dE/dx from boosted long-lived particles

TL;DR

This paper investigates highly boosted long-lived charged particles at colliders, showing they can explain recent ATLAS $dE/dx$ excesses without conflicting with other measurements.

Contribution

It introduces a new class of models where boosted LLPs from heavy resonance decays provide distinctive collider signatures and can account for observed anomalies.

Findings

Boosted LLP scenarios can explain ATLAS $dE/dx$ excess.

Such models are consistent with ionisation and time-of-flight measurements.

They offer a novel approach to collider searches for long-lived particles.

Abstract

At colliders massive long-lived charged particles could be revealed through their anomalously large ionisation energy loss $dE/dx$. In this paper we explore a class of scenarios in which the LLPs are particularly boosted, owing to production from the decay of a heavy parent resonance. Such scenarios give rise to unique signatures as compared to traditionally considered $dE/dx$ new-physics benchmarks. We demonstrate that this class of models, unlike traditional new-physics theories, can explain the recently reported excess of events in the $dE/dx$ search by the ATLAS collaboration without conflicting with the determination of $\beta$ from ionisation and time-of-flight measurements.