B s → P V衰变中湮灭图和硬旁观者散射效应

Probing Spectator Scattering and Annihilation Corrections in Bs→PV Decays

摘要: 利用 LHC b 实验组对衰变 B-0s → K* π - 和 B-0s → K ± K*∓ 分支比的测量结果, 在 Q C D 因子化( Q C -D F ) 框架下, 采用最小 x 2 方法拟合 X i, fA, 并将 B u .d → P V 衰变拟合出的湮灭参数代入 B s → P V 衰变的可观测量中进行理论计算和分析 . 研究发现, 对于 B s 和 B u .d 介子系统湮灭参数 Xi , fA( P V )具有普适性 . 对于 B r ( B-0s →K *+ π - )和 B r ( B-0s → K ± K*∓ )这两个可观测量, 给出的理论值与 LHC b 给出的实验值在误差范围内保持一致, 只有湮灭图贡献的 B-0s → π ρ 衰变对于研究湮灭参数有着重要的作用 .

Abstract: Motivated by the measurements on Br(B-0s→π－K*+)and Br(B-0s→K±K*) by LHCb collaboration, a χ2-fit on the parameters Xi,fA was performed within QCD factorization (QCDF) framework. The observables of Bs→PVdecays were calculated and analyzed by considering the end-point parameters gotten from Bu,d→PV as input parameters. It was found that the universalities of Xi,fA(PV) for the Bu,d,s→PV decay modes were allowed, the theoretical results of Br(B-0s→K*+π－) and Br(B-0s→K±K*) were corresponding with the LHCb data, and the pure annihilation decays B-0s→πρ is important for exploring the annihilation corrections.