Lepton flavour violating slepton decays to test type-I and II seesaw at the LHC

TL;DR

This paper explores how lepton flavour violating slepton decays at the LHC can serve as indirect tests for type-I and II seesaw mechanisms, linking neutrino sector physics to observable collider signatures.

Contribution

It introduces a method using decay rate ratios to extract neutrino sector imprints and analyzes minimal supergravity parameter space for LFV decay rates within type-I and II seesaw models.

Findings

LFV decay rate ratios effectively reveal neutrino sector details.

Certain neutrino scenarios within type-I seesaw produce distinctive LFV signals.

LFV slepton decay rates can be sizable within current experimental constraints.

Abstract

Searches at the LHC of lepton flavour violation (LFV) in slepton decays can indirectly test both type-I and II seesaw mechanisms. Assuming universal flavour-blind boundary conditions, LFV in the neutrino sector is related to LFV in the slepton sector by means of the renormalization group equations. Ratios of LFV slepton decay rates result to be a very effective way to extract the imprint left by the neutrino sector. Some neutrino scenarios within the type-I seesaw mechanism are studied. Moreover, for both type-I and II seesaw mechanisms, a scan over the minimal supergravity parameter space is performed to estimate how large LFV slepton decay rates can be, while respecting current low-energy constraints.