Hi Florian,

When I'm generating Observable_PengV2d2L.pdf in SARAH/Output/SM/EWSB/TeX/FlavorKit/Peng2d2l, i can't find the photon contribution, while i find only the Z boson which couples to l\bar{l} ..

Also I found Wilson Coeff PVOddllVRR, PVOddllVRL, and PVOddllVLR, shouldn't they vanish in SM ? since we have only left-handed femions .


Thanks.

- As explained in https://arxiv.org/abs/1405.1434, the monopole and dipole operators are handled separately.
- SARAH generates all possible diagrams brute-force. It doesn't check which vanish.

Cheers,
Florian

PS: Please stop generating several times a new thread for the same topic.

Oh sorry I deleted the old post and made another one.

SARAH generates all possible diagrams brute-force. It doesn't check which vanish

So that means we can get in SM a Wilson coeff. for an operator like: OddllVRR which equals (l \gamma_\mu P_R l ) (d \gamma_\mu P_R d ) ,
although there is no couplings for right handed fermions i,e, like \Gamma^{ee Z, R} or \Gamma^{uu Z, R} ? doesn’t SARAH take these couplings equal zero in SM ?


Best.

No, SARAH just expresses the operator in terms of generic couplings. Afterwards, if it plugs in the correct vertices for a given model, it might be that some operators vanish of the couplings vanish.

Cheers,
Florian