%0 Generic %1 das2019galactic %A Das, Anirban %A Dasgupta, Basudeb %A Ray, Anupam %D 2019 %K tifr %T Galactic Positron Excess from Selectively Enhanced Dark Matter Annihilation? %U http://arxiv.org/abs/1911.03488 %X Precision measurements of the positron flux in cosmic ray have revealed an unexplained bump in the spectrum around $E300\,GeV$, not clearly attributable to known astrophysical processes. We propose annihilation of dark matter of mass $m_= 780\,GeV$ with a late-time cross section $v = 4.6310^-24\,cm^3\,s^-1$ as a possible source. The nonmonotonic dependence of the annihilation rate on dark matter velocity, owing to a selective $p$-wave Sommerfeld enhancement, allows such a large signal from the Milky Way without violating corresponding constraints from dwarf galaxies. We briefly explore other signatures of this scenario, and outline avenues to test it in future experiments.

@misc{das2019galactic, abstract = {Precision measurements of the positron flux in cosmic ray have revealed an unexplained bump in the spectrum around $E\simeq 300\,\mathrm{GeV}$, not clearly attributable to known astrophysical processes. We propose annihilation of dark matter of mass $m_\chi = 780\,\mathrm{GeV}$ with a late-time cross section $\sigma v = 4.63\times 10^{-24}\,\mathrm{cm^3\,s^{-1}}$ as a possible source. The nonmonotonic dependence of the annihilation rate on dark matter velocity, owing to a selective $p$-wave Sommerfeld enhancement, allows such a large signal from the Milky Way without violating corresponding constraints from dwarf galaxies. We briefly explore other signatures of this scenario, and outline avenues to test it in future experiments.}, added-at = {2019-11-13T06:38:16.000+0100}, author = {Das, Anirban and Dasgupta, Basudeb and Ray, Anupam}, biburl = {https://www.bibsonomy.org/bibtex/2ca0ffce8d9696becde3bf4de553aec05/citekhatri}, description = {Galactic Positron Excess from Selectively Enhanced Dark Matter Annihilation?}, interhash = {79e3276aa31870c58b38d345316d642a}, intrahash = {ca0ffce8d9696becde3bf4de553aec05}, keywords = {tifr}, note = {cite arxiv:1911.03488Comment: 13 pages, 12 figures, 2 Tables, Comments welcome}, timestamp = {2019-11-13T06:38:16.000+0100}, title = {Galactic Positron Excess from Selectively Enhanced Dark Matter Annihilation?}, url = {http://arxiv.org/abs/1911.03488}, year = 2019 }