Hello,
i've got a question regarding the "Head StandardMatrixElement".
I'm doing a one loop calculation and want to select the coefficients of the matrix elements in a list.
I solve the problem using the function TID and got information that formerly, using the function OneLoop, it was possible to access the coefficients by something like
var=Select[Variables[ans1],(Head[#]===StandardMatrixElement)&]
now this gives no output, though.
Could you explain what has changed in TID's output in regard to OneLoop's?
Kind regards,
Peter
PS: I'm using version 9.2 (development version) and a example code would be
$BreitMaison = True
num1 := SpinorUBar[p3, ms].GA[6].(GS[q] + mt).GA[7].PolarizationVector[p2, \[Mu]].(2*FV[q, \[Mu]] + 2*FV[p1, \[Mu]] + FV[p2, \[Mu]]).SpinorU[p1, mb] // DiracSimplify
amp1 = num1*FAD[{q, mt}, {q + p1, mh}, {q + p1 + p2, mh}]
res1 = -I/Pi\.b2*TID[amp1 , q]
var = Select[Variables[res1], (Head[#] === StandardMatrixElement) &]
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