论文标题
$ b^ - \ to k^+k^-π^ - $和$ b^ - \toπ^+π^-π^ - $衰减中的分支分数和违反CP
Branching Fractions and CP Violation in $B^-\to K^+K^-π^-$ and $B^-\to π^+π^-π^-$ Decays
论文作者
论文摘要
我们在这项工作中介绍了$ b $ ersons的树为主的无魅力的三体衰减，$ b^ - \ to k^+k^-π^ - $和$ b^ - \toπ^+π^+π^-π^ - $，在分解方法中。主要结果是：（i）有两个不同的非共振贡献来源：一个来自$ b \ to u $树的过渡，另一个来自标量密度的非共振矩阵元素$ \ langle m_1m_1m_2 | \ bar q_1 q_1 q_1 q_1 q_1 q_1 q_1 q_1 q_2 | 0 \ rangle^rangle^{\ rm rm nr nr nr nr nr nr nr nr nr nr nr nr nr nr nr nr nr} $。事实证明，即使是针对树木主导的三体衰变，主要的非共振贡献源自企鹅图，而不是从$ b \ $ $ $ tree的过程中，正如最近在$π^-K^-k^-k^+$系统中观察到的大型非共振组件所暗示的那样，这是$ b^ - \ b^ - \ k^to K^ - \ k^tok^+k^+k^-out k^-Fuse的三分之一。 （ii）$ b^ - \至f_2（1270）π^ - \ to k^+k^-π^ - $的计算分支分数比LHCB小于$ \ sim 7 $，其中心价值为$ \ sim 7 $，但预测的$ \ b（b^ - \ to f_2（f_2（f_2（1270））（1270）（1270）plansist us and plansants us and plansitys us and plansitys us and plansants usanty的数据^ - \ iS usanty plansyt usanty。从这两个过程的LHCB测量值中提取的$ b^ - \至f_2（1270）π^ - $的分支分数也差异为七个！因此，$ f_2（1270）$对$ b^ - \ to k^+k^-π^ - $的贡献很大程度上是在实验上被高估了。包括$ 1/m_b $ $从QCD分解（QCDF）推断出的企鹅歼灭的功率校正，这是$ F_2（1270）$组成部分中的32 \％的可观CP不对称性，与实验一致。 （iii）$ b^ - \toπ^+π^-π^ - $的$ρ（1450）$组件的5 \％分数符合理论期望。但是，$ b^ - \ to k^+k^-π^ - $的大量分数为30 \％，这是完全出乎意料的。将来需要澄清这个问题。
We present in this work a study of tree-dominated charmless three-body decays of $B$ mesons, $B^-\to K^+K^-π^-$ and $B^-\toπ^+π^-π^-$, within the factorization approach. The main results are: (i) There are two distinct sources of nonresonant contributions: one arises from the $b\to u$ tree transition and the other from the nonresonant matrix element of scalar densities $\langle M_1M_2|\bar q_1 q_2|0\rangle^{\rm NR}$. It turns out that even for tree-dominated three-body decays, dominant nonresonant contributions originate from the penguin diagram rather than from the $b\to u$ tree process, as implied by the large nonresonant component observed recently in the $π^- K^+$ system which accounts for one third of the $B^-\to K^+K^-π^-$ rate. (ii) The calculated branching fraction of $B^-\to f_2(1270)π^-\to K^+K^-π^-$ is smaller than the LHCb by a factor of $\sim 7$ in its central value, but the predicted $\B(B^-\to f_2(1270)π^-\toπ^+π^-π^-)$ is consistent with the data. Branching fractions of $B^-\to f_2(1270)π^-$ extracted from the LHCb measurements of these two processes also differ by a factor of seven! Therefore, it is likely that the $f_2(1270)$ contribution to $B^-\to K^+K^-π^-$ is largely overestimated experimentally. Including $1/m_b$ power corrections from penguin annihilation inferred from QCD factorization (QCDF), a sizable CP asymmetry of 32\% in the $f_2(1270)$ component agrees with experiment. (iii) A fraction of 5\% for the $ρ(1450)$ component in $B^-\toπ^+π^-π^-$ is in accordance with the theoretical expectation. However, a large fraction of 30\% in $B^-\to K^+K^-π^-$ is entirely unexpected. This issue needs to be clarified in the future.
