LHC Phenomenology of the Type II Seesaw Mechanism: Observability of Neutral Scalars in the Nondegenerate Case

TL;DR

This paper investigates the potential to observe neutral scalars in the type II seesaw model at the LHC, focusing on the nondegenerate mass scenario and analyzing specific decay channels with detailed simulations.

Contribution

It provides a detailed analysis of neutral scalar production in the nondegenerate case, highlighting the enhanced observability via cascade decays at the LHC.

Findings

Mass reach of 151-180 GeV in various channels at 14 TeV LHC with 3000/fb.

Cascade decays extend the mass reach beyond pure Drell-Yan production.

Neutral scalars are accessible at LHC run II in the negative scenario.

Abstract

This is a sequel to our previous work on LHC phenomenology of the type II seesaw model in the nondegenerate case. In this work, we further study the pair and associated production of the neutral scalars H^0/A^0. We restrict ourselves to the so-called negative scenario characterized by the mass order M_{H^{\pm\pm}}>M_{H^\pm}>M_{H^0/A^0}, in which the H^0/A^0 production receives significant enhancement from cascade decays of the charged scalars H^{\pm\pm},~H^\pm. We consider three important signal channels---b\bar{b}\gamma\gamma, b\bar{b}\tau^+\tau^-, $b\bar{b}\ell^+\ell^-\cancel{E}_T$---and perform detailed simulations. We find that at the 14 TeV LHC with an integrated luminosity of 3000/fb, a 5\sigma mass reach of 151, 150, and 180 GeV, respectively, is possible in the three channels from the pure Drell-Yan H^0A^0 production, while the cascade-decay-enhanced H^0/A^0 production can push the mass limit further to 164, 177, and 200 GeV. The neutral scalars in the negative scenario are thus accessible at LHC run II.