论文标题
在Sudakov的外形上，两个因素
On the Sudakov form factor, and a factor of two
论文作者
论文摘要
我回答了一个罗马·杰基（Roman Jackiw）问我的问题，我从答案中汲取了一些教训。问题是：与壳案例相比，如果用于外壳费米子，为什么Sudakov形状尺寸要大于两个因素？答案阐明了红外线和串线奇异性之间的相互作用以及两个因素的重要性。
I answer a question that Roman Jackiw asked me, and I draw some lessons from the answer. The question is: why is the Sudakov form factor larger by a factor of two, if computed for off-shell fermions, in comparison to the on-shell case? The answer sheds some light on the interplay between infrared and collinear singularities -- and the importance of factors of two.
