%0 Generic %1 bernal2022seeking %A Bernal, José Luis %A Caputo, Andrea %A Sato-Polito, Gabriela %A Mirocha, Jordan %A Kamionkowski, Marc %D 2022 %K tifr %T Seeking dark matter with $\gamma$-ray attenuation %U http://arxiv.org/abs/2208.13794 %X The flux of high-energy astrophysical $\gamma$ rays is attenuated by the production of electron-positron pairs from scattering off of extragalactic background light (EBL). We use the most up-to-date information on galaxy populations to compute their contributions to the pair-production optical depth. We find that the optical depth inferred from $\gamma$-ray measurements exceeds that expected from galaxies at the $\sim2\sigma$ level. If the excess is modeled as a frequency-independent re-scaling of the standard contribution to the EBL from galaxies, then it is detected at the $2.7\sigma$ level (an overall $14-30\%$ increase of the EBL). If the frequency dependence of the excess is instead modeled as a two-photon decay of a dark-matter axion, then the excess is favored over the null hypothesis of no excess at the $2.1\sigma$ confidence level. While we find no evidence for a dark-matter signal, the analysis sets the strongest current bounds on the photon-axion coupling over the $8-25$ eV mass range.

@misc{bernal2022seeking, abstract = {The flux of high-energy astrophysical $\gamma$ rays is attenuated by the production of electron-positron pairs from scattering off of extragalactic background light (EBL). We use the most up-to-date information on galaxy populations to compute their contributions to the pair-production optical depth. We find that the optical depth inferred from $\gamma$-ray measurements exceeds that expected from galaxies at the $\sim2\sigma$ level. If the excess is modeled as a frequency-independent re-scaling of the standard contribution to the EBL from galaxies, then it is detected at the $2.7\sigma$ level (an overall $14-30\%$ increase of the EBL). If the frequency dependence of the excess is instead modeled as a two-photon decay of a dark-matter axion, then the excess is favored over the null hypothesis of no excess at the $2.1\sigma$ confidence level. While we find no evidence for a dark-matter signal, the analysis sets the strongest current bounds on the photon-axion coupling over the $8-25$ eV mass range.}, added-at = {2022-08-31T09:53:52.000+0200}, author = {Bernal, José Luis and Caputo, Andrea and Sato-Polito, Gabriela and Mirocha, Jordan and Kamionkowski, Marc}, biburl = {https://www.bibsonomy.org/bibtex/2a2b02c2e0b2fe43816b6ba2126198adb/citekhatri}, description = {Seeking dark matter with $\gamma$-ray attenuation}, interhash = {057367515c002a9e63c1c66ad5217edc}, intrahash = {a2b02c2e0b2fe43816b6ba2126198adb}, keywords = {tifr}, note = {cite arxiv:2208.13794Comment: 5 pages (+4 pages of references), 3 figures. 3 pages and 3 figures of supplementary material}, timestamp = {2022-08-31T09:53:52.000+0200}, title = {Seeking dark matter with $\gamma$-ray attenuation}, url = {http://arxiv.org/abs/2208.13794}, year = 2022 }