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1. chinaXiv:201607.00019 [pdf]

Neutrino constraints on inelastic dark matter after CDMS II results

Shu, Jing; Yin, Peng-fei; Zhu, Shou-hua
Subjects: Physics >> The Physics of Elementary Particles and Fields

We discuss the neutrino constraints from solar and terrestrial dark matter (DM) annihilations in the inelastic dark matter (iDM) scenario after the recent CDMS II results. To reconcile the DAMA/LIBRA data with constraints from all other direct experiments, the iDM needs to be light (m(chi) < 100 GeV) and have a large DM-nucleon cross section (sigma(n) similar to 10(-4) pb in the spin-independent (SI) scattering and sigma(n) similar to 10 pb in the spin-dependent (SD) scattering). The dominant contribution to the iDM capture in the Sun is from scattering off Fe/Al in the SI/SD case. Current bounds from Super-Kamiokande exclude the hard DM annihilation channels, such as W+W-, ZZ, t<(t)over bar>, and tau(+)tau(-). For soft channels such as b (b) over bar and c (c) over bar, the limits are loose, but could be tested or further constrained by future IceCube plus DeepCore. For neutrino constraints from the DM annihilation in the Earth, due to the weaker gravitational effect of the Earth and inelastic capture condition, the constraint exists only for small mass splitting delta < 40 keV and m(chi) similar to (10, 50) GeV even in the tau(+)tau(-) channel.

submitted time 2016-07-05 Hits2516Downloads479 Comment 0

2. chinaXiv:201606.00312 [pdf]

Interpretation of the Galactic Center excess and electroweak phase transition in the NMSSM

Bi, Xiao-Jun; Bian, Ligong; Huang, Weicong; Shu, Jing; Yin, Peng-Fei
Subjects: Physics >> The Physics of Elementary Particles and Fields

The gamma-ray excess observed by the Fermi-LAT in the Galactic Center can be interpreted by the dark matter annihilation to b (b) over bar via a light pseudoscalar in the next-to-minimal supersymmetric standard model (NMSSM). It is interesting to note that the corresponding singlet scalar is useful to achieve a strongly first-order phase transition required by the electroweak baryogenesis. In this paper, we investigate the possibility that the NMSSM model can simultaneously accommodate these two issues. The phase transition strength can be characterized by the vacua energy gap at zero temperature and be sufficiently enhanced by the tree-level effect in the NMSSM. We find that the annihilation of singlino/Higgsino dark matter (DM) particles occurring close to the light pseudoscalar resonance is favored by the Galactic Center excess and the observed DM relic density, and some resulting regions in the parameter space with a small kappa/lambda. and a negative A. can simultaneously account for a successful strongly first-order electroweak phase transition.

submitted time 2016-06-24 Hits2599Downloads787 Comment 0

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