Non-thermal production of Higgsino dark matter by late-decaying scalar fields

TL;DR

This paper investigates how late-decaying scalar fields can produce Higgsino dark matter non-thermally, allowing for lighter Higgsino masses at lower reheating temperatures, with detailed calculations including coannihilation and Sommerfeld effects.

Contribution

It provides a detailed analysis of non-thermal Higgsino dark matter production, incorporating coannihilation and Sommerfeld effects, and explores the parameter space with varying reheating temperatures.

Findings

Higgsino dark matter can be lighter than 1.2 TeV in non-thermal scenarios.

Reheating temperature influences the viable Higgsino mass for dark matter.

Proper inclusion of coannihilation and Sommerfeld effects is crucial for accurate relic abundance calculation.

Abstract

We study the non-thermal production of the Higgsino dark matter (DM). Assuming that the lightest neutral Higgsino is the lightest supersymmetric particle (LSP) in minimal supersymmetric standard model, we calculate the relic abundance of the Higgsino LSP produced by the decay of late-decaying scalar field. In the calculation of the relic abundance, we have properly included the effects of coannihilation as well as the non-perturbative effect (known as the Sommerfeld effect). Contrary to the case of the thermal-relic scenario, in which the observed DM abundance is realized with the Higgsino mass of ~ 1.2 TeV, Higgsino DM is possible with lighter Higgsino mass as the reheating temperature becomes lower than the Higgsino mass. The reheating temperature relevant for realizing the correct DM density is presented as a funciton of the Higgsino mass.