Investigating the leptonic couplings of doubly charged scalars at the muon collider

TL;DR

This paper explores the potential of a 3 TeV muon collider to detect and analyze the lepton flavor conserving and violating couplings of doubly charged scalars, demonstrating significant sensitivity beyond current limits.

Contribution

It provides a model-independent analysis of doubly charged scalar couplings at a muon collider, including a new method to distinguish scalar types via angular distributions.

Findings

High signal significance for scalars >1 TeV with order one couplings.

Extensive reach in probing couplings beyond current experimental limits.

Proposed an angular variable to differentiate scalar exchange types.

Abstract

We study the lepton flavour conserving and violating couplings of a doubly charged scalar at a 3 TeV muon collider. Using a model independent Lagrangian, we analyse the electron electron, muon muon, and tau tau final states mediated by the doubly charged scalar to probe individual couplings to mu e, mu mu, and mu tau. We find that for a doubly charged scalar of mass greater than 1 TeV and order one couplings, we achieve high signal significance in these channels. We delineate the collider s sensitivity in the mass vs coupling plane, highlighting the extensive reach of the muon collider in probing these couplings far beyond the current experimental limits. We also propose an angular distribution variable to discriminate the exchange of a doubly charged scalar from that of a neutral scalar, which give identical signals.