论文标题
共振$ k^*$的辐射衰减和$γk\ tokπ$振幅从晶格qCD
Radiative decay of the resonant $K^*$ and the $γK \to K π$ amplitude from lattice QCD
论文作者
论文摘要
我们介绍了该过程$γk\ tokπ$的第一个计算，其中出现了狭窄的$ k^*$ vector resonance。使用一个晶格，乳头的质量为284 MeV，我们确定$（q^2，e_ {kπ}）$平面中128点的过渡幅度，并找到合适的谐振散射描述。我们证明，在将晶格QCD计算的有限体积矩阵元素转换为物理相关的Infinite-Infinite-Infinite-Infinite-Infinite-Infinite-Infinite-Infimume矩阵元素时，即使我们主要对$ p $ - 波幅度感兴趣，也需要考虑到$ s $ - wave $kπ$弹性散射。 $γk\ tokπ$振幅与$ k^*$共振极的分析性继续参数化，我们获得$ k^{*+} \与k^+γ$ transition formition form-form-factor，并将$ q^2 = 0 $值与从实验部分偏置宽度中提取的相应值进行比较。
We present the first calculation in lattice QCD of the process $γK \to Kπ$ in which the narrow $K^*$ vector resonance appears. Using a lattice on which the pion has a mass of 284 MeV, we determine the transition amplitude at 128 points in the $(Q^2, E_{Kπ})$ plane, and find suitable resonant scattering descriptions. We demonstrate the need to account for $S$--wave $Kπ$ elastic scattering when converting the finite-volume matrix elements computed in lattice QCD to the physically relevant infinite-volume matrix elements, even when we are primarily interested in the $P$--wave amplitude. Analytically continuing parameterizations of the $γK \to Kπ$ amplitude to the $K^*$ resonance pole, we obtain the $K^{*+} \to K^+ γ$ transition form-factor, and compare the $Q^2=0$ value to the corresponding value extracted from the experimental partial-decay width.
