MadGraph5_aMC@NLO

Generate p p > t t~ b

Asked by Huanian Zhang

Hi Professor,

I want to generate process p p > t t~ b, but it gives the following error, how do I avoid that?

Command "generate p p > t t~ b, (t > b w+, w+ > j j), (t~ > b~ w-, w- > l- vl~)" interrupted with error:
InvalidCmd : No amplitudes generated from process Process: g/u/c/d/s/u~/c~/d~/s~ g/u/c/d/s/u~/c~/d~/s~ > t t~ b WEIGHTED=6
   Decay: t > b w+
     Decay: w+ > g/u/c/d/s/u~/c~/d~/s~ g/u/c/d/s/u~/c~/d~/s~
   Decay: t~ > b~ w-
     Decay: w- > e-/mu- ve~/vm~/vt~. Please enter a valid process

Thank you very much.

Huanian

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Huanian Zhang
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Rikkert Frederix (frederix) said : 		#1

Dear Huanian,

As the error message states, there are no valid amplitudes for your process: there no diagrams for your process. You either have to include the b quarks in the proton (i.e. a 5 flavour scheme calculation) or generate p p > t t~ b b~, where one of the b quarks is allowed to go into the beam pipe (i.e. a 4 flavour scheme calculation).

Best regards,
Rikkert

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Huanian Zhang (fantasyzhn) said : 		#2

Dear Rikkert,

 Thank you very much. I already had process p p > t t~ b b~.