Dark Matter Signals from Timing Spectra at Neutrino Experiments.

Bhaskar Dutta,Seodong Shin,Jong-Chul Park,Doojin Kim,Shu Liao,Louis E Strigari

doi:10.1103/physrevlett.124.121802

Abstract

We propose a novel strategy to search for new physics in timing spectra at low-energy neutrino experiments using a pulsed beam, envisioning the situation in which a new particle comes from the decay of its heavier partner with a finite particle width. The timing distribution of events induced by the dark matter (DM) candidate particle scattering at the detector may populate in a relatively narrow range, forming a "resonancelike" shape. Because of this structural feature, the signal may be isolated from the backgrounds, in particular when the backgrounds are uniformly distributed in energy and time. For proof of the principle, we investigate the discovery potential for DM from the decay of a dark photon in the ongoing COHERENT experiment and show the exciting prospects for exploring the associated parameter space with this experiment. We analyze the existing CsI detector data with a timing cut and an energy cut, and we find, for the first time, an excess in the timing distribution that can be explained by such DM. We compare the sensitivity to the kinetic mixing parameter (ε) for current and future COHERENT experiments with the projected limits from LDMX and DUNE.

Highlights

We propose a novel strategy to search for new physics in timing spectra at low-energy neutrino experiments using a pulsed beam, envisioning the situation in which a new particle comes from the decay of its heavier partner with a finite particle width
We analyze the existing CsI detector data with a timing cut and an energy cut, and we find, for the first time, an excess in the timing distribution that can be explained by such dark matter (DM)
In this Letter, we develop a novel strategy to search for light DM that couples with light mediators and apply it to the data from the ongoing COHERENT experiment [10]

Summary

Introduction

We propose a novel strategy to search for new physics in timing spectra at low-energy neutrino experiments using a pulsed beam, envisioning the situation in which a new particle comes from the decay of its heavier partner with a finite particle width. Dark Matter Signals from Timing Spectra at Neutrino Experiments We show how both the timing and energy data from the COHERENT experiment can be used to search for light, ≲1 GeV, DM.

Results

Conclusion