Add additional EW_SCHEME options for DY
... in particular to allow specifying sinThetaW and mZ simultaneously at the expense of mW, similar to what is available on master (cf. 4e6565e1).
Three sub-options for specifying the QED coupling are introduced:
-
EW_SCHEME=20
for alpha(0), mZ, sinThetaW -
EW_SCHEME=21
for Gmu, mZ, sinThetaW -
EW_SCHEME=22
for alpha(mZ), mZ, sinThetaW
Note: The numbering is different from master but consistent with OpenLoops for now, and should be unified between OpenLoops and master for the future using strings instead of numbers.