Detecting electron neutrinos from solar dark matter annihilation by JUNO

Wan-Lei Guo

doi:10.1088/1475-7516/2016/01/039

Abstract

We explore the electron neutrino signals from light dark matter (DM) annihilation in the Sun for the large liquid scintillator detector JUNO. In terms of the spectrum features of three typical DM annihilation channels χχ → νν̄, τ+τ−, bb̄, we take two sets of selection conditions to calculate the expected signals and atmospheric neutrino backgrounds based on the Monte Carlo simulation data. Then the JUNO sensitivities to the spin independent DM-nucleon and spin dependent DM-proton cross sections are presented. It is found that the JUNO projected sensitivities are much better than the current spin dependent direct detection experimental limits for the νν̄ and τ+τ− channels. In the spin independent case, the JUNO will give the better sensitivity to the DM-nucleon cross section than the LUX and CDMSlite limits for the νν̄ channel with the DM mass lighter than 6.5 GeV . If the νν̄ or τ+τ− channel is dominant, the future JUNO results are very helpful for us to understand the tension between the DAMA annual modulation signal and other direct detection exclusions.

Highlights

The existence of dark matter (DM) is well confirmed [1, 2]
As well as in the DM direct detection experiments, the halo DM particles can elastically scatter with nuclei in the Sun
For the νe/νe signals from the DM annihilation in the Sun, the related backgrounds are due to the atmospheric neutrino charged current (CC) and neutral current (NC) interactions in the Jiangmen Underground Neutrino Observatory (JUNO)

Summary

INTRODUCTION

The existence of dark matter (DM) is well confirmed [1, 2]. The current cosmological observations have helped to establish the concordance cosmological model where the present Universe consists of about 69.3% dark energy, 25.8% dark matter and 4.9% atoms [3]. We focus on the neutrino signals from the DM annihilation in the Sun. As well as in the DM direct detection experiments, the halo DM particles can elastically scatter with nuclei in the Sun. As well as in the DM direct detection experiments, the halo DM particles can elastically scatter with nuclei in the Sun They may lose most of their energy and are captured in the Sun [1]. The JUNO LS detector can detect the neutrinos from the DM annihilation in the Sun. In Ref. [7], the JUNO has calculated the νμ/νμ signals from the DM annihilation in the Sun. Some authors have analyzed the νe/νe and νμ/νμ signals for the other LS detectors [10].

NEUTRINOS FROM THE DM ANNIHILATION IN THE SUN

ELECTRON NEUTRINOS AND ANTINEUTRINOS IN JUNO

SENSITIVITIES TO THE DM DIRECT DETECTION CROSS SECTIONS

Findings

CONCLUSIONS