Study of substructure of high transverse momentum jets produced in proton-antiproton collisions at s=1.96 TeV
Physical Review D American Physical Society (APS) 85:9 (2012) 091101
Evidence for the charmless annihilation decay mode B(s)(0)→π(+)π(-).
Physical review letters 108:21 (2012) 211803
Abstract:
We search for annihilation decay modes of neutral b mesons into pairs of charmless charged hadrons with the upgraded Collider Detector at the Fermilab Tevatron. Using a data sample corresponding to 6 fb(-1) of integrated luminosity, we obtain the first evidence for the B(s)(0)→π(+)π(-) decay, with a significance of 3.7σ, and a measured branching ratio B(B(s)(0)→π(+)π(-))=(0.57±0.15(stat)±0.10(syst))×10(-6). A search for the B(0)→K(+)K(-) mode in the same sample yields a significance of 2.0σ, and a central value estimate B(B(0)→K(+)K(-))=(0.23±0.10(stat)±0.10(syst))×10(-6).Measurement of Bs0→Ds(*)+Ds(*)- branching ratios.
Physical review letters 108:20 (2012) 201801
Abstract:
The decays Bs0→Ds(*)+Ds(*)- are reconstructed in a data sample corresponding to an integrated luminosity of 6.8 fb-1 collected by the CDF II detector at the Tevatron pp[over ¯] collider. All decay modes are observed with a significance of more than 10σ, and we measure the Bs0 production rate times Bs0→Ds(*)+Ds(*)- branching ratios relative to the normalization mode B0→Ds+D-to be 0.183±0.021±0.017 for Bs0→Ds+Ds-, 0.424±0.046±0.035 for Bs0→Ds*±Ds^∓, 0.654±0.072±0.065 for Bs0→Ds*+Ds*-, and 1.261±0.095±0.112 for the inclusive decay Bs0→Ds(*)+Ds(*)-, where the uncertainties are statistical and systematic. These results are the most precise single measurements to date and provide important constraints for indirect searches for nonstandard model physics in Bs0 mixing.Search for a dark matter candidate produced in association with a single top quark in pp collisions at √[s]=1.96 TeV.
Physical review letters 108:20 (2012) 201802
Abstract:
We report a new search for dark matter in a data sample of an integrated luminosity of 7.7 fb-1 of Tevatron pp[over ¯] collisions at √[s]=1.96 TeV, collected by the CDF II detector. We search for production of a dark-matter candidate, D, in association with a single top quark. We consider the hadronic decay mode of the top quark exclusively, yielding a final state of three jets with missing transverse energy. The data are consistent with the standard model; we thus set 95% confidence level upper limits on the cross section of the process pp[over ¯]→t+D as a function of the mass of the dark-matter candidate. The limits are approximately 0.5 pb for a dark-matter particle with mass in the range of 0-150 GeV/c2.Search for a heavy particle decaying to a top quark and a light quark in pp ¯ collisions at √s=1.96 TeV.
Physical review letters 108:21 (2012) 211805