New measurements of Cabibbo-suppressed decays of mesons with the CLEO-c detector.
Physical review letters 96:8 (2006) 081802
Abstract:
Using of data collected with the CLEO-c detector, we report on first observations and measurements of Cabibbo-suppressed decays of D mesons in the following six decay modes: pi+ pi- pi0 pi0, pi+ pi+ pi- pi- pi0, pi+ pi0 pi0, pi+ pi+ pi- pi0, eta pi0, and omega pi+ pi-. Improved branching fraction measurements in eight other multipion decay modes are also presented. The measured D --> pi pi rates allow us to extract the ratio of isospin amplitudes A(DeltaI = (3/2) / A(DeltaI = (1/2)) = 0.420 +/- 0.014(stat) +/- 0.016(syst) and the strong phase shift of delta1 = (86.4 +/- 2.8 +/- 3.3) degrees, which is quite large and now more precisely determined.Observation of psi(3770) --> pi pi J/psi and measurement of Gamma ee[psi(2S)].
Physical review letters 96:8 (2006) 082004
Abstract:
We observe signals for the decays psi(3770) --> XJ/psi from data acquired with the CLEO detector operating at the CESR e+ e- collider with square root of s = 3773 MeV. We measure the following branching fractions Beta(psi(3770) --> XJ/psi and significances: (189 +/- 20 +/- 20) x 10(-5) (11.6sigma) for X = pi+ pi-, (80 +/- 25 +/- 16) x 10(-5) (3.4sigma) for X = pi0 pi0, and (87 +/- 33 +/- 22) x 10(-5) (3.5sigma) for X = eta, where the errors are statistical and systematic, respectively. The radiative return process e+ e- --> gamma psi(2S) populates the same event sample and is used to measure Gamma ee[psi(2S)] = (2.54 +/- 0.03 +/- 0.11) keV.Top quark mass measurement using the template method in the lepton+jets channel at CDF II
Physical Review D - Particles, Fields, Gravitation and Cosmology 73:3 (2006)
Abstract:
This article presents a measurement of the top quark mass using the CDF II detector at Fermilab. Colliding beams of protons and antiprotons at Fermilab's Tevatron (s=1.96TeV) produce top/antitop pairs, which decay to W+W-bb̄; events are selected where one W decays to hadrons and the other W decays to either e or μ plus a neutrino. The data sample corresponds to an integrated luminosity of approximately 318pb-1. A total of 165 tt̄ events are separated into four subsamples based on jet transverse energy thresholds and the number of b jets identified by reconstructing a displaced vertex. In each event, the reconstructed top quark invariant mass is determined by minimizing a χ2 for the overconstrained kinematic system. At the same time, the mass of the hadronically decaying W boson is measured in the same event sample. The observed W boson mass provides an in situ improvement in the determination of the hadronic jet energy scale. A simultaneous likelihood fit of the reconstructed top quark masses and the W boson invariant masses in the data sample to distributions from simulated signal and background events gives a top quark mass of 173.5-3.8+3.9GeV/c2. © 2006 The American Physical Society.Search for Z'--> e^+e^- Using Dielectron Mass and Angular Distribution
ArXiv hep-ex/0602045 (2006)
Measurement of the Top Quark Mass using Template Methods on Dilepton Events in Proton-Antiproton Collisions at sqrt(s)=1.96 TeV
ArXiv hep-ex/0602008 (2006)