WMAP Dark Matter Constraints on Yukawa Unification with Massive Neutrinos

TL;DR

This paper examines how massive neutrinos and lepton mixing influence dark matter constraints in Yukawa unification models, expanding the viable parameter space for neutralino dark matter especially with positive .

Contribution

It demonstrates that large lepton mixing can modify bottom quark mass predictions, allowing Yukawa unification at large  and positive , thus broadening dark matter parameter space.

Findings

Allowed parameter space increases for positive , especially with resonant relic density.

Negative  scenarios are strongly constrained by WMAP data.

Lepton mixing impacts the viability of Yukawa unification models.

Abstract

We revisit the WMAP dark matter constraints on Yukawa Unification in the presence of massive neutrinos. The large lepton mixing indicated by the data may modify the predictions for the bottom quark mass, enabling Yukawa unification also for large $\tan\beta$, and for positive $\mu$ that was previously disfavoured. As a result, the allowed parameter space for neutralino dark matter increases for positive $\mu$, particularly for areas with resonant enhancement of the neutralino relic density. On the contrary, a negative $\mu$ is not easily compatible with large lepton mixing and Dirac neutrino Yukawa couplings, and the WMAP allowed parameter space is in this case strongly constrained.