Chiral power counting of one- and two-body currents in direct detection of dark matter

TL;DR

This paper develops a unified chiral power-counting framework for various WIMP-nucleon interactions, deriving relevant currents and revealing a hierarchy among operators, with implications for dark matter direct detection experiments.

Contribution

It introduces a comprehensive chiral power-counting scheme for WIMP-nucleon interactions, including all relevant currents up to third order, and identifies new interaction channels involving two-body currents.

Findings

Chiral symmetry predicts a hierarchy among non-relativistic operators.

Two-body currents become relevant in certain interaction channels.

Derived all one- and two-body currents up to third order in the chiral expansion.

Abstract

We present a common chiral power-counting scheme for vector, axial-vector, scalar, and pseudoscalar WIMP-nucleon interactions, and derive all one- and two-body currents up to third order in the chiral expansion. Matching our amplitudes to non-relativistic effective field theory, we find that chiral symmetry predicts a hierarchy amongst the non-relativistic operators. Moreover, we identify interaction channels where two-body currents that so far have not been accounted for become relevant.