Fits to the Fermi-LAT GeV excess with right-handed sneutrino dark matter: Implications for direct and indirect dark matter searches and the LHC

Abstract

Citation for published item:gerde£ noD hvid qF nd eir¡ oD wiguel nd olesD ndr @PHISA 9pits to the permiEve qe exess with rightEhnded sneutrino drk mtter X implitions for diret nd indiret drk mtter serhes nd the vrgF9D hysil review hFD WI @IPAF pF IPQSQHF Further information on publisher's website: Reprinted with permission from the American Physical Society: Physical Review D 91, 123530 c 2015 by the American Physical Society. Readers may view, browse, and/or download material for temporary copying purposes only, provided these uses are for noncommercial personal purposes. Except as provided by law, this material may not be further reproduced, distributed, transmitted, modied, adapted, performed, displayed, published, or sold in whole or part, without prior written permission from the American Physical Society. Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. We show that the right-handed (RH) sneutrino in the next-to-minimal supersymmetric standard model can account for the observed excess in the Fermi-LAT spectrum of gamma rays from the Galactic center, while fulfilling all the current experimental constraints from the LHC as well as from direct and indirect dark matter searches. We have explored the parameter space of this scenario, computed the gamma-ray spectrum for each phenomenologically viable solution and then performed a χ 2 fit to the excess. Unlike previous studies based on model-independent interpretations, we have taken into account the full annihilation spectrum, without assuming pure annihilation channels. Furthermore, we have incorporated limits from direct detection experiments, LHC bounds and also the constraints from Fermi-LAT on dwarf spheroidal galaxies and gamma-ray spectral lines. In addition, we have estimated the effect of the most recent Fermi-LAT reprocessed data (pass 8). In general, we obtain good fits to the Galactic center excess (GCE) when the RH sneutrino annihilates mainly into pairs of light singletlike scalar or pseudoscalar Higgs bosons that subsequently decay in flight, producing four-body final states and spectral features that improve the goodness of the fit at large energies. The best fit (χ 2 ¼ 20.8) corresponds to a RH sneutrino with a mass of 64 GeV which annihilates preferentially into a pair of light singletlike pseudoscalar Higgs bosons (with masses of order 60 GeV). Besides, we have analyzed other channels that also provide good fits to the excess. Finally, we discuss the implications for direct and indirect detection searches paying special attention to the possible appearanc...

SUSY implications from WIMP annihilation into scalars at the Galactic Center

“…Our work complements the recent analysis in Ref. [37], which performed a scan in a similar right-handed neutrino model, but for smaller values of λ.…”

“…Because scalar DM respects Bose-Einstein statistics and its annihilation is not p-wave suppressed, it is easier to find amenable regions of parameter space than for the neutralino, although direct-detection constraints are still strong. Fits to the spectrum of the GCE for annihilating sneutrino DM (including scalar annihilation channels) were examined more closely in [37]. Collider signatures of this scenario were discussed in [99].…”

Challenges in explaining the Galactic Center gamma-ray excess with millisecond pulsars

“…More specifically, this signal can be well fit by [31][32][33][34][35][36][37][38][39][40] GeV dark matter particles annihilating to bb with a cross section of σv = (1.7 − 2.3) × 10 −26 cm 3 /s (or by somewhat lighter particles annihilating to lighter quarks with a slightly lower cross section) [1]. The possibility that this signal constitutes the first detection of particle dark matter interactions has received considerable interest, and many dark matter models have been put forth as potentially viable explanations for the observed excess .…”

Models of Supersymmetry for Dark Matter

“…Actually, a purely right-handed sneutrino either in a natural way, because of its very weak couplings with the rest of the matter implying a scattering cross section too small (supressed by Y ν ), and a relic density too large. However, now, through its direct coupling to the singlet in (4), the right-handed sneutrino can be not only a thermal relic DM, but also have a large enough scattering cross section with nuclei as to be detected (see [15] and [16,17], and references therein).…”