties on measured branching ratios. The value of fs/(fu+fd) agrees within one standard deviation with previous CDF measurements and the world average of this quantity, which is dominated by LEP measurements. However, the ratio f螞b/(fu+fd) is approximately twice the value previously measured at LEP. The approximately 2蟽 discrepancy is examined in terms of kinematic differences between the two production environments. 漏 2008 The American Physical Society.Measurement of Lifetime and Decay-Width Difference in B_{s};{0}-->J/psivarphi Decays.
Phys Rev Lett 100:12 (2008) 121803
Abstract:
We measure the mean lifetime tau=2/(Gamma_{L}+Gamma_{H}) and the decay-width difference DeltaGamma=Gamma_{L}-Gamma_{H} of the light and heavy mass eigenstates of the B_{s}{0} meson, B_{sL}{0} and B_{sH}{0}, in B_{s}{0}-->J/psivarphi decays using 1.7 fb;{-1} of data collected with the CDF II detector at the Fermilab Tevatron pp[over ] collider. Assuming CP conservation, a good approximation for the B_{s}{0} system in the standard model, we obtain DeltaGamma=0.076_{-0.063}{+0.059}(stat)+/-0.006(syst) ps{-1} and tau=1.52+/-0.04(stat)+/-0.02(syst) ps, the most precise measurements to date. Our constraints on the weak phase and DeltaGamma are consistent with CP conservation.Evidence for D0-D虅0 mixing using the CDF II detector
Physical Review Letters 100:12 (2008)
Abstract:
We measure the time dependence of the ratio of decay rates for the rare decay D0鈫扠+蟺- to the Cabibbo-favored decay D0鈫扠-蟺+. A signal of 12.7脳103 D0鈫扠+蟺- decays was obtained using the Collider Detector at Fermilab II detector at the Fermilab Tevatron with an integrated luminosity of 1.5fb-1. We measure the D0-D虅0 mixing parameters (RD,y鈥,x鈥2) , and find that the data are inconsistent with the no-mixing hypothesis with a probability equivalent to 3.8 Gaussian standard deviations. 漏 2008 The American Physical Society.Measurement of lifetime and decay-width difference in Bs0鈫扟/蠄 decays
Physical Review Letters 100:12 (2008)
Abstract:
We measure the mean lifetime 蟿=2/(螕L+螕H) and the decay-width difference 螖螕=螕L-螕H of the light and heavy mass eigenstates of the Bs0 meson, BsL0 and BsH0, in Bs0鈫扟/蠄 decays using 1.7fb-1 of data collected with the CDF II detector at the Fermilab Tevatron pp虅 collider. Assuming CP conservation, a good approximation for the Bs0 system in the standard model, we obtain 螖螕=0.076-0.063+0. 059(stat)卤0.006(syst)ps-1 and 蟿=1.52卤0.04(stat)卤0. 02(syst)ps, the most precise measurements to date. Our constraints on the weak phase and 螖螕 are consistent with CP conservation. 漏 2008 The American Physical Society.Observation of exclusive dijet production at the Fermilab Tevatron p虅p collider
Physical Review D - Particles, Fields, Gravitation and Cosmology 77:5 (2008)