LHCb potential to discover long-lived new physics particles with lifetimes above 100 ps

TL;DR

This paper shows that the LHCb detector can significantly improve its sensitivity to long-lived particles with lifetimes over 100 ps by using a new track reconstruction algorithm, expanding its discovery potential.

Contribution

It introduces the Downstream algorithm enabling LHCb to detect long-lived particles without relying on vertex tracker hits, enhancing its role as a lifetime frontier experiment.

Findings

LHCb can match sensitivity of proposed beyond-main-LHC experiments for various LLP models.

The new algorithm improves detection of particles like heavy neutral leptons and dark photons.

LHCb's potential extends to a broad class of long-lived particles with lifetimes above 100 ps.

Abstract

For years, it has been believed that the main LHC detectors can only restrictively play the role of a lifetime frontier experiment exploring the parameter space of long-lived particles (LLPs) - hypothetical particles with tiny couplings to the Standard Model. This paper demonstrates that the LHCb experiment may become a powerful lifetime frontier experiment if it uses the new Downstream algorithm reconstructing tracks that do not let hits in the LHCb vertex tracker. In particular, for many LLP scenarios, LHCb may be as sensitive as the proposed experiments beyond main LHC detectors for various LLP models, including heavy neutral leptons, dark scalars, dark photons, and axion-like particles.