Probing exotic long-lived particles from the prompt side using the CONTUR method

TL;DR

This paper introduces an adapted CONTUR method to constrain exotic long-lived particles using prompt state measurements, enabling exploration of models with very short or very long lifetimes often missed by direct searches.

Contribution

The authors modify the CONTUR workflow to incorporate long-lived particle decay timing and recoil effects, expanding the method's sensitivity to new physics models.

Findings

Set new constraints on dark matter and hidden sector models.

Effective in probing very short and very long-lived particle regimes.

Demonstrates the method's ability to complement direct search strategies.

Abstract

A method to derive constraints on new physics models featuring exotic long-lived particles using detector-corrected measurements of prompt states is presented. The CONTUR workflow is modified to either account for the fraction of long-lived particles which decay early enough to be reconstructed as prompt, or to be sensitive to the recoil of such particles against a prompt system. This makes it possible to determine how many of signal events would be selected in the RIVET routines which encapsulate the fiducial regions of dozens of measurements of Standard Model processes by the ATLAS and CMS collaborations. New constraints are set on several popular exotic long-lived particle models in the very short-lifetime or very long-lifetime regimes, which are often poorly covered by direct searches. The probed models include feebly-interacting dark matter, hidden sector models mediated by a heavy neutral scalar, dark photon models and a model featuring photo-phobic axion-like particles.