Smooth hybrid inflation with low reheat temperature and observable gravity waves in SU(5) × U(1)χ super-GUT
Date
2022-06-23
Journal Title
Journal ISSN
Volume Title
Publisher
Journal of Cosmology and Astroparticle Physics
Abstract
We realize smooth hybrid inflation in the framework of supersymmetric SU(5) × U(1)χ ⊂ SO(10) model which provides a natural solution to the monopole problem appearing in the spontaneous symmetry breaking of SU(5). The breaking of U(1)χ symmetry leaves a residual discrete Z2 symmetry, that serves as the MSSM matter parity, realizing the possibility of the lightest supersymmetric particle as a cold dark matter candidate. The d = 5 proton lifetime for the decay p ⟶ K+ν̅, mediated by color-triplet Higgsinos is found to satisfy current experimental bounds if split-high scale SUSY scenario is employed. We show that with minimal Kähler potential, the soft supersymmetry breaking terms play a vital rôle in bringing the scalar spectral index ns within the Planck's latest bounds. In a minimal Kähler potential setup, small values of tensor-to-scalar ratio r ≲ 3.5 × 10-7 are obtained, whereas the gravitino mass turns out to be in the range that favors PeV scale SUSY but is not sufficiently high to avoid the d = 5 proton decay. A non-minimal Kähler potential including higher order corrections is required to realize successful inflation with central value of scalar spectral index ns = 0.9655, large tensor modes r ≲ 0.056 and a low reheat temperature (3 × 106 ≲ Tr ≲ 6.5 × 107) GeV consistent with leptogenesis and baryogenesis.
Description
This is the Accepted Manuscript version of an article accepted for publication in
Journal of Cosmology and Astroparticle Physics. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at https://doi.org/10.1088/1475-7516/2022/06/027. This article will be embargoed until 06/23/2023.
Keywords
inflation, supersymmetry and cosmology, baryon asymmetry, big bang nucleosynthesis
Citation
Ahmed, Waqas, Athanasios Karozas, George K. Leontaris, and Umer Zubair. “Smooth Hybrid Inflation with Low Reheat Temperature and Observable Gravity Waves in SU(5) × U(1)χ Super-GUT.” Journal of Cosmology and Astroparticle Physics 2022, no. 06 (June 1, 2022): 027. https://doi.org/10.1088/1475-7516/2022/06/027.