Probing doubly charged scalar bosons from the doublet at future high-energy colliders

TL;DR

This paper explores the collider signatures of doubly charged scalar bosons from an isospin doublet with hypercharge 3/2 at the HL-LHC, demonstrating their potential detectability depending on their mass and decay modes.

Contribution

It provides the first detailed collider phenomenology analysis of doubly charged scalars from a hypercharge 3/2 doublet at the HL-LHC, including background reduction strategies.

Findings

Doubly charged scalars are potentially detectable at the HL-LHC.

Background suppression is effective with appropriate kinematic cuts.

Detection prospects depend on scalar mass and decay channels.

Abstract

The isospin doublet scalar field with hypercharge 3/2 is introduced in some new physics models such as tiny neutrino masses. Detecting the doubly charged scalar bosons from the doublet field can be a good probe of such models. However, their collider phenomenology has not been examined sufficiently. We investigate collider signatures of the doubly and singly charged scalar bosons at the LHC for the high-luminosity upgraded option (HL-LHC) by looking at transverse mass distributions etc. With the appropriate kinematical cuts we demonstrate the background reduction in the minimal model in the following two cases depending on the mass of the scalar bosons. (1) The main decay mode of the singly charged scalar bosons is the tau lepton and missing (as well as charm and strange quarks). (2) That is into a top bottom pair. In the both cases, we assume that the doubly charged scalar boson is heavier than the singly charged ones. We conclude that the scalar doublet field with $Y = 3/2$ is expected to be detectable at the HL-LHC unless the mass is too large.