First experimental constraints on WIMP couplings in the effective field theory framework from CDEX

TL;DR

This paper reports new experimental constraints on WIMP couplings using effective field theory approaches from the CDEX experiment, improving bounds especially for low-mass WIMPs and extending limits to masses below 6 GeV/c^2.

Contribution

The study applies nonrelativistic and chiral effective field theories to set novel limits on WIMP interactions, including the first constraints on WIMP-pion coupling and low-mass WIMPs.

Findings

Set new limits on WIMP-nucleon couplings at 90% C.L.

Extended WIMP mass limits to below 6 GeV/c^2.

Improved bounds in the low WIMP mass region.

Abstract

We present weakly interacting massive particles (WIMPs) search results performed using two approaches of effective field theory from the China Dark Matter Experiment (CDEX), based on the data from both CDEX-1B and CDEX-10 stages. In the nonrelativistic effective field theory approach, both time-integrated and annual modulation analyses were used to set new limits for the coupling of WIMP-nucleon effective operators at 90% confidence level (C.L.) and improve over the current bounds in the low $m_{\chi}$ region. In the chiral effective field theory approach, data from CDEX-10 were used to set an upper limit on WIMP-pion coupling at 90% C.L. We for the first time extended the limit to the $m_{\chi}<$ 6 GeV/$c^2$ region.