Conveners
Theory and pheno I
- José Francisco Zurita (IFIC - Univ. of Valencia and CSIC (ES))
- James Beacham (Max Planck Society (DE))
Heavy neutral leptons (HNLs) are well-motivated candidates for physics beyond the Standard Model. These heavy right-handed neutrino states can couple to their left-handed Standard Model counterparts through various portals, the simplest of which are mass-mixing and transition magnetic moments. This talk discusses searches for HNLs in two different experimental settings. First, neutrino...
Recently, the KM3NeT collaboration announced the detection of the neutrino with the highest energy ever measured, 220 PeV. Nevertheless, the observation of this event is in 2.5-3.5σ tension with the non-observation of such events in 12 years at IceCube.
In fact, this is not the first anomalous measurement of an ultra-high-energy event. Namely, the ANITA-IV collaboration measured four 1 EeV...
Heavy Neutral Leptons (HNLs) provide a well-motivated extension of the Standard Model, offering a window into neutrino mass generation and potential new physics at the TeV scale. In this talk, we explore the phenomenology of HNLs at the LHC in the framework of $N_R$SMEFT, focusing on top-philic dimension-six operators. We identify two key HNL production channels: direct production in...
Extensions of the standard model of particle physics with Heavy Neutral Leptons (HNLs) can simultaneously generate the light neutrino masses as well as the baryon asymmetry of the Universe. In the minimal seesaw model, with only two HNLs, these particles form a pseudo-Dirac pair, degenerate in mass with nearly identical couplings to the SM leptons. The HNLs therefore follow a simple...
Type I seesaw models, which provide an explanation for the observed small neutrino masses, additionally predict the existence of heavy neutral leptons (HNLs). In collider-observable scenarios, these HNLs must form nearly mass-degenerate pseudo-Dirac pairs, as captured by symmetry-protected seesaw models. The mass splitting within these pairs induces heavy neutrino-antineutrino oscillations,...
