The default value of sm param card and pythia

Asked by andy

Hi Expert,

The default value of sm param card seems not be enough precise.
The madgraph values seems be tree-level.

1. The width default value is 6.382339e-03 and 1.4947 for Higgs and top quark,
The more precise SM vaue should be 4.07e-03 (higgs working group) and 1.32 for Higgs and top quark, especially for Higgs.

2. The quark Yukawa coupling constant seems not consider the effect of quark mass running.
The width of Higgs decay to b bbar from madraph (0.0054 ) is almost twice as large as the result of Higgs working group (0.0024).

Is it necessary to replace the default values with the more precise values?
In addition, will both width and couplings of param_card be read by pythia? Or pythia uses
its internal value neglecting the width and coupling of param_card?


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MadGraph5_aMC@NLO Edit question
FabioMaltoni Edit question
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