vsht
commented
7 years ago Hi,
first of all, what are PR and PL? Are they the standard chiral projectors? Then you should use GA[6] and GA[7]. If you want to leave them arbitrary, they should be declared as non-commutative objects first:
DeclareNonCommutative[PR, PL];Second, if the calculation is meant to be done entirely in D-dimensions, use the proper input. Third, do not do D->4. Your output contains UV divergent 1-point functions and the 1/Epsilon poles will mix with Epsilon in every factor of D. By setting D to 4 you are loosing finite parts of the result.
num = Spinor[ps].GAD[mu].GSD[k].PR.Spinor[pb] Spinor[p1].GSD[k].GAD[
mu].PL.Spinor[p2]
num*FAD[{k, mt}, k, {k, mhP}, {k, mW}] // ChangeDimension[#, D] &
res=Simplify[OneLoop[k, %]]Finally, can you provide your output, where the order of spinors is changed? For me the order remains as in the original expression.
Last but not least: OneLoop is actually more or less a legacy function that I would not recommend using on new projects. In most cases it can be replaced by TID:
DeclareNonCommutative[PR, PL];
exp = Spinor[ps].GAD[mu].GSD[k].PR.Spinor[pb] Spinor[p1].GSD[k].GAD[
mu].PL.Spinor[p2] FAD[{k, mt}, k, {k, mhP}, {k, mW}] //
ChangeDimension[#, D] &;
TID[exp, k] // ToPaVe[#, k] &which gives a nice and simple result
(I \[Pi]^2 A0[
mhP^2] Spinor[Momentum[p1, D], 0, 1].GAD[$AL$2595[2]].GAD[
mu].PL.Spinor[Momentum[p2, D], 0, 1] Spinor[Momentum[ps, D], 0,
1].GAD[mu].GAD[$AL$2595[2]].PR.Spinor[Momentum[pb, D], 0,
1])/(D (mhP - mt) (mhP + mt) (mhP - mW) (mhP +
mW)) - (I \[Pi]^2 A0[
mt^2] Spinor[Momentum[p1, D], 0, 1].GAD[$AL$2596[2]].GAD[
mu].PL.Spinor[Momentum[p2, D], 0, 1] Spinor[Momentum[ps, D], 0,
1].GAD[mu].GAD[$AL$2596[2]].PR.Spinor[Momentum[pb, D], 0,
1])/(D (mhP - mt) (mhP + mt) (mt - mW) (mt +
mW)) - (I \[Pi]^2 A0[
mW^2] Spinor[Momentum[p1, D], 0, 1].GAD[$AL$2597[2]].GAD[
mu].PL.Spinor[Momentum[p2, D], 0, 1] Spinor[Momentum[ps, D], 0,
1].GAD[mu].GAD[$AL$2597[2]].PR.Spinor[Momentum[pb, D], 0,
1])/(D (mhP - mW) (mhP + mW) (-mt + mW) (mt + mW))Cheers, Vladyslav
mescia
olcyr
Hi,
I'm performing the following computation with FeynCalc 9.0.1
For some strange reason, Feyncalc changes the order of the spinors from (s)(b)(1)(2) to (s)(1)(b)(2) -- which is not manifestly Lorentz invariant. How can I prevent this type of behavior?
Many thanks in advance. O.