Threshold corrections to the radiative breaking of electroweak symmetry and neutralino dark matter in supersymmetric seesaw model

TL;DR

This paper investigates how threshold corrections from heavy singlet sneutrinos influence electroweak symmetry breaking and neutralino dark matter relic abundance in a supersymmetric seesaw model, potentially reducing fine-tuning and affecting dark matter properties.

Contribution

It demonstrates the impact of threshold corrections on Higgs mass parameters and neutralino dark matter relic density, providing new insights into supersymmetric seesaw models.

Findings

Threshold corrections can reduce fine-tuning in electroweak symmetry breaking.

Relic abundance of neutralino dark matter depends on the SSB B-parameter.

Dark matter can be a bino-Higgsino mixture consistent with observations.

Abstract

We study the radiative electroweak symmetry breaking and the relic abundance of neutralino dark matter in the supersymmetric type I seesaw model. In this model, there exist threshold corrections to Higgs bilinear terms coming from heavy singlet sneutrino loops, which make the soft supersymmetry breaking (SSB) mass for up-type Higgs shift at the seesaw scale and thus a minimization condition for the Higgs potential is affected. We show that the required fine-tuning between the Higgsino mass parameter mu and the SSB mass for up-type Higgs may be reduced at the electroweak scale, due to the threshold corrections. We also present how the parameter mu depends on the SSB B-parameter for heavy singlet sneutrinos. Since the property of neutralino dark matter is quite sensitive to the size of mu, we discuss how the relic abundance of neutralino dark matter is affected by the SSB B-parameter. Taking the SSB B-parameter of order of a few hundreds TeV, the required relic abundance of neutralino dark matter can be correctly achieved. In this case, dark matter is a mixture of bino and Higgsino, under the condition that gaugino masses are universal at the grand unification scale.