Study of B~0_(s→фф→)KKKK with the CMS Phase II Detector

摘要

72.1 Introduction In the Standard Model (SM) the decay B~0_s→фф (with ф→K~+K~-) proceeds predominantly via a b→ s{- under letter s}s penguin amplitude (cf. Fig. 72.1). The first evidence for this decay was obtained by the CDF experiment at the Tevatron [1]. To date, the most precise determination of the phase ф_s= -0.17 ± 0.15_(stat) ± 0.03_(syst) was performed by the LHCb experiment, based on approximately 4000 B~0_s candidates [2, 3]. In the SM, ф_s in the decay B~0_s →фф is expected to be very small: QCD factorization calculations provide an upper limit of фs < 0.02 [4-6].