Cosmological constraints on the seesaw scale

  • Dipartimento di Fisica - Aula 500
  • Seminario

Relatori

Jacobo Lopez Pavon
SISSA

Dettagli

I will study the simplest extension of the SM that can account for neutrino masses, the Type-I seesaw with 2 right-handed neutrinos, and the next-to-minimal scenario, with 3 right-handed neutrinos. The model introduces a New Physics scale, M, which is often assumed to be much larger than the electroweak scale. However, it is presently unconstrained and the light neutrino masses and mixing can be generated for any value of M above eV. Its determination is thus a very important open question in neutrino physics. Paying special attention to the contribution of the sterile states to $N_{eff}$ as a function of M, I will show that a large part of the M parameter space can be excluded thanks to cosmological measurements. The implications for neutrinoless double beta decay will also be discussed.