# Factorization scale

Hi calcHEP authors,

I was told that by default MadGraph uses sqrt(M^2+pT^2) as the factorization scale where the mass and pt belong to a resonance in the s channel, I suppose. I am not sure how to include this number in the batch file, I tried

alpha Q : sqrt(M12^2+Pt12^2)

but it does not recognize Pt12^2. Is there a way to include this number? The final cross section seems to be very sensitive to this number and I cant get MadGraph to agree with calcHEP.

By the way, I was also told that this number should be the mass of the resonance M12, so I am planning to use that number for my final cross sections, and I dont understand why madgraph does the other thing.

Thanks.

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