Amplitude analyses of the decays χ c1 →ηπ +π - and χ c1 →η ′π +π -
Physical Review D - Particles, Fields, Gravitation and Cosmology 84:11 (2011)
Abstract:
Using a data sample of 2.59×107 ψ(2S) decays obtained with the CLEO-c detector, we perform amplitude analyses of the complementary decay chains ψ(2S)→γχ c1; χ c1→ηπ +π - and ψ(2S)→γχ c1; χ c1→η ′π +π -. We find evidence for an exotic P-wave η ′π amplitude, which, if interpreted as a resonance, would have parameters consistent with the π 1(1600) state reported in other production mechanisms. We also make the first observation of the decay a 0(980) →η ′π and measure the ratio of branching fractions B(a 0(980)→η ′π)/B(a 0(980) →ηπ)=0.064±0.014±0.014. The ππ spectrum produced with a recoiling η is compared to that with η ′ recoil. © 2011 American Physical Society.Measurement of the Bs0 lifetime in fully and partially reconstructed Bs0→Ds-(Φπ-)X decays in p̄p collisions at √s=1.96TeV
Physical Review Letters 107:27 (2011)
Abstract:
We present a measurement of the Bs0 lifetime in fully and partially reconstructed Bs0→Ds-(Φπ-)X decays in 1.3fb-1 collected in pp̄ collisions at √s=1.96TeV by the CDF II detector at the Fermilab Tevatron. We measure τ(Bs0)=1.518±0.041(stat)±0. 027(syst)ps. The ratio of this result and the world average B0 lifetime yields τ(Bs0)/τ(B0)=0.99±0.03, which is in agreement with recent theoretical predictions. © 2011 American Physical Society.Search for a vectorlike quark with charge 2/3 in t+Z events from pp collisions at √s=7TeV
Physical Review Letters 107:27 (2011)
Abstract:
A search for pair-produced heavy vectorlike charge-2/3 quarks, T, in pp collisions at a center-of-mass energy of 7 TeV, is performed with the CMS detector at the LHC. Events consistent with the flavor-changing-neutral-current decay of a T quark to a top quark and a Z boson are selected by requiring two leptons from the Z-boson decay, as well as an additional isolated charged lepton. In a data sample corresponding to an integrated luminosity of 1.14fb -1, the number of observed events is found to be consistent with the standard model background prediction. Assuming a branching fraction of 100% for the decay T→tZ, a T quark with a mass less than 475GeV/c 2 is excluded at the 95% confidence level. © 2011 CERN.Search for a heavy toplike quark in pp̄ collisions at √s=1.96TeV
Physical Review Letters 107:26 (2011)
Abstract:
We present the results of a search for pair production of a heavy toplike (t′) quark decaying to Wq final states using data corresponding to an integrated luminosity of 5.6fb-1 collected by the CDF II detector in pp̄ collisions at √s=1.96TeV. We perform parallel searches for t′→Wb and t′→Wq (where q is a generic down-type quark) in events containing a lepton and four or more jets. By performing a fit to the two-dimensional distribution of total transverse energy versus reconstructed t′ quark mass, we set upper limits on the t′t̄′ production cross section and exclude a standard model fourth-generation t ′ quark decaying to Wb (Wq) with mass below 358 (340)GeV/c2 at 95% C.L. © 2011 American Physical Society.Measurement of polarization and search for CP violation in Bs 0→φφ decays
Physical Review Letters 107:26 (2011)