Year: 2025
Type: article
Abstract: A bstract We investigate how extensions of the Standard Model (SM) involving heavy neutral leptons (HNLs) can be probed at FCC-ee, the proposed high-energy circular e + e − collider. Using the effective field theory (EFT) approach, we determine the impact of new interactions on the production and decay of HNLs at FCC-ee. In particular, we consider d ≤ 7 ν SMEFT operators which induce vector, scalar and tensor four-fermion and effective charged- and neutral-current interactions of HNLs, that may also mix with the active neutrinos of the SM. We consider sensitivities to the active-sterile mixing and EFT Wilson coefficients from monophoton searches and displaced vertex decay signatures. In both analyses, we consider the scenarios where HNLs are Majorana or Dirac fermions. We translate the upper bounds on the Wilson coefficients to lower limits on the scale of new physics.
Source: Journal of High Energy Physics
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: diamond
Awards: G2854926659, Hunting Invisibles: Dark sectors, Dark matter and Neutrinos, South-East Particle Theory Alliance (SEPTA), 2023-26, UCL Node, G434337789, Theoretical physics of nuclei, particles and fields, G5519330468, FLAMENCO: Flavor, Lepton number, And Mass Explorations of Neutrinos at the COmpact muon solenoid, G8145856165, G8494009122, Neutrino mass origin: from colliders to gravitational waves
OpenAlex ID: W4415719415