On the effective theory of neutrino-electron and neutrino-quark interactions

Abstract We determine the four-fermion effective theory of neutrino interactions within the Standard Model including one-loop electroweak radiative corrections, in combination with the measured muon lifetime and precision electroweak data. Including two-loop matching and three-loop running corrections, we determine lepton coefficients accounting for all large logarithms through relative order O ( α α s ) and quark coefficients accounting for all large logarithms through O ( α ) . We present four-fermion coefficients valid in n f = 3 and n f = 4 flavor quark theories, as well as in the extreme low-energy limit. We relate the coefficients in this limit to neutrino charge radii governing matter effects via forward neutrino scattering on charged particles.