Evidence for the exclusive decay Bc±→J/ψπ± and measurement of the mass of the Bc± meson
Physical Review Letters 96:8 (2006)
Abstract:
We report the first evidence for a fully reconstructed decay mode of the Bc± meson in the channel Bc±→J/ψπ±, with J/ψ→μ+μ-. The analysis is based on an integrated luminosity of 360pb-1 in pp̄ collisions at 1.96 TeV center of mass energy collected by the Collider Detector at Fermilab. We observe 14.6±4.6 signal events with a background of 7.1±0.9 events, and a fit to the J/ψπ± mass spectrum yields a Bc± mass of 6285.7±5.3(stat)±1. 2(syst)MeV/c2. The probability of a peak of this magnitude occurring by random fluctuation in the search region is estimated as 0.012%. © 2006 The American Physical Society.Experimental study of χb(2P)→ππχb(1P)
Physical Review D American Physical Society (APS) 73:1 (2006) 012003
GridPP: Development of the UK computing Grid for particle physics
Journal of Physics G: Nuclear and Particle Physics 32:1 (2006)
Abstract:
The GridPP Collaboration is building a UK computing Grid for particle physics, as part of the international effort towards computing for the Large Hadron Collider. The project, funded by the UK Particle Physics and Astronomy Research Council (PPARC), began in September 2001 and completed its first phase 3 years later. GridPP is a collaboration of approximately 100 researchers in 19 UK university particle physics groups, the Council for the Central Laboratory of the Research Councils and CERN, reflecting the strategic importance of the project. In collaboration with other European and US efforts, the first phase of the project demonstrated the feasibility of developing, deploying and operating a Grid-based computing system to meet the UK needs of the Large Hadron Collider experiments. This note describes the work undertaken to achieve this goal. © 2006 IOP Publishing Ltd.Measurement of the dipion mass spectrum in X(3872)→J/ψπ+π- decays
Physical Review Letters 96:10 (2006)
Abstract:
We measure the dipion mass spectrum in X(3872)→J/ψπ+π- decays using 360pb-1 of p̄p collisions at s=1.96TeV collected with the CDFÂ II detector. The spectrum is fit with predictions for odd C-parity (S13, P11, and DJ3) charmonia decaying to J/ψπ+π-, as well as even C-parity states in which the pions are from ρ0 decay. The latter case also encompasses exotic interpretations, such as a D0D̄*0 molecule. Only the S13 and J/ψρ hypotheses are compatible with our data. Since S13 is untenable on other grounds, decay via J/ψρ is favored, which implies C=+1 for the X(3872). Models for different J/ψ-ρ angular momenta L are considered. Flexibility in the models, especially the introduction of ρ-ω interference, enables good descriptions of our data for both L=0 and 1. © 2006 The American Physical Society.Measurement of the inclusive jet cross section using the kT algorithm in pp̄ collisions at s=1.96TeV
Physical Review Letters 96:12 (2006)