Consider a ##j## point all massive leg one loop polygonal Feynman diagram ##P## representing some scattering process cut on a particular mass channel ##s_i##. Invoking the relevant Feynman rules and proceeding with the integration via dimensional regularisation for example gives me an expression for ##\text{Cut}_{s_i}P\left(p_1^2, \dots, p_j^2, \epsilon\right)##.(adsbygoogle = window.adsbygoogle || []).push({});

I am wondering if someone could explain why it is or is not possible to send the mass corresponding to the channel that was cut to zero if I wanted to consider a massless limit?

Many thanks!

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# Cuts of a Feynman diagram and the massless limit

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