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

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 $\rm 1.6 \times 10^{-41} cm^2$and$\rm 9.0 \times 10^{-42} cm^2$($90%$ c.l.) for neutron-only SD and tensor coupling, respectively, for a mass $M_$\mathrm{W}\mathrm{I}\mathrm{M}\mathrm{P}$ \sim {\rm 40~GeV}/c^2$\mathrm{.}TheSDlimitsarethebestcurrentlyavailablefor$M_$\mathrm{W}\mathrm{I}\mathrm{M}\mathrm{P}$ > {\rm 40~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.