FIRST EVIDENCE FOR B_s → φφ AND PENGUIN B DECAYS AT CDf

摘要

We present the first evidence of the decay mode B_s → φφ and a measurement of partial width and direct CP asymmetry for the B~+→φK~+ decay using 180 pb~(-1) of data collected by the CDF II experiment at the Fermilab Tevatron collider. We measure: BR(B_s → φφ) = (1.4 ± 0.6(stat.) ± 0.2(syst.) ± 0.5(BR)) • 10~(-5), where the last error is due to the uncertainty on the B_s → J/ψφ branching ratio used as normalization, BR(B~+ → φK~+) = (7.2 ± 1.3(stat.) ± 0.7(syst.)) • 10~(-6) and A_(CP)(B~+ → φK~+) = — 0.07±0.17(stat.) _(-0.05)~(+0.06)(syst.). We also briefly discuss prospects for studying other charmless B → VV decays at CDF.