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# Leptogenesis after chaotic sneutrino inflation and the supersymmetry breaking scale

Björkeroth, Fredrik, King, Stephen F., Schmitz, Kai and Yanagida, Tsutomu T. (2017) Leptogenesis after chaotic sneutrino inflation and the supersymmetry breaking scale. Nuclear Physics B, 916, 688-708.

Record type: Article

## Abstract

We discuss resonant leptogenesis arising from the decays of two nearly-degenerate right-handed neutrinos, identified as the inflaton and stabiliser superfields in a model of chaotic sneutrino inflation. We compare an analytical estimate of the baryon asymmetry $\eta_B$ in the Boltzmann approximation to a numerical solution of the full density matrix equations, and find that the analytical result fails to capture the correct physics in certain regions of parameter space. The observed baryon asymmetry can be realised for a breaking of the mass degeneracy as small as $\mathcal{O}(10^{-8})$. The origin of such a small mass splitting is explained by considering supersymmetry (SUSY) breaking in supergravity, which requires a constant in the superpotential of the order of the gravitino mass $m_{3/2}$ to cancel the cosmological constant. This yields additional terms in the (s)neutrino mass matrices, lifting the degeneracy and linking $\eta_B$ to the SUSY breaking scale. We find that achieving the correct baryon asymmetry requires a gravitino mass $m_{3/2} \geq \mathcal{O}(100)$ TeV.

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Accepted/In Press date: 20 January 2017
e-pub ahead of print date: 27 January 2017
Published date: March 2017
Additional Information: v2: 25 pages, 4 figures; version published in NPB, minor corrections. v1: 24 pages, 4 figures
Keywords: hep-ph
Organisations: Theory Group

## Identifiers

Local EPrints ID: 410563
URI: http://eprints.soton.ac.uk/id/eprint/410563
ISSN: 0550-3213

## Catalogue record

Date deposited: 09 Jun 2017 09:07

## Contributors

Author: Fredrik Björkeroth
Author: Stephen F. King
Author: Kai Schmitz
Author: Tsutomu T. Yanagida