Measurement of resonance parameters of orbitally excited narrow B0 mesons.
Phys Rev Lett 102:10 (2009) 102003
Abstract:
We report a measurement of resonance parameters of the orbitally excited (L=1) narrow B0 mesons in decays to B;{(*)+}pi;{-} using 1.7 fb;{-1} of data collected by the CDF II detector at the Fermilab Tevatron. The mass and width of the B_{2};{*0} state are measured to be m(B_{2};{*0})=5740.2_{-1.8};{+1.7}(stat)-0.8+0.9(syst) MeV/c;{2} and Gamma(B_{2};{*0})=22.7_{-3.2};{+3.8}(stat)-10.2+3.2(syst) MeV/c;{2}. The mass difference between the B_{2};{*0} and B10 states is measured to be 14.9_{-2.5};{+2.2}(stat)-1.4+1.2(syst) MeV/c;{2}, resulting in a B10 mass of 5725.3_{-2.2};{+1.6}(stat)-1.5+1.4(syst) MeV/c;{2}. This is currently the most precise measurement of the masses of these states and the first measurement of the B_{2};{*0} width.Search for high-mass resonances decaying to dimuons at CDF.
Phys Rev Lett 102:9 (2009) 091805
Abstract:
We present a search for high-mass neutral resonances using dimuon data corresponding to an integrated luminosity of 2.3 fb(-1) collected in pp[over ] collisions at sqrt[s]=1.96 TeV by the CDF II detector at the Fermilab Tevatron. No significant excess above the standard model expectation is observed in the dimuon invariant-mass spectrum. We set 95% confidence level upper limits on sigmaBR(pp-->X-->micromicro), where X is a boson with spin-0, 1, or 2. Using these cross section limits, we determine lower mass limits on sneutrinos in R-parity-violating supersymmetric models, Z' bosons, and Kaluza-Klein gravitons in the Randall-Sundrum model.Improved measurement of absolute branching fraction of Ds+→τ+ν τ
Physical Review D - Particles, Fields, Gravitation and Cosmology 79:5 (2009)
Abstract:
We have studied the leptonic decay Ds+→τ+ντ, via the decay channel τ+→e+νeν̄τ, using a sample of tagged Ds+ decays collected near the Ds*±Ds peak production energy in e+e- collisions with the CLEO-c detector. We obtain B(Ds+→τ+ντ)=( 5.30±0.47±0.22)% and determine the decay constant fDs=(252.5±11.1± 5.2)MeV, where the first uncertainties are statistical and the second are systematic. © 2009 The American Physical Society.Measurement of B(Ds+→l+ν) and the decay constant fDs+ from 600 pb-1 of e+e- annihilation data near 4170 MeV
Physical Review D - Particles, Fields, Gravitation and Cosmology 79:5 (2009)
Abstract:
We examine e+e-→Ds-Ds*+ and Ds*-Ds+ interactions at 4170 MeV using the CLEO-c detector in order to measure the decay constant fDs+ with good precision. Previously our measurements were substantially higher than the most precise lattice based QCD calculation of (241± 3)MeV. Here we use the Ds+→+ν channel, where the + designates either a μ+ or a τ+, when the τ+→π+ν̄. Analyzing both modes independently, we determine B(Ds+→μ+ν)=( 0.565±0.045±0.017)%, and B(Ds+→τ+ν)=(6.42±0.81± 0.18)%. We also analyze them simultaneously to find an effective value of Beff(Ds+→μ+ν)=(0.591± 0.037±0.018)% and fDs+=( 263.3±8.2±3.9)MeV. Combining with the CLEO-c value determined independently using Ds+→τ+ν, τ+→e+νν̄ decays, we extract fDs+=( 259.5±6.6±3.1)MeV. Combining with our previous determination of B(D+→μ+ν), we extract the ratio fDs+/fD+=1.26±0.06±0.02. No evidence is found for a CP asymmetry between Γ(Ds+→μ+ν) and Γ(Ds-→μ-ν); specifically the fractional difference in rates is measured to be (4.8±6.1)%. Finally, we find B(Ds+→e+ν)<1.2×10-4 at 90% confidence level. © 2009 The American Physical Society.Measurement of cross sections for b jet production in events with a Z boson in pp̄ collisions at s=1.96TeV
Physical Review D - Particles, Fields, Gravitation and Cosmology 79:5 (2009)