QCD因子化框架下Β_s→PP衰变中湮灭图效应

CDF和LHCb实验组对Bs介子衰变中纯湮灭过程的测量揭示了大湮灭图贡献的存在.基于日益精确的B介子衰变测量实验结果,本文在QCD因子化框架下研究了湮灭图贡献的效应,对Bs系统中的湮灭图参数空间进行了拟合,并结合Bu,d介子衰变分析了湮灭图贡献对初态的味道依赖性.在本文得到的参数空间内,Bs→ππ,πK,KK衰变的理论结果与实验数据一致.然而,在目前的理论计算和实验精度下,湮灭图参数对初态味道的依赖性很难被严格辨别,即ΧiA对Bs和Bu,d系统仍可以是普适的.

The Research of Annihilation Effect in B_s→PPDecays within QCDF

The most recent experimental results for the pure annihilation Bsdecay measured by CDF and LHCb Collaborations reveal existence of unexpected large annihilation contribution.Based on the updated measurements on B-meson decays,we study the annihilation contribution within QCD factorization approach and perform a global fit for the annihilation parameters in Bssystem.Moreover,combining the results in Bu,dsystem,we analyze the dependence of these parameters on the initial states.With the values of best-fit points as inputs,our theoretical results of Bs→ππ,πK,KKdecays agree well with the experimental data.However,because of the large experimental errors and theoretical uncertainties,the flavor dependence of annihilation parametersΧiAis hardly to be confirmed,In other words,which implies that XiAcan still be universal for Bsand Bu,dsystems.