微扰QCD因子化方法下B^(0)_(d,s)→K^(*)K^(*)的研究  

The study of B^(0)_(d,s)→K^(*)K^(*) decays in the perturbative QCD approach

作　　者：孙艳军 赵国华 王斌 王琛 SUN Yan-jun;ZHAO Guo-hua;WANG Bin;WANG Chen(College of Physics and Electronic Engineering,Northwest Normal University,Lanzhou 730070,Gansu,China)

机构地区：[1]西北师范大学物理与电子工程学院,甘肃兰州730070

出　　处：《西北师范大学学报（自然科学版）》2022年第3期53-61,134,共10页Journal of Northwest Normal University(Natural Science)

基　　金：国家自然科学基金资助项目(11365018,11375240)。

摘　　要：利用微扰QCD因子化方法计算了B^(0)→K^(*+)K^(*-)、B^(0)→K^(*0)K^(*0)、B^(0)_(s)→K^(*+)K^(*-)、B^(0)_(s)→K^(*0)K^(*0)的衰变分支比、直接CP破坏、纵向极化分数等实验观测量,并与QCD因子化方法的计算结果以及实验值进行比较.发现对于企鹅图算符为主的过程,螺旋度翻转可以破坏简单因子化的幂次规则.此外,对于发射图为主的过程,分支比和极化分数对B介子波函数和硬散射核能标比较敏感.对直接CP破坏相关物理量进行了预言,希望在未来的实验中得到检验.The branching ratios,the direct CP asymmetries and the longitudinal polarization fractions of the decays B^(0)→K^(*+)K^(*-)、B^(0)→K^(*0)K^(*0)、B^(0)_(s)→K^(*+)K^(*-)、B^(0)_(s)→K^(*0)K^(*0) are studied by using perturbative QCD approach,and the calculated results were compared with the predicted values of QCD factorization approach and the experimental data.It's found that for the decays governed by the penguin operators,the power counting in the naive factorization could be violated by the helicity flip.Moreover,for the decays dominated by the emission diagrams,both the branching ratios and the longitudinal polarization fractions are heavily sensitive to the wave function of B meson and the scales in the hard kernels.The other direct CP asymmetries observables are also calculated,which could be tested in the future.

关 键 词：微扰QCD方法 分支比 极化分数 

分 类 号：O413.3[理学—理论物理]