MadGraph5_aMC@NLO

Program hangs with NLO thW production

Asked by Stefan von Buddenbrock

Dear MadGraph authors

We have been trying to generate pp > thW at NLO with the following:

import model loop_sm-no_b_mass
define p = 21 2 4 1 3 -2 -4 -1 -3 5 -5
define j = p
define tt = t t~
define wpm = w+ w-
generate p p > h wpm tt [QCD]

When I try run the event generation, it compiles quickly and passes all checks. However, the integration step gets stuck and never makes any progress... I tried this on 2.6.0, but I think the problem also happens on 2.5.5 and 2.6.1.

Is this kind of computation possible in aMC@NLO? It seems strange to me, since th production is relatively simple and adding another W shouldn't impact the QCD corrections too much.

Cheers
Stefan

Question information

Language:
English Edit question
Status:
Solved
For:
MadGraph5_aMC@NLO Edit question
Assignee:
marco zaro Edit question
Solved by:
Stefan von Buddenbrock
Solved:
Last query:
Last reply:
Revision history for this message
marco zaro (marco-zaro) said : 		#1

Hi Stefan,
the problem with tWh is that some resonant diagrams with a top quark appear. It has been detailed in this paper
arXiv:1607.05862
however, the part of the code where the contribution of the resonant top quark is subtracted has not been made public yet...
What do you need to do exactly?
cheers,

marco

Revision history for this message
Stefan von Buddenbrock (stefvonb) said : 		#2

Hi Marco

Thanks, the link you sent is what I need.

Cheers
Stefan