UV part of QCD and EW NLO correction (virt=QCD QED) to pp-> bb_bar W+(W+->e+ve)

Asked by Biswajit Das on 2018-10-20

I am computing QCD+EW NLO correction to pp-> b b_bar W+(W+-> e+ve). I generate process ud_bar->b b_bar e+ ve at MadGraph and compare with my(code) results. The amplitude square(1/eps piece) of most of the diagrams has good agreement with MadGraph, but I face problem with few diagrams. What I noticed that those diagram has some finite number of UV part during generation at MadGraph( generate u d~ > b~ b e+ ve [virt=QCD QED]; INFO: Contributing diagrams generated: 12 Born, 1 loops, 0 R2, 2 UV), is not matching(1/eps piece) with my code. I face problem with few triangle an bubble diagram. There is no issues with the diagram, those have '0 UV' (during generation in MadGraph). Also the separate UV nor IR(1/eps) pieces are not matching with the Madgraph. I am confused about the issue. Is MadGraph computing these diagram with CT diagram or anything else?

Please help me.


Question information

English Edit question
MadGraph5_aMC@NLO Edit question
Hua-Sheng Shao Edit question
Last query:
Last reply:

Can you help with this problem?

Provide an answer of your own, or ask Biswajit Das for more information if necessary.

To post a message you must log in.