# How Heavy can Neutralino Dark Matter be?

## TL;DR

This paper investigates the maximum possible mass of neutralino dark matter consistent with observed relic abundance, focusing on scenarios with near-degenerate masses leading to a second freeze-out after the QCD phase transition.

## Contribution

It introduces the concept of a second freeze-out due to near-degenerate neutralino and colored sparticles, allowing for neutralino masses well above 100 TeV.

## Key findings

- Neutralino mass can exceed 100 TeV with near-degenerate sparticles.
- Second freeze-out significantly enhances dark matter annihilation.
- Implications for dark matter detection strategies.

## Abstract

What is the upper limit of the mass of the neutralino dark matter whose thermal relic is consistent with the observation? If the neutralino dark matter and colored sparticles are extremely degenerated in mass, with a mass difference less than the QCD scale, the dark matter annihilation is significantly increased and enjoys the "second freeze-out" after the QCD phase transition. In this case, the neutralino dark matter with a mass much greater than 100 TeV can realize the correct dark matter abundance. We study the dark matter abundance and its detection in the case of such highly degenerated mass spectrum of the neutralino dark matter and colored supersymmetric particles.