Natural Baryogenesis from Unnatural Supersymmetry

TL;DR

This paper proposes a novel baryogenesis mechanism within mini-split supersymmetry models, where late decay of a TeV-scale bino generates the baryon asymmetry, linking cosmology with supersymmetric particle physics.

Contribution

It introduces a new baryogenesis scenario in mini-split SUSY with R-parity violation, supported by example models and viable parameter spaces, connecting cosmological and collider phenomenology.

Findings

Bino decay can produce sufficient baryon asymmetry in mini-split SUSY.

The models favor sfermion masses around 100-1000 TeV.

Potential signatures at LHC and low-energy experiments are discussed.

Abstract

We demonstrate here that the mini-split version of the Minimal Supersymmetric Standard Model (MSSM) including R-parity violating couplings naturally provides all the necessary ingredients for a novel baryogenesis mechanism. The baryogenesis is triggered by the late decay of a TeV scale bino after its thermal freezeout. A \mu-term larger than the sfermion masses is necessary for obtaining sufficient baryon asymmetry. Two example models of direct baryogenesis and leptogenesis are proposed, with viable parameter spaces presented. The cosmological conditions for the models--in particular, the requirements of a long lifetime of bino and sufficient baryon asymmetry--point towards the mini-split scale of $\sim$ 100-1000 TeV for the sfermion masses. This provides an independent motivation for mini-split SUSY, along with the constraints from flavor physics and Higgs mass measurement. We also discuss the potential multi-pronged search for the signatures of such models, including those at the Large Hadron Collider (LHC) and the low energy experiments at the intensity frontier.