TY  - EJOUR
AU  - Bringmann, Torsten
AU  - Gonzalo, Tomás E.
AU  - Kahlhoefer, Felix
AU  - Matuszak, Jonas
AU  - Tasillo, Carlo
TI  - Hunting WIMPs with LISA: Correlating dark matter and gravitational wave signals
IS  - DESY-23-184
M1  - PUBDB-2023-06699
M1  - DESY-23-184
M1  - P3H-086
M1  - TTP-055
M1  - arXiv:2311.06346
PY  - 2023
N1  - 29 pages, 12 figures + appendices
AB  - The thermal freeze-out mechanism  in its classical form is tightly connected to physics beyond the Standard Model around  the electroweak scale, which has been the target of enormous experimental efforts. In  this work we study a dark matter model in which freeze-out is triggered by a strong first-order  phase transition in a dark sector, and show that this phase transition must also happen  close to the electroweak scale, i.e. in the temperature range relevant for gravitational  wave searches with the LISA mission. Specifically, we consider the spontaneous breaking  of a U(1)′ gauge symmetry through the vacuum expectation value of a scalar field,  which generates the mass of a fermionic dark matter candidate that subsequently  annihilates into dark Higgs and gauge bosons. In this set-up the peak frequency of the  gravitational wave background is tightly correlated with the dark matter relic  abundance, and imposing the observed value for the latter implies that the former must  lie in the milli-Hertz range. A peculiar feature of our set-up is that the dark sector  is not necessarily in thermal equilibrium with the Standard Model during the phase  transition, and hence the temperatures of the two sectors evolve independently.  Nevertheless, the requirement that the universe does not enter an extended period of  matter domination after the phase transition, which would strongly dilute any  gravitational wave signal, places a lower bound on the portal coupling that governs the  entropy transfer between the two sectors. As a result, the predictions for the peak  frequency of gravitational waves in the LISA band are robust, while the amplitude can  change depending on the initial dark sector temperature.
KW  - gravitational radiation, frequency (INSPIRE)
KW  - scale, electroweak interaction (INSPIRE)
KW  - symmetry, gauge (INSPIRE)
KW  - freeze-out, thermal (INSPIRE)
KW  - fermion, dark matter (INSPIRE)
KW  - dark matter, relic density (INSPIRE)
KW  - gravitational radiation, background (INSPIRE)
KW  - fermion, mass (INSPIRE)
KW  - field theory, scalar (INSPIRE)
KW  - critical phenomena (INSPIRE)
KW  - temperature (INSPIRE)
KW  - LISA (INSPIRE)
KW  - hidden sector (INSPIRE)
KW  - new physics (INSPIRE)
KW  - WIMP (INSPIRE)
KW  - U(1) (INSPIRE)
KW  - entropy (INSPIRE)
KW  - gauge boson (INSPIRE)
KW  - spontaneous symmetry breaking (INSPIRE)
LB  - PUB:(DE-HGF)25
DO  - DOI:10.3204/PUBDB-2023-06699
UR  - https://bib-pubdb1.desy.de/record/597831
ER  -