The COMPASS Experiment at CERN

TL;DR

The COMPASS experiment at CERN utilizes high-intensity muon and hadron beams with advanced detection systems to study nucleon spin structure and hadron spectroscopy, providing detailed performance data and describing recent upgrades.

Contribution

This paper details the design, features, and performance of the COMPASS spectrometer, including recent upgrades, for investigating nucleon spin and hadron spectroscopy at CERN.

Findings

Successful operation of the spectrometer since 2002

Collection of data with muon and hadron beams

Implementation of a 2006 upgrade

Abstract

The COMPASS experiment makes use of the CERN SPS high-intensitymuon and hadron beams for the investigation of the nucleon spin structure and the spectroscopy of hadrons. One or more outgoing particles are detected in coincidence with the incoming muon or hadron. A large polarized target inside a superconducting solenoid is used for the measurements with the muon beam. Outgoing particles are detected by a two-stage, large angle and large momentum range spectrometer. The setup is built using several types of tracking detectors, according to the expected incident rate, required space resolution and the solid angle to be covered. Particle identification is achieved using a RICH counter and both hadron and electromagnetic calorimeters. The setup has been successfully operated from 2002 onwards using a muon beam. Data with a hadron beam were also collected in 2004. This article describes the main features and performances of the spectrometer in 2004; a short summary of the 2006 upgrade is also given.