# New Long Lived Particles Searches in Heavy Ion Collisions at the LHC

## TL;DR

Heavy ion collisions at the LHC offer a promising new avenue for detecting long-lived particles with displaced vertices, especially through trigger modifications that enhance observability of low transverse momentum events.

## Contribution

This work demonstrates the potential of heavy ion collisions at the LHC for New Physics searches, highlighting trigger modifications to improve detection of long-lived particles.

## Key findings

- Trigger modifications can increase observable events by orders of magnitude.
- Lighter ion collisions are advantageous for New Physics searches.
- Heavy neutrinos in the Neutrino Minimal Standard Model are a promising target.

## Abstract

We show that heavy ion collisions at the LHC provide a promising environment to search for signatures with displaced vertices in well-motivated New Physics scenarios. Compared to proton collisions, they offer several advantages, i) the number of parton level interactions per collision is larger, ii) there is no pile-up, iii) the lower instantaneous luminosity compared to proton collisions allows to operate the LHC experiments with very loose triggers, and iv) there are new production mechanisms that are absent in proton collisions. In the present work we focus on the third point and show that the modification of the triggers alone can increase the number of observable events by orders of magnitude if the long lived particles are predominantly produced with low transverse momentum. Our results show that collisions of ions lighter than lead are well-motivated from the viewpoint of searches for New Physics. We illustrate this for the example of heavy neutrinos in the Neutrino Minimal Standard Model.