Interpretations of the possible 42.7 GeV $\gamma$-ray line

TL;DR

This paper explores potential models explaining a tentative 42.7 GeV gamma-ray line observed in galaxy clusters, analyzing dark matter annihilation parameters and setting upper limits on annihilation cross sections.

Contribution

It proposes several theoretical models to interpret the gamma-ray line and estimates their parameters, providing constraints on dark matter annihilation cross sections.

Findings

Possible dark matter mass around 43 GeV.

Estimated annihilation cross section needed for the signal.

Upper limits on cross sections for various final states.

Abstract

Recently Liang et al. found a tentative line signal at about 43 GeV in the directions of sixteen nearby Galaxy Clusters. If arising from dark matter annihilation, the mass of the dark matter particles should be $m_{\chi}\sim 43$ GeV and the annihilation cross section $\langle \sigma v \rangle \sim 5\times10^{-28}(\overline{\rm BF}/10^{3})^{-1}~{\rm cm^3~s^{-1}}$ is needed, where $\overline{\rm BF}$ is the averaged boost factor of the annihilation signal of these Galaxy Clusters. In this work we discuss several models which could interpret these features and estimate the model parameters. Usually sizeable coupling parameter is needed. The $2\sigma$ upper limits on the cross section of the dark matter annihilation into various final states such as $b\bar{b}$, $\mu^+\mu^-$ and so on are also presented.