# Smallest Halos in Thermal Wino Dark Matter

## TL;DR

This paper investigates the smallest halos formed by thermal wino dark matter, focusing on their properties and impact on indirect detection signals, with implications for understanding supersymmetry and dark matter detection.

## Contribution

It provides a detailed analysis of the smallest halos of thermal wino dark matter, including kinetic equilibrium and density contrast effects, improving estimates of the boost factor for indirect detection.

## Key findings

- Neutral wino remains in kinetic equilibrium via inelastic processes.
- Density contrast shows overshooting at dark acoustic oscillation peaks.
- Rigorous estimate of the boost factor for indirect detection.

## Abstract

(Mini) split supersymmetry explains the observed Higgs mass and evades stringent constraints, while keeping good features of TeV-scale supersymmetry other than the little hierarchy problem. Such scenarios naturally predict thermal wino dark matter whose mass is around $3 \, {\rm TeV}$. Its non-perturbatively enhanced annihilation is a promising target of indirect detection experiments. It is known that identifying the smallest halos is essential for reducing an uncertainty in interpreting indirect detection experiments. Despite its importance, the smallest halos of thermal wino dark matter have not been well understood and thus are investigated in this work. In particular, we remark on two aspects: 1) the neutral wino is in kinetic equilibrium with primordial plasma predominantly through inelastic processes involving the slightly heavier charged wino; and 2) the resultant density contrast shows larger powers at dark acoustic oscillation peaks than in cold dark matter, which is known as an overshooting phenomenon. By taking them into account, we provide a rigorous estimate of the boost factor. Our result facilitates accurately pinning down thermal wino dark matter through vigorous efforts in indirect detection experiments.