Radiative symmetry breaking, cosmic strings and observable gravity waves in 𝖴(1)𝖱 symmetric 𝖲𝖴(5) × 𝖴(1)χ
Date
2023-01-16
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Journal of Cosmology and Astroparticle Physics
Abstract
We implement shifted hybrid inflation in the framework of supersymmetric SU(5) × U(1)χ GUT model which provides a natural solution to the monopole problem appearing in the spontaneous symmetry breaking of SU(5). The U(1)χ symmetry is radiatevely broken after the end of inflation at an intermediate scale, yielding topologically stable cosmic strings. The Planck's bound on the gravitational interaction strength of these strings, characterized by GNμs are easily satisfied with the U(1)χ symmetry breaking scale which depends on the initial boundary conditions at the GUT scale. The dimension-5 proton lifetime for the decay p → K+ν̅, mediated by color-triplet Higgsinos is found to satisfy current Super-Kamiokande bounds for SUSY breaking scale MSUSY ≳ 12.5 TeV. We show that with minimal Kähler potential, the soft supersymmetry breaking terms play a vital role in bringing the scalar spectral index n_s within the Planck's latest bounds, although with small tensor modes r ≲ 2.5 × 10-6 and SU(5) gauge symmetry breaking scale in the range (2 × 1015≲ Mα ≲ 2 × 1016) GeV. By employing non-minimal terms in the Kähler potential, the tensor-to-scalar ratio approaches observable values (r ≲ 10-3) with the SU(5) symmetry breaking scale Mα ≃ 2 × 1016 GeV.
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/10.1088/1475-7516/2023/01/019. This article will be embargoed until 01/16/2023.
Keywords
Citation
Ahmed, Waqas, and Umer Zubair. “Radiative Symmetry Breaking, Cosmic Strings and Observable Gravity Waves in 𝖴(1) 𝖱 Symmetric 𝖲𝖴(5) × 𝖴(1) χ.” Journal of Cosmology and Astroparticle Physics 2023, no. 01 (2023): 019. https://doi.org/10.1088/1475-7516/2023/01/019.