Hubble tension and cosmological imprints of gauge symmetry: as a case study

Dilip Kumar Ghosh; Purusottam Ghosh; Sk Jeesun; Rahul Srivastava

doi:10.1140/epjc/s10052-024-13220-8

2024 Impact factor 4.8

Particles and Fields

Open Access

Eur. Phys. J. C (2024) 84: 853
https://doi.org/10.1140/epjc/s10052-024-13220-8

Regular Article – Theoretical Physics

Hubble tension and cosmological imprints of $U {(1)}_{X}$ gauge symmetry: $U {(1)}_{B_{3} - 3 L_{i}}$ $U(1)_{B_3-3 L_i}$ as a case study

Dilip Kumar Ghosh¹, Purusottam Ghosh¹, Sk Jeesun¹^c and Rahul Srivastava²

¹ School of Physical Sciences, Indian Association for Cultivation of Science, 2A & 2B Raja S C Mullick Road, 700032, Kolkata, India
² Department of Physics, Indian Institute of Science Education and Research-Bhopal, Bhopal Bypass Road, Bhauri, Bhopal, India

^c skjeesun48@gmail.com

Received: 26 May 2024
Accepted: 9 August 2024
Published online: 24 August 2024

Abstract

The current upper limit on $N_{eff}$ $N_\textrm{eff}$ at the time of CMB by Planck 2018 can place stringent constraints in the parameter space of BSM paradigms where their additional interactions may affect neutrino decoupling. Motivated by this fact in this paper we explore the consequences of light gauge boson ( $Z^{'}$ $$Z'$$ ) emerging from local $U {(1)}_{X}$ $$U(1)_X$$ symmetry in $N_{eff}$ $N_\textrm{eff}$ at the time of CMB. First, we analyze the generic $U {(1)}_{X}$ models with arbitrary charge assignments for the SM fermions and show that, in the context of $N_{eff}$ $N_\textrm{eff}$ the generic $U {(1)}_{X}$ gauged models can be broadly classified into two categories, depending on the charge assignments of first generation leptons. We then perform a detailed analysis with two specific $U {(1)}_{X}$ $$U(1)_X$$ models: $U {(1)}_{B_{3} - 3 L_{e}}$ $U(1)_{B_3-3L_e}$ and $U {(1)}_{B_{3} - 3 L_{μ}}$ $U(1)_{B_3-3L_\mu }$ and explore the contribution in $N_{eff}$ $N_\textrm{eff}$ due to the presence of $Z^{'}$ $$Z'$$ realized in those models. For comparison, we also showcase the constraints from low energy experiments like: Borexino, Xenon 1T, neutrino trident, etc. We show that in a specific parameter space, particularly in the low mass region of $Z^{'}$ $$Z'$$ , the bound from $N_{eff}$ $N_\textrm{eff}$ (Planck 2018) is more stringent than the experimental constraints. Additionally, a part of the regions of the same parameter space may also relax the $H_{0}$ $$H_0$$ tension.

© The Author(s) 2024

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.