Searching for neutrino-modulino oscillations at the Forward Physics Facility

TL;DR

This paper investigates neutrino-modulino oscillations within a novel dark dimension framework, using swampland conjectures to identify potential signals at CERN's Forward Physics Facility, highlighting a model with light Dirac neutrinos and detectable modulino masses.

Contribution

It introduces a new scenario where right-handed neutrinos are bulk 5D states, leading to naturally light neutrinos and a specific realization of high-scale supersymmetry with testable modulino masses at FPF.

Findings

Potential detection of modulino with ~50 eV mass at FPF

Natural suppression of Yukawa couplings due to dark dimension

Model accommodates heavy gravitino (~250 TeV) within supersymmetry

Abstract

We make use of swampland conjectures to explore the phenomenology of neutrino-modulino mixing in regions of the parameter space that are within the sensitivity of experiments at the CERN's Forward Physics Facility (FPF). We adopt the working assumption of Dirac mass terms which couple left- and right-handed neutrinos. We further assume that the 3 right-handed neutrinos are 0-modes of bulk 5-dimensional states in the dark dimension, a novel scenario which has a compact space with characteristic length-scale in the micron range that produces a natural suppression of the 4-dimensional Yukawa couplings, yielding naturally light Dirac neutrinos. We formulate a specific realization of models with high-scale supersymmetry breaking that can host a rather heavy gravitino ($m_{3/2} \sim 250$ TeV) and a modulino with mass scale ($m_4 \sim 50$ eV) within the FPF discovery reach.