| 1. |
- Boucenna, Sofiane M., et al.
(författare)
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A minimal non-supersymmetric SO(10) model with Peccei-Quinn symmetry
- 2019
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Ingår i: Physics Letters B. - : Elsevier. - 0370-2693 .- 1873-2445. ; 792, s. 251-257
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Tidskriftsartikel (refereegranskat)abstract
- We present a minimal non-supersymmetric SO(10) GUT breaking directly to the Standard Model gauge group. Precise gauge coupling unification is achieved due to the presence of two color-octet scalars, one of which is accessible to LHC searches. Proton lifetime is predicted to be below 4.5 x 10(34) years, which is within the projected five-year sensitivity of the proposed Hyper-Kamiokande experiment. We find that the Standard Model observables are reproduced to a reasonable accuracy in a numerical fit, which also predicts the unknown neutrino parameters. Finally, the two scalar representations stabilize the electroweak vacuum and the dark matter is comprised of axions.
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| 2. |
- Boucenna, Sofiane M., et al.
(författare)
-
Axion inflation, proton decay, and leptogenesis in SU (5) x U(1)(PQ)
- 2018
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Ingår i: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 97:7
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Tidskriftsartikel (refereegranskat)abstract
- We implement inflation in a nonsupersymmetric SU(5) model based on a nonminimal coupling of the axion field to gravity. The isocurvature fluctuations are adequately suppressed, axions comprise the dark matter, proton lifetime estimates are of order 8 x 10(34)-3 x 10(35) yr, and the observed baryon asymmetry arises via nonthermal leptogenesis. The presence of low-scale colored scalars ensures unification of the Standard Model gauge couplings and also helps in stabilizing the electroweak vacuum.
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| 3. |
- Boucenna, Sofiane M., et al.
(författare)
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Novel constraints on mixed dark-matter scenarios of primordial black holes and WIMPs
- 2018
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Ingår i: Journal of Cosmology and Astroparticle Physics. - : IOP PUBLISHING LTD. - 1475-7516. ; :7
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Tidskriftsartikel (refereegranskat)abstract
- We derive constraints on mixed dark-matter scenarios consisting of primordial black holes (PBHs) and weakly interacting massive particles (WIMPs). In these scenarios, we expect a density spike of the WIMPs that are gravitationally bound to the PBHs, which results in an enhanced annihilation rate and increased indirect detection prospects. We show that such scenarios provide strong constraints on the allowed fraction of PBHs that constitutes the dark matter, depending on the WIMP mass m(x) and the velocity-averaged annihilation cross-section . For the standard scenario with m(x) = 100 GeV and = 3 x 10(-26) cm(3)/s, we derive bounds that are stronger than all existing bounds for PBHs with masses 10(-12) M-circle dot less than or similar to M-BH less than or similar to 10(4) where M-circle dot, is the solar mass, and mostly so by several orders of magnitude.
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