# Fast component re-emission in Xe-doped liquid argon

## TL;DR

This study confirms the fast component re-emission in Xe-doped liquid argon, quantifies energy transfer rates, and demonstrates improved pulse shape discrimination at high Xe concentrations without TPB.

## Contribution

First experimental confirmation of fast component re-emission in Xe-doped liquid argon and analysis of its effects on detector performance.

## Key findings

- Fast component re-emission confirmed in Xe-doped LAr.
- High Xe concentration improves PSD efficiency.
- LAr+Xe mixture remains stable at high Xe levels.

## Abstract

We present the first direct experimental confirmation of the fast component re-emission in liquid argon (LAr) doped with xenon (Xe). This effect was studied at various Xe concentrations up to $\sim$3000 ppm. The rate constant of energy transfer for the fast component was quantified. It was shown that LAr doped with a high concentration of Xe without TPB has a better PSD efficiency than pure LAr or Xe-doped LAr with TPB. The stability of LAr+Xe mixture was tested for the first time at high Xe concentration for long continuous runtimes.