Shedding new light on sterile neutrinos from XENON1T experiment

Abstract

The XENON1T collaboration recently reported the excess of events from recoil electrons, possibly giving an insight into new area beyond the Standard Model (SM) of particle physics. We try to explain this excess by considering effective interactions between the sterile neutrinos and the SM particles. In this paper, we present an effective model based on one-particle-irreducible interaction vertices at low energies that are induced from the SM gauge symmetric four-fermion operators at high energies. The effective interaction strength is constrained by the SM precision measurements, astrophysical and cosmological observations. We introduce a novel effective electromagnetic interaction between sterile neutrinos and SM neutrinos, which can successfully explain the XENON1T event rate through inelastic scattering of the sterile neutrino dark matter from Xenon electrons. We find that sterile neutrinos with masses around 90 keV and specific effective coupling can fit well with the XENON1T data where the best fit points preserving DM constraints and possibly describe the anomalies in other experiments.

Constraints on general neutrino interactions with exotic fermion from neutrino-electron scattering experiments

“…Some studies instead proposed to explain the XENON1T excess through the electron recoil by solar neutrinos with the sterile neutrino DM in the final states of inelastic scattering [10,11]. On the other hand, the inverse process in which the incoming fermionic DM is absorbed by bound electron targets and emits a neutrino is sensitive to the DM with mass below MeV [12,13]. The two kinds of signals are governed by the same interactions between SM neutrino and the exotic fermion.…”

“…[2][3][4][5][6][7][8][9]. There are also plenty of novel models and signatures proposed to search for sub-GeV DM through the scattering off electrons [10][11][12][13][14][15].…”

Dark magnetic dipole property in fermionic absorption by nucleus and electrons

“…In fact, the inverse process, i.e. the conversion from neutrino to an exotic fermion [13][14][15][16][17], has been utilized to explain the recent XENON1T excess [18]. It turns out that the neutrino magnetic dipole portal can account for the excess of keV electron recoil events because the induced event rate is inversely proportional to the recoil energy [14,[19][20][21][22].…”

Xenon-1T excess as a possible signal of a sub-GeV hidden sector dark matter

“…The experiment currently can neither confirm nor exclude such a possibility. Since the publication of the Xenon-1T results, a variety of models have been proposed which include light sterile neutrinos [6][7][8][9], a goldstino [10], an inflaton [11], string-motivated models [12,13], boosted dark matter [14][15][16], and a variety of other models .…”