论文标题
独家$ b $梅森衰减的近代领导式阈值重新介绍
Next-to-Leading-logarithm threshold resummation for exclusive $B$ meson decays
论文作者
论文摘要
我们将大对数$ \ ln x $的阈值重新介绍，该分数以独家$ b $ meson衰减的分解公式出现，$ x $是旁观者动量分数，到了近代领导的（NLL）精度。结果表明，NLL的重新召集效应在终点区域中提供了$ x \ sim 0 $比领先的（LL）一个强的抑制作用，从而改善了上述过程的扰动分析。我们将$ b \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ $衰减在NLL重新调整下衰减，并发现与LL重新召集的$ 20-25 \％变化的直接CP不对称变化。我们避免反梅林转化中兰道奇异性的方式几乎不会导致理论上的不确定性。
We extend the threshold resummation of the large logarithms $\ln x$ which appear in factorization formulas for exclusive $B$ meson decays, $x$ being a spectator momentum fraction, to the next-to-leading-logarithm (NLL) accuracy. It is shown that the NLL resummation effect provides suppression in the end-point region with $x\sim 0$ stronger than the leading-logarithm (LL) one, and thus improves perturbative analyses of the above processes. We revisit the $B\to Kπ$ decays under the NLL resummation, and find that it induces 20-25\% variation of the direct CP asymmetries compared to those from the LL resummation. Our way to avoid the Landau singularity in the inverse Mellin transformation causes little theoretical uncertainty.
