Dalitz plot analysis of Ds+→K+K-π+
Physical Review D - Particles, Fields, Gravitation and Cosmology 79:7 (2009)
Abstract:
We perform a Dalitz plot analysis of the decay Ds+→K+K-π+ with the CLEO-c data set of 586pb-1 of e+e- collisions accumulated at s=4.17GeV. This corresponds to about 0.57×106 Ds±Ds* pairs from which we select 14400 candidates with a background of roughly 15%. In contrast to previous measurements we find good agreement with our data only by including an additional f0(1370)π+ contribution. We measure the magnitude, phase, and fit fraction of K*(892)0K+, (1020)π+, K0*(1430)K+, f0(980)π+, f0(1710)π+, and f0(1370)π+ contributions and limit the possible contributions of other KK and Kπ resonances that could appear in this decay. © 2009 The American Physical Society.Measurement of the top quark mass at CDF using the "neutrino ø weighting" template method on a lepton plus isolated track sample
Physical Review D - Particles, Fields, Gravitation and Cosmology 79:7 (2009)
Abstract:
We present a measurement of the top quark mass with tt̄ dilepton events produced in pp̄ collisions at the Fermilab Tevatron (s=1.96TeV) and collected by the CDF II detector. A sample of 328 events with a charged electron or muon and an isolated track, corresponding to an integrated luminosity of 2.9fb-1, are selected as tt̄ candidates. To account for the unconstrained event kinematics, we scan over the phase space of the azimuthal angles (ν1,ν2) of neutrinos and reconstruct the top quark mass for each ν1, ν2 pair by minimizing a χ2 function in the tt̄ dilepton hypothesis. We assign χ2-dependent weights to the solutions in order to build a preferred mass for each event. Preferred mass distributions (templates) are built from simulated tt̄ and background events, and parametrized in order to provide continuous probability density functions. A likelihood fit to the mass distribution in data as a weighted sum of signal and background probability density functions gives a top quark mass of 165.5-3.3+3.4(stat)±3. 1(syst)GeV/c2. © 2009 The American Physical Society.New measurement of exclusive decays of the χc0 and χc2 to two-meson final states
Physical Review D - Particles, Fields, Gravitation and Cosmology 79:7 (2009)
Abstract:
Using a sample of 2.59×107 ψ(2S) decays collected by the CLEO-c detector, we present results of a study of χc0 and χc2 decays into two-meson final states. We present the world's most precise measurements of the χcJ,(J=0,2)→π+π-, π0π0, K+K-, KS0KS0, ηη, and η′η′ branching fractions, and a search for χc decays into ηη′. These results shed light on the mechanism of charmonium decays into pseudoscalar mesons. © 2009 The American Physical Society.Powerful jets from accreting black holes: Evidence from the optical and infrared
Chapter in Black Holes and Galaxy Formation, (2009) 295-320