Testing the non-unitarity of the leptonic mixing matrix at FASER{\nu} and FASER{\nu}2

TL;DR

This paper explores how upcoming FASER{ u} and FASER{ u}2 neutrino data can be used to test the unitarity of the leptonic mixing matrix, contributing to future global analyses despite current limitations.

Contribution

It analyzes the potential of FASER{ u} and FASER{ u}2 experiments to probe non-unitarity in the neutrino mixing matrix, highlighting their role in future physics searches.

Findings

FASER{ u} and FASER{ u}2 can contribute to testing neutrino mixing unitarity.

Current constraints from these experiments are limited but valuable for future analyses.

The experiments can help improve global understanding of neutrino physics.

Abstract

The FASER{\nu} experiment has detected the first neutrino events coming from LHC. Near future high-statistic neutrino samples will allow us to search for new physics within the neutrino sector. Motivated by the forthcoming promising FASER{\nu} neutrino data, and its succesor, FASER{\nu}2, we study its potential for testing the unitarity of the neutrino lepton mixing matrix. Although it would be challenging for FASER{\nu} and FASER{\nu}2 to have strong constraints on this kind of new physics, we discuss its role in contributing to a future improved global analysis.