分类: 物理学 >> 基本粒子与场物理学 提交时间: 2017-08-03
摘要: : We perform a detailed semi-analytical analysis of the electroweak phase transition (EWPT) property in NMSSM, which serves as a good benchmark model in which the 126 GeV Higgs mixes with a singlet. In this case, a strongly first order electroweak phase transition (SFOEWPT) is achieved by the tree-level effects and the phase transition strength γc is determined by the vacua energy gap at T = 0. We make an anatomy of the energy gap at both tree-level and loop-level and extract out a dimensionless phase transition parameter Rκ ≡ 4κvs/Aκ, which can replace Aκ in the parameterization and affect the light CP odd and even Higgs spectra. We find that SFOEWPT only occurs in Rκ ∼ −1 and positive Rκ . O(10), which in the non-PQ limit case would prefer either a relatively light CP odd or CP even Higgs boson ∼ (60, 100) GeV, therefore serves as a smoking gun signal and requires new search strategies at the LHC.
分类: 物理学 >> 基本粒子与场物理学 提交时间: 2017-08-03
摘要: The gamma-ray excess observed by the Fermi-LAT in the Galactic Center can be interpreted by the dark matter annihilation to b ¯b via a light pseudoscalar in the 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 DM particles occurring close to the light pseudoscalar resonance is favored by the galactic center excess and the observed DM relic density, and a resulting small κ/λ and a negative Aκ can also lead to a successful strongly first order electroweak phase transition
分类: 物理学 >> 核物理学 提交时间: 2016-09-13
摘要: The gamma-ray excess observed by the Fermi-LAT in the Galactic Center can be interpreted by the dark matter annihilation to bb¯ via a light pseudoscalar in the 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 DM particles occurring close to the light pseudoscalar resonance is favored by the galactic center excess and the observed DM relic density, and a resulting small κ/λ and a negative Aκ can also lead to a successful strongly first order electroweak phase transition.