从深度非弹性散射到重味半轻子衰变：从格点量子色动力学到多强子末态的总速率
From deep inelastic scattering to heavy-flavor semi-leptonic decays: Total rates into multi-hadron final states from lattice QCD
摘要：
我们提出了一种新的技术提取衰变和过渡率到最终状态与任何数量的强子。该方法只对总速率敏感，其中包括具有给定QCD量子数的所有外态。对于涉及光子或轻子的过程，也可以提取关于非强子运动学的微分速率。我们的方法涉及到构建一个有限体积的欧几里得四点函数，其相应的光谱函数测量的衰减和过渡率在无限体积的限制。这需要解决从相关器中提取谱函数的逆问题，并且还需要平滑过程，以便存在定义良好的无限体积极限。这两个步骤都是由巴科斯-吉尔伯特方法完成的，正如我们用数值例子所示，在多个开放衰变通道的情况下，可以预期合理的精度。潜在的应用包括核子结构函数和深层非弹性散射制度的开始，以及半轻子$D$和$B$衰变率。
英文摘要：
We present a new technique for extracting decay and transition rates into final states with any number of hadrons. The approach is only sensitive to total rates, in which all out-states with a given set of QCD quantum numbers are included. For processes involving photons or leptons, differential rates with respect to the non-hadronic kinematics may also be extracted. Our method involves constructing a finite-volume Euclidean four-point function, whose corresponding spectral function measures the decay and transition rates in the infinite-volume limit. This requires solving the inverse problem of extracting the spectral function from the correlator and also necessitates a smoothing procedure so that a well-defined infinite-volume limit exists. Both of these steps are accomplished by the Backus-Gilbert method and, as we show with a numerical example, reasonable precision can be expected in cases with multiple open decay channels. Potential applications include nucleon structure functions and the onset of the deep inelastic scattering regime, as well as semi-leptonic $D$ and $B$ decay rates.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
