Gamma rays from bino-like dark matter in the MSSM

Abstract

We consider regions of the parameter space of the Minimal Supersymmetric Standard Model (MSSM) with bino-like neutralino dark matter in which a large fraction of the total dark matter annihilation cross section in the present era arises from annihilation to final states with monoenergetic photons. The region of interest is characterized by light sleptons and heavy squarks. We find that it is possible for the branching fraction to final states with monoenergetic photons to be comparable to that for continuum photons, but in those cases the total cross section will be so small that it is unlikely to be observable. For models where dark matter annihilation may be observable in the present era, the branching fraction to final states with monoenergetic photons is O(1 − 10%).

Internal Bremsstrahlung Signature of Real Scalar Dark Matter and Consistency with Thermal Relic Density

“…Many authors have provided models of this excess by monochromatic gamma rays from DM annihilation or decay; see, for example, Refs. [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23]. If the source of the gamma-ray excess is DM annihilation, the required cross section into two photons is v ¼ 1:27 Â 10 À27 cm 3 =s for an Einasto DM density distribution; this value can change for a different DM profile [2].…”

Naturalness of light neutralino dark matter in pMSSM after LHC, XENON100 and Planck data

“…It is clear from figure 5 that the current sensitivity of Fermi-LAT [142] still leaves all of our allowed parameter space untouched. The future data from ongoing Fermi-LAT and next generation gamma-ray searches might be able to probe our allowed parameter space with a photon line signal [152]. For completeness, we also show in figure 6 some other relevant pMSSM parameters with respect to the lightest neutralino mass.…”

Electroweak bremsstrahlung in binolike dark matter annihilations

“…In recent years, the significance of electroweak bremsstrahlung emitting W=Z bosons has been recognized in the literature [10][11][12][13][14][15][16][17][18][19][20][21][22]. In particular, the weak bremsstrahlung is expected to be more important in evaluating neutrino flux than the usual bremsstrahlung emitting photons, since the former emits primary neutrinos.…”

“…For a winolike dark matter, initial-state W=Z radiations were found to be important [16]. Gamma rays from binolike dark matter annihilations in the MSSM were examined including the three-body final state with weak bremsstrahlung [17]. Neutrino signals from weak bremsstrahlung in the MSSM were studied for a binolike TeV dark matter scenario [18].…”