标题： $B \to X_s γ$是否等于$b \to s γ$? 稀有整体B衰变中的旁观者贡献 显示英文标题

标题： Is $B \to X_s γ$ equal to $b \to s γ$ ? Spectator contributions to rare inclusive B decays

摘要： 在$B \to X_s \gamma $中，存在微扰的$QCD$修正，在阶数$\alpha_s$上不仅对单夸克线过程$ b \to s \gamma$有影响，还来自一组图，其中弱相互作用顶点涉及一个与 B 介子中的探测夸克相互作用的胶子。我们讨论了这些图的全部集合的影响。这些图可以影响衰变率以及光子谱的线形，因为它们比纯探测夸克衰变$b \to s \gamma$更倾向于产生较软的光子能量。这些图的一个子集会导致带电和中性 B 的衰变率差异，$B^+ \to X_s \gamma$对$B^0 \to X_s \gamma$，这可以在实验上进行搜索，尽管我们的计算表明这种效应很难观察到。 束缚态效应被证明是产生在$\alpha_s$阶次的衰变率的旁观者修正所必需的。 总速率的相应贡献相当小（大约为$5 \% $），尽管在光子谱的某些部分该效应要大一些。 显示英文摘要

摘要： In $B \to X_s \gamma $ there are perturbative $QCD$ corrections at order $\alpha_s$ not only to the single quark line process $ b \to s \gamma$ but also coming from a set of diagrams where the weak interaction vertex involves a gluon which interacts with the spectator quark in the B hadron. We discuss the impact of the full set of these diagrams. These can influence the decay rate and also the line shape of the photon spectrum as they favor a softer photon energy than does the pure spectator decay $b \to s \gamma$. A subset of these diagrams generate differences in the decay rates for charged and neutral B's , $B^+ \to X_s \gamma$ vs. $B^0 \to X_s \gamma$ which can be searched for experimentally, although our calculation indicates that the effect will be hard to observe. Bound state effects turn out to be required to give rise to spectator corrections to the decay rate at order $\alpha_s$. The resulting contribution to the total rate is rather small (of about $5 \% $ ), although the effect is somewhat larger on portions of the photon spectrum.