Constraints on General Light Mediators from PandaX-II Electron Recoil Data

Abstract

PandaX-II has analyzed their complete data set of the electron recoil energy spectrum and has confirmed the XENON1T (1-7) keV excess, although the excess was also found compatible with the total background. Treating the background as well known, in which case it provides a good fit to the observed spectrum, one can expect stronger constraints on any new physics model with this data. With this motivation, we derive constraints on the new general vector (V), axial-vector (A), scalar (S) and pseudoscalar (P) interactions if any of them contribute to the neutrino-electron elastic scattering. The derived constraints on the couplings at $90\%$ C.L., respectively, are $g_{V^{{}^{\prime }}}\lesssim 32\times 10^{-7}$ for the mediator mass $\lesssim 10$ keV, $g_{A^{{}^{\prime }}}\lesssim 34\times 10^{-7}$ for mass $\lesssim 10$ keV, $g_S\lesssim 49\times 10^{-7}$ for mass $\lesssim 20$ keV and $g_P\lesssim 67\times 10^{-7}$ for mass $\lesssim 30$ keV.

Comments: 8 pages + 4 figure + 1 table; Analysis part was improved. 2 dim exclusion plots were included. Some typos fixed. Published in PLB