B_s→PV衰变中湮灭图和硬旁观者散射效应

利用LHCb实验组对衰变B~0_s→K*π~-和B_-~0s→K~±K~(*■)分支比的测量结果 ,在QCD因子化(QCDF)框架下,采用最小x~2方法拟合Xi,fA,并将B_(u.d)→PV衰变拟合出的湮灭参数代入B_s→PV衰变的可观测量中进行理论计算和分析.研究发现,对于Bs和B_(u.d)介子系统湮灭参数Xi,fA(PV)具有普适性.对于Br(B~0_s→K*+π~-)和Br(B~0_s→K±K(*■))这两个可观测量,给出的理论值与LHCb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~0_s→πρ衰变对于研究湮灭参数有着重要的作用.

Probing Spectator Scattering and Annihilation Corrections in B_s →PV Decays

Motivated by the measurements on Br(B~0_s →π-K*+)and Br(B~0_s → K±K~(*■))by LHCb collaboration,aχ~2-fit on the parameters Xi,fAwas performed within QCD factorization(QCDF)framework.The observables of B_s →PVdecays were calculated and analyzed by considering the end-point parameters gotten fromBu,d →PVas input parameters.It was found that the universalities of Xi,fA(PV)for the B_(u,d,s )→ PVdecay 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.