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 1.6 x 10(-41)cm(2) and 9.0 x 10(-42)cm(2) (90% c.l.) for neutron-only SD and tensor coupling, respectively, for a mass M-WIMP similar to 40 GeV/c(2). The SD limits are the best currently available for M-WIMP > 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. (C) 2019 The Author(s). Published by Elsevier B.V.