Compilation of low-energy constraints on 4-fermion operators in the SMEFT
Abstract
We compile information from low-energy observables sensitive to flavor-conserving 4-fermion operators with two or four leptons. Our analysis includes data from e+e- colliders, neutrino scattering on electron or nucleon targets, atomic parity violation, parity-violating electron scattering, and the decay of pions, neutrons, nuclei and tau leptons. We recast these data as tree-level constraints on 4-fermion operators in the Standard Model Effective Field Theory (SMEFT) where the SM Lagrangian is extended by dimension-6 operators. We allow all independent dimension-6 operators to be simultaneously present with an arbitrary flavor structure. The results are presented as a multi-dimensional likelihood function in the space of dimension-6 Wilson coefficients, which retains information about the correlations. In this form, the results can be readily used to place limits on masses and couplings in a large class of new physics theories.
Keywords
Cite
@article{arxiv.1706.03783,
title = {Compilation of low-energy constraints on 4-fermion operators in the SMEFT},
author = {Adam Falkowski and Martín González-Alonso and Kin Mimouni},
journal= {arXiv preprint arXiv:1706.03783},
year = {2017}
}
Comments
39 pages; full correlation matrix and likelihood function available in Mathematica notebook at https://www.dropbox.com/s/26nh71oebm4o12k/SMEFTlikelihood.nb?dl=0 v2: comments and references added, translation to Warsaw basis provided in notebook; v3: references added