Measurement of branching ratio and Bs0 lifetime in the decay Bs0→J/ψf0(980) at CDF

14 páginas, 11 figuras, 2 tablas.-- CDF Collaboration: et al.
We present a study of Bs0 decays to the CP-odd final state J/ψf0(980) with J/ψ→μ+μ- and f0(980)→π+π-. Using pp̅ collision data with an integrated luminosity of 3.8 fb-1 collected by the CDF II detector at the Tevatron we measure a Bs0 lifetime of τ(Bs0→J/ψf0(980))=1.70-0.11+0.12(stat)±0.03(syst)ps. This is the first measurement of the Bs0 lifetime in a decay to a CP eigenstate and corresponds in the standard model to the lifetime of the heavy Bs0 eigenstate. We also measure the product of branching fractions of Bs0→J/ψf0(980) and f0(980)→π+π- relative to the product of branching fractions of Bs0→J/ψϕ and ϕ→K+K- to be Rf0/ϕ=0.257±0.020(stat)±0.014(syst), which is the most precise determination of this quantity to date.
This work was supported by the U.S. Department of Energy and National Science Foundation; the Italian Istituto Nazionale di Fisica Nucleare; the Ministry of Education, Culture, Sports, Science and Technology of Japan; the Natural Sciences and Engineering Research Council of Canada; the National Science Council of the Republic of China; the Swiss National Science Foundation; the A. P. Sloan Foundation; the Bundesministerium für Bildung und Forschung, Germany; the Korean World Class University Program, the National Research Foundation of Korea; the Science and Technology Facilities Council and the Royal Society, UK; the Institut National de Physique Nucleaire et Physique des Particules/ CNRS; the Russian Foundation for Basic Research; the Ministerio de Ciencia e Innovación, and Programa Consolider-Ingenio 2010, Spain; the Slovak R&D Agency; and the Academy of Finland.