Sneutrino NLSP Scenarios in the NUHM with Gravitino Dark Matter

TL;DR

This paper explores sneutrino NLSP scenarios within the NUHM framework, analyzing their theoretical basis, constraints, collider signatures, and how they differ from neutralino LSP models.

Contribution

It demonstrates that sneutrino NLSP scenarios are generic in NUHM models and provides a comprehensive analysis of their phenomenology and constraints.

Findings

Sneutrino NLSP scenarios are possible in NUHM models.

Distinct collider signatures differentiate sneutrino NLSP from neutralino LSP.

Constraints from cosmology and experiments limit the parameter space.

Abstract

We analyze scenarios in which some flavour of sneutrino is the next-to-lightest supersymmetric particle (NLSP), assuming that the gravitino is the lightest supersymmetric particle (LSP) and provides the cold dark matter. Such scenarios do not arise in the constrained supersymmetric extension of the Standard Model (CMSSM) with universal gaugino and scalar masses input at the GUT scale. However, models with non-universal Higgs masses (NUHM) do allow scenarios with a sneutrino NLSP, which are quite generic. We illustrate how such scenarios may arise, analyze the possible metastable sneutrino lifetime, and explore the theoretical, phenomenological, experimental and cosmological constraints on such scenarios. We also discuss the collider signatures of such scenarios, how they may be distinguished from neutralino LSP scenarios, and how different flavours of sneutrino NLSP may be distinguished.