Sensitivity to millicharged particles in future proton-proton collisions at the LHC

TL;DR

This paper assesses the potential of future LHC experiments to detect or exclude millicharged particles with very small electric charges, using prototype detector data and proposing new detector configurations.

Contribution

It introduces a novel detector design and provides sensitivity projections for detecting millicharged particles at the LHC during Run 3 and high luminosity phases.

Findings

Run 3 could exclude particles with masses 10 MeV to 45 GeV for charges 0.003e to 0.3e.

High luminosity LHC could extend exclusion to 10 MeV to 80 GeV for charges 0.0018e to 0.3e.

Prototype detector data informs background estimates and detector performance.

Abstract

We report on the expected sensitivity of dedicated scintillator-based detectors at the LHC for elementary particles with charges much smaller than the electron charge. The dataset provided by a prototype scintillator-based detector is used to characterise the performance of the detector and provide an accurate background projection. Detector designs, including a novel slab detector configuration, are considered for the data taking period of the LHC to start in 2022 (Run 3) and for the high luminosity LHC. With the Run 3 dataset, the existence of new particles with masses between 10 MeV and 45 GeV could be excluded at 95% confidence level for charges between 0.003e and 0.3e, depending on their mass. With the high luminosity LHC dataset, the expected limits would reach between 10 MeV and 80 GeV for charges between 0.0018e and 0.3e, depending on their mass