# Performance of the LHCb RICH detectors during the LHC Run II

## TL;DR

This paper evaluates the LHCb RICH detectors' performance during LHC Run II, highlighting improvements, operational changes, and their impact on particle identification crucial for precision physics analyses.

## Contribution

It reports on the performance of the LHCb RICH system during Run II, including detector refurbishments and operational modifications that enhanced particle identification capabilities.

## Key findings

- Successful refurbishment of photon detectors using new vacuum tech
- Removal of aerogel radiator and its impact on performance
- Integration of RICH data into all trigger streams for the first time

## Abstract

The LHCb RICH system provides hadron identification over a wide momentum range (2-100 GeV/c). This detector system is key to LHCb's precision flavour physics programme, which has unique sensitivity to physics beyond the standard model. This paper reports on the performance of the LHCb RICH in Run II, following significant changes in the detector and operating conditions. The changes include the refurbishment of significant number of photon detectors, assembled using new vacuum technologies, and the removal of the aerogel radiator. The start of Run II of the LHC saw the beam energy increase to 6.5 TeV per beam and a new trigger strategy for LHCb with full online detector calibration. The RICH information has also been made available for all trigger streams in the High Level Trigger for the first time.