Antiproton constraints on the GeV gamma-ray excess: a comprehensive analysis

作者：Cirelli Marco^*; Gaggero Daniele; Giesen Gaelle; Taoso Marco; Urbano Alfredo

来源：Journal of Cosmology and Astroparticle Physics, 2014, 2014(12): 045.

DOI：10.1088/1475-7516/2014/12/045

• dark matter theory
• gamma ray theory
• cosmic ray theory
• gamma ray experiments

A GeV gamma-ray excess has possibly been individuated in FERMI-LAT data from the Galactic Center and interpreted in terms of Dark Matter (DM) annihilations, either in hadronic (essentially bb) or leptonic channels. In order to test this tantalizing interpretation, we address two issues: (i) we improve the computation of secondary emission from DM (Inverse Compton and Bremsstrahlung) with respect to previous works, confirming it to be very relevant for determining the DM spectrum in the leptonic channels, so that any conclusion on the DM nature of the signal critically depends on this contribution; (ii) we consider the constraints from antiprotons on the DM hadronic channel, finding that the uncertainties on the propagation model, and in particular on the halo height, play a major role. Moreover, we discuss the role of solar modulation, taking into account possible charge dependent effects whose importance is estimated exploiting detailed numerical tools. The limits that we obtain severely constrain the DM interpretation of the excess in the hadronic channel, for standard assumptions on the Galactic propagation parameters and solar modulation. However, they considerably relax if more conservative choices are adopted.

• 出版日期2014-12
• 单位中国地震局