AI 中文总结
该研究引入$B$衰变标记能量关联器（BTEC），推导含光子贡献的端点$B$衰变因子化关系，计算单圈精度喷注函数，可用于改进信号-背景区分。
AI 中文摘要
我们引入了$B$衰变标记能量关联器（BTEC），以解析 inclusive $B$衰变在端点区域的能量流角结构，重点关注$\bar B\to X_s\to\boldsymbol{\text{γ}}$的直接光子贡献。在领头幂次和自然共线角标度$\tau\boldsymbol{\text{~}}s\boldsymbol{\text{~}}Q\boldsymbol{\text{Λ}}_{\text{QCD}}$下，我们推导了一个因子化关系，涉及标准硬系数、$B$介子形状函数以及新测量的夸克喷注函数，未引入新的领头幂次非微扰函数。我们计算了测量的喷注函数至单圈精度，并验证其角积分可复现标准 inclusive 夸克喷注函数。对于Bosch--Lange--Neubert--Paz中心参数集，一个示例基准显示在固定角截断$\tau_c\boldsymbol{=}\boldsymbol{2}\boldsymbol{-}\boldsymbol{4}\boldsymbol{\text{GeV}}^2$外存在$3\boldsymbol{-}\boldsymbol{16}\boldsymbol{\text{%}}$的迁移。结合独立约束的形状函数，角累积量对领头幂次端点因子化进行了闭合测试，且对直接$O_7$幂次修正和分辨光子效应敏感。因此，BTEC在普通光子谱之外提供了 inclusive 反冲喷注角结构的信息，当信号与背景的能量流分布不同时，可改进信号-背景区分能力。
英文摘要
We introduce a $B$-decay tagged energy correlator (BTEC) to resolve the angular structure of energy flow in inclusive $B$ decays in the endpoint region, focusing on the direct-photon contribution to $\overline B\to X_sγ$. At leading power and at the natural collinear angular scale $τ\sim s\sim QΛ_{\rm QCD}$, we derive a factorization relation involving the standard hard coefficient and $B$-meson shape function together with a new measured quark jet function; no new leading-power nonperturbative function is introduced. We calculate the measured jet function at one-loop accuracy and verify that its angular integral reproduces the standard inclusive quark jet function. For the central Bosch--Lange--Neubert--Paz parameter set, an illustrative benchmark gives $3 - 16\%$ migration outside the fixed angular cuts $τ_c=2 - 4~{\rm GeV}^2$. With an independently constrained shape function, the angular cumulatives provide a closure test of leading-power endpoint factorization and are sensitive to direct-$O_7$ power corrections and resolved-photon effects. The BTEC thereby adds information on the angular structure of the inclusive recoil jet beyond the ordinary photon spectrum and may improve signal--background discrimination when their energy-flow profiles differ.
Comments23 pages, 5 figures, 1 table
