CP-Violating Effects in Neutralino Scattering and Annihilation

TL;DR

This paper explores how CP violation in supersymmetric models can significantly alter neutralino dark matter detection rates, enhancing indirect signals while suppressing direct detection, depending on the phase of certain parameters.

Contribution

It demonstrates that CP-violating effects can drastically change dark matter detection prospects, revealing new viable parameter regions in supersymmetric models.

Findings

CP violation can increase annihilation rates by factors of 10^6.

CP violation can decrease scattering rates by factors of 10^{-7}.

Certain parameter regions become allowed or excluded based on CP violation.

Abstract

We show that in some regions of supersymmetric parameter space, CP violating effects that mix the CP-even and CP-odd Higgs bosons can enhance the neutralino annihilation rate, and hence the indirect detection rate of neutralino dark matter, by factors of 10^6. The same CP violating effects can reduce the neutralino scattering rate off nucleons, and hence the direct detection rate of neutralino dark matter, by factors of 10^{-7}. We study the dependence of these effects on the phase of the trilinear coupling A, and find cases in the region being probed by dark matter searches which are experimentally excluded when CP is conserved but are allowed when CP is violated.