Particle physics today faces the challenge of explaining the mystery of dark matter, the origin
of matter over anti-matter in the Universe, the origin of the neutrino masses, the apparent …

With the establishment and maturation of the experimental programs searching for new
physics with sizeable couplings at the LHC, there is an increasing interest in the broader …

The existence of nonzero neutrino masses points to the likely existence of multiple Standard
Model neutral fermions. When such states are heavy enough that they cannot be produced …

We for the first time map the range of active-sterile neutrino mixing angles in which
leptogenesis is possible in the type I seesaw model with three heavy neutrinos with …

The electron-positron stage of the Future Circular Collider, FCC-ee, is a frontier factory for
Higgs, top, electroweak, and flavour physics. It is designed to operate in a 100 km circular …

This is the Snowmass2021 Energy Frontier (EF) Beyond the Standard Model (BSM) report. It
combines the EF topical group reports of EF08 (Model-specific explorations), EF09 (More …

General relativity (GR) exists in different formulations, which are equivalent in pure gravity.
Once matter is included, however, observable predictions generically depend on the version …

The observed pattern of fermion masses and mixing is an outstanding puzzle in particle
physics, generally known as the flavor problem. Over the years, guided by precision neutrino …

A bstract Heavy neutral leptons (HNLs) are hypothetical particles, motivated in the first place
by their ability to explain neutrino oscillations. Experimental searches for HNLs are typically …

A bstract The extension of the Standard Model with two gauge-singlet Majorana fermions
can simultaneously explain two beyond-the-Standard-model phenomena: neutrino masses …