Non-standard Charged Current Interactions: beta decays versus the LHC

TL;DR

This paper compares low-energy beta decay experiments and high-energy LHC data to constrain non-standard charged current interactions, highlighting the current and future sensitivities for different effective couplings.

Contribution

It provides a unified effective theory framework to compare collider and low-energy constraints on non-standard charged current interactions, emphasizing the role of neutrino chirality.

Findings

LHC bounds on right-handed neutrino couplings are stronger than beta decay constraints.

Low-energy experiments are more sensitive to axial-vector and pseudo-scalar couplings.

Future beta decay experiments will reach sensitivities comparable to LHC measurements.

Abstract

We discuss low-energy and collider constraints on the effective couplings characterizing non-standard charged current interactions. A direct comparison of low-energy and LHC probes can be performed within an effective theory framework, when the new physics mediating these interactions originates in the multi-TeV scale. We find that for the effective couplings involving right-handed neutrinos the LHC bounds from pp -> e+MET+X are at the (sub)percent level, already stronger than those from beta decays. For operators involving left-handed neutrinos, the (axial-)vector and pseudo-scalar effective couplings are best probed at low energy, while scalar and tensor couplings are currently probed at the same level by beta decays and the LHC channels pp -> e+MET+X and, by using SU(2) gauge invariance, pp -> e^+e^- +X. Future beta decay experiments at the 0.1% level or better will compete in sensitivity with higher statistics and higher energy data from the LHC.