Weak phase gamma and strong phase delta from CP averaged B ->pi pi and pi K decays
Weak phase gamma and strong phase delta from CP averaged B ->pi pi and pi K decays
复制标题
CP 平均 B ->pi pi 和 pi K 衰减的弱相位 gamma 和强相位 delta
DOI：
10.1103/physrevd.62.036007
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发表时间：
2000
影响因子：
5
通讯作者：
Yu
中科院分区：
文献类型：
--
作者：
Yue;Yu
假设四种衰变模式B-->pi（-）pi（+），pi（0）pi（+），pi（-）K（+），pi（-）K（）在bar（0）上的强相SU（3）对称性，并忽略这些衰变中相对较小的电弱企鹅效应，弱相γ和强相δ可由四种衰变模式的CP平均分支比以模型无关的方式确定。看来，目前的实验数据B--> π π和π K衰变倾向于负的cos γ cos δ值。通过结合来自bar（d，s）（0）混合上的V-u B B-d，s（0）-（B）的其他约束以及标准模型内的间接CP违反参数k（K），发现相位γ和δ的两个有利的解位于小于或类似于γ的35度和小于或类似于δ的106度的区域中类似于180度或86度，小于或类似于γ，小于或类似于151度，以及0度小于或类似于δ，小于或类似于75度，在1西格马标准偏差内。应注意，如果允许数据的标准偏差大于1西格玛，则两个解可以接近一个解，其中对于相位γ和δ具有大得多的区域。B -->pi（-）K（+）衰变中的直接CP不对称性α（π”）（（pi-K+））可以与目前的实验上限一样大。B-->pi（-）pi（+）衰变中的直接CP不对称性a（π“）（（pi+）pi-）在1 σ水平上可以达到高达约40%。
Assuming SU(3) symmetry for the strong phases in the four decay modes B-->pi(-)pi(+), pi(0)pi(+), pi(-)K(+), pi(-)(K) over bar(0) and ignoring the relative small electroweak penguin effects in those decays, the weak phase gamma and the strong phase delta can be determined in a model independent way by the CP averaged branching ratios of the four decay modes. It appears that the current experimental data for B-->pi pi and pi K decays prefer a negative value of cos gamma cos delta. By combining with the other constraints from V-ub B-d,s(0)-(B) over bar(d,s)(0) mixing, and the indirect CP-violating parameter epsilon(K) within the standard model, two favorable solutions for the phases gamma and delta are found to lie in the region 35 degrees less than or similar to gamma less than or similar to 62 degrees and 106 degrees less than or similar to delta less than or similar to 180 degrees or 86 degrees less than or similar to gamma less than or similar to 151 degrees and 0 degrees less than or similar to delta less than or similar to 75 degrees within 1 sigma standard deviation. It is noted that if allowing the standard deviation of the data to be more than 1 sigma, the two solutions could approach one solution with a much larger region for the phases gamma and delta. Direct CP asymmetry a(epsilon")((pi-K+)) in B -->pi(-)K(+) decay can be as large as the present experimental upper bound. Direct CP asymmetry a(epsilon")((pi+)pi-) in B-->pi(-)pi(+) decay can reach up to about 40% at the 1 sigma level.