论文标题
一环相同的螺旋度四点振幅
One-loop same helicity four-point amplitude from shifts
论文作者
论文摘要
很久以前，W。Bardeen提出了一环相同的螺旋性YM振幅的非变化，特别是在四个点上的幅度，应解释为一种异常。但是，这些振幅的可用推导远非支持这种解释，因为它们与标准三角图手性异常计算没有任何相似性。我们通过一种旨在模仿手性异常衍生的方法来提供相同的螺旋度四点振幅的新计算。这是通过使用动量保护来重写对数不同的四点振幅作为线性的总和，然后进行四次发散积分来完成的。然后看到这些积分在循环动量集成变量的适当移动后消失。因此，幅度与变化有关，这些幅度是以标准教科书方式计算的。因此，我们重现了通常的结果，但是通过一种方法可以大大加强对这些振幅的异常解释的案例。
It has been suggested a long time ago by W. Bardeen that non-vanishing of the one-loop same helicity YM amplitudes, in particular such an amplitude at four points, should be interpreted as an anomaly. However, the available derivations of these amplitudes are rather far from supporting this interpretation in that they share no similarity whatsoever with the standard triangle diagram chiral anomaly calculation. We provide a new computation of the same helicity four-point amplitude by a method designed to mimic the chiral anomaly derivation. This is done by using the momentum conservation to rewrite the logarithmically divergent four-point amplitude as a sum of linearly and then quadratically divergent integrals. These integrals are then seen to vanish after appropriate shifts of the loop momentum integration variable. The amplitude thus gets related to shifts, and these are computed in the standard textbook way. We thus reproduce the usual result but by a method which greatly strengthens the case for an anomaly interpretation of these amplitudes.
