Extra dimensions and Seesaw Neutrinos at the International Linear Collider

TL;DR

This paper explores how the International Linear Collider can detect extra-dimensional Kaluza-Klein neutrinos generated by the seesaw mechanism, enabling measurements of their properties and insights into neutrino mass origins.

Contribution

It demonstrates the potential of the ILC to produce and analyze Kaluza-Klein neutrinos, linking collider signals to neutrino mass generation mechanisms.

Findings

Kaluza-Klein neutrinos can be produced at the ILC via e+e- -> vN.

Masses and cross sections of KK neutrinos can be measured up to the third level.

Neutrino oscillation parameters can be inferred from flavor-dependent signals.

Abstract

We study the capability of the international linear collider (ILC) to probe extra dimensions via the seesaw mechanism. In the scenario we study, heavy Kaluza-Klein neutrinos generate tiny neutrino masses and, at the same time, have sizable couplings to the standard-model particles. Consequently, a Kaluza-Klein tower of heavy neutrinos (N) can be produced and studied at the ILC through the process: e+e- -> vN followed by N -> Wl decay. We show that the single lepton plus two-jets final states with large missing energy from this signal process will provide a good opportunity to measure the masses and cross sections of Kaluza-Klein neutrinos up to the third level. Furthermore, the neutrino oscillation parameters can be extracted from the flavor dependence of the lowest-mode signals, which give us information about the origin of low-energy neutrino masses.