PandaX-II Constraints on Spin-Dependent WIMP-Nucleon Effective Interactions

Abstract

We present PandaX-II constraints on candidate WIMP-nucleon effective interactions involving the nucleon or WIMP spin, including, in addition to standard axial spin-dependent (SD) scattering, various couplings among vector and axial currents, magnetic and electric dipole moments, and tensor interactions. The data set corresponding to a total exposure of 54-ton-days is reanalyzed to determine constraints as a function of the WIMP mass and isospin coupling. We obtain WIMP-nucleon cross section bounds of $1.6\times 10^{-41}\mathrm{c}{\mathrm{m}}^2$ and $9.0\times 10^{-42}\mathrm{c}{\mathrm{m}}^2$ ($90\%$ c.l.) for neutron-only SD and tensor coupling, respectively, for a mass $M_{\mathrm{WIMP}}\sim 40\mathrm{GeV}/c^2$. The SD limits are the best currently available for $M_{\mathrm{WIMP}}>40\mathrm{GeV}/c^2$. We show that PandaX-II has reached a sensitivity sufficient to probe a variety of other candidate spin-dependent interactions at the weak scale.

6 pages, 4 figures