Speaker:
Jan Tristram Acuña
Institution:
SISSA (Trieste, Italy)
Date:
Wednesday, November 4, 2020
Time:
11:00 am
Location:
Zoom Seminar
Abstract:
In this talk, I will explore a fairly minimal realization of a dark sector, which consists of dark fermions that are charged under an unbroken U(1) interaction mediated by the dark photon. It also involves a portal interaction between dark fermions and SM fermions, which is mediated by scalar messengers. Dark fermions in this scenario are the dark matter. Furthermore, a peculiar feature of this setup is the presence of dark and visible sector reservoirs, which do not necessarily have the same temperature. In studying the thermal history of the early Universe in this scenario, we numerically solved a set of Boltzmann equations which track not only the number density of each of the dark species, but also the entropy exchanges between the reservoirs. I will discuss the viability of this scenario by determining the couplings and masses that are consistent with the known matter relic density and the CMB constraint on extra radiation components. Finally, I will also discuss direct detection constraints on this scenario, and compare the limits with complementary constraints from the magnetic dipole moments of leptons and cooling of stellar systems.
In this talk, I will explore a fairly minimal realization of a dark sector, which consists of dark fermions that are charged under an unbroken U(1) interaction mediated by the dark photon. It also involves a portal interaction between dark fermions and SM fermions, which is mediated by scalar messengers. Dark fermions in this scenario are the dark matter. Furthermore, a peculiar feature of this setup is the presence of dark and visible sector reservoirs, which do not necessarily have the same temperature. In studying the thermal history of the early Universe in this scenario, we numerically solved a set of Boltzmann equations which track not only the number density of each of the dark species, but also the entropy exchanges between the reservoirs. I will discuss the viability of this scenario by determining the couplings and masses that are consistent with the known matter relic density and the CMB constraint on extra radiation components. Finally, I will also discuss direct detection constraints on this scenario, and compare the limits with complementary constraints from the magnetic dipole moments of leptons and cooling of stellar systems.
Host:
Mauro Valli