CalcHEP

h-> g g effective coupling

Asked by ahh

Dear CH authors
According to the model sm(h-gg), ifound the coupling which is implemented into calchep = 4alpha/8pi*v(scale function).
In fact the decay width " which equale the coupling squared" is the same as that in DJuadi paper but with diffrent MH^3 in the numerator.
Could you please make that clear???
Thanks
Ahmed

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Alexander Pukhov (pukhov) said : 		#1

Evaluating matrix element one should get Mh^4 factor. See file symb1.red which you can get after "Symbolic calculation" and
writing "Reduce code".
Formula for width contains matrix element squared multiplied on Pcm/Mh^2. Pcm here equals to Mh/2. This is a way haw Mh^3 factor appears in formula for h->G,G width.

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Alexander Belyaev (alexander.belyaev) said : 		#2

Did this solve your problem?

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Alexander Belyaev (alexander.belyaev) said : 		#3

Dear Ahmed,
did this clarify your question and solved your problem?
Please, let us know.

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ahh (ahh) said : 		#4

Of it is
Thank you very much for you declaration and help