2021/09/30 by Debasish Borah, Arnab Dasgupta, Sin Kyu Kang
Physics and Astronomy · #Astrophysics #Black Holes and Theoretical Physics #Condensed matter physics #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #Dark matter #Order (exchange) #Phase (matter) #Phase transition #Physics #Quantum mechanics #astro-ph.CO #hep-ph
paper · pdf · doi:10.1088/1475-7516/2021/12/039
10 pages, 6 captioned figures. accepted for publication in JCAP. arXiv admin note: substantial text overlap with arXiv:2105.01007
openalex created_date 2021/10/11 · openalex publication_date 2021/12/01 · arxiv created 2021/12/12 · arxiv updated 2022/01/05 · openalex updated_date 2026/08/05
Abstract We study a dark SU(2) D gauge extension of the standard model (SM) with the possibility of a strong first order phase transition (FOPT) taking place below the electroweak scale in the light of NANOGrav 12.5 yr data. As pointed out recently by the NANOGrav collaboration, gravitational waves (GW) from such a FOPT with appropriate strength and nucleation temperature can explain their 12.5 yr data. We impose a classical conformal invariance on the scalar potential of SU(2) D sector involving only a complex scalar doublet with negligible couplings with the SM Higgs. While a FOPT at sub-GeV temperatures can give rise to stochastic GW around nano-Hz frequencies being in agreement with NANOGrav findings, the SU(2) D vector bosons which acquire masses as a result of the FOPT in dark sector, can also serve as dark matter (DM) in the universe. The relic abundance of such vector DM can be generated in a non-thermal manner from the SM bath via scalar portal mixing. We also discuss future sensitivity of gravitational wave experiments to the model parameter space.