The COMPASS Experiment at CERN

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.

84 papes, 74 figures

Cited by in corpus (156)

• The Spin Structure of the Nucleon
• The Status of Glueballs
• Parton Fragmentation Functions
• Measuring the leading hadronic contribution to the muon g-2 via $\mu e$ scattering
• Discovering New Light States at Neutrino Experiments
• Measurement of the Collins and Sivers asymmetries on transversely polarised protons
• Experimental investigation of transverse spin asymmetries in muon-p SIDIS processes: Sivers asymmetries
• Quark helicity distributions from longitudinal spin asymmetries in muon-proton and muon-deuteron scattering
• Observation of a J^PC = 1-+ exotic resonance in diffractive dissociation of 190 GeV/c pi- into pi- pi- pi+
• The Spin Structure Function $g_1^{\mathrm{p}}$ of the Proton and a Test of the Bjorken Sum Rule
• First measurement of transverse-spin-dependent azimuthal asymmetries in the Drell-Yan process
• Experimental investigation of transverse spin asymmetries in muon-p SIDIS processes: Collins asymmetries
• Collins and Sivers asymmetries in muonproduction of pions and kaons off transversely polarised proton
• Flavor-specific scalar mediators
• The Leptonic Higgs Portal
• The Polarised Valence Quark Distribution from semi-inclusive DIS
• Transverse spin effects in hadron-pair production from semi-inclusive deep inelastic scattering
• Probing Muonic Forces and Dark Matter at Kaon Factories
• Three-body Unitarity with Isobars Revisited
• A Novel Generic Framework for Track Fitting in Complex Detector Systems
• Flavour Separation of Helicity Distributions from Deep Inelastic Muon-Deuteron Scattering
• The COMPASS Setup for Physics with Hadron Beams
• A high-statistics measurement of transverse spin effects in dihadron production from muon-proton semi-inclusive deep-inelastic scattering
• Odd and Even Partial Waves of $\eta {\pi }^{-}$ and ${\eta }^{\prime }{\pi }^{-}$ in ${\pi }^{-}p\to {\eta }^{(\prime )}{\pi }^{-}p$ at $191\text{GeV}/c$
• Light isovector resonances in ${\pi }^{-}p\to {\pi }^{-}{\pi }^{-}{\pi }^{+}p$ at 190 GeV/$c$
• Observation of a new narrow axial-vector meson $a_1(1420)$
• Measurement of azimuthal hadron asymmetries in semi-inclusive deep inelastic scattering off unpolarised nucleons
• Extracting Electric Polarizabilities from Lattice QCD
• Leading and Next-to-Leading Order Gluon Polarisation in the Nucleon and Longitudinal Double Spin Asymmetries from Open Charm Muoproduction
• Hadron Transverse Momentum Distributions in Muon Deep Inelastic Scattering at 160 GeV/$c$
• Leading-Order Determination of the Gluon Polarization from high-$p_T$ Hadron Electroproduction
• Transverse-momentum-dependent Multiplicities of Charged Hadrons in Muon-Deuteron Deep Inelastic Scattering
• Transverse Spin Structure of the Nucleon through Target Single Spin Asymmetry in Semi-Inclusive Deep-Inelastic $(e,e^{\prime }{\pi }^{\pm })$ Reaction at Jefferson Lab
• Leading order determination of the gluon polarisation from DIS events with high-p_T hadron pairs
• Resonance Production and $\pi \pi$ S-wave in ${\pi }^{-}+p\to {\pi }^{-}{\pi }^{-}{\pi }^{+}+p_{recoil}$ at 190 GeV/c
• Light-Meson Spectroscopy with COMPASS
• Sivers asymmetry extracted in SIDIS at the hard scale of the Drell-Yan process at COMPASS
• Final COMPASS results on the deuteron spin-dependent structure function $g_1^{\mathrm{d}}$ and the Bjorken sum rule
• Multiplicities of charged pions and unidentified charged hadrons from deep-inelastic scattering of muons off an isoscalar target
• Measurement of the charged-pion polarisability
• Transverse Extension of Partons in the Proton probed by Deeply Virtual Compton Scattering
• Measurement of the Longitudinal Spin Transfer to Lambda and Anti-Lambda Hyperons in Polarised Muon DIS
• Multiplicities of charged kaons from deep-inelastic muon scattering off an isoscalar target
• Gluon Polarisation in the Nucleon and Longitudinal Double Spin Asymmetries from Open Charm Muoproduction
• First lattice QCD study of the gluonic structure of light nuclei
• Conceptual design of the Spin Physics Detector
• Prospects in the search for a new light $Z^{\prime }$ boson with the NA64$\mu$ experiment at the CERN SPS
• Electric polarizability of neutral hadrons from dynamical lattice QCD ensembles
• Model Selection for Pion Photoproduction
• Triangle Singularity as the Origin of the $a_1(1420)$
• New pixelized Micromegas detector with low discharge rate for the COMPASS experiment
• The next generation of laser spectroscopy experiments using light muonic atoms
• Search for exclusive photoproduction of Z${}_c^{\pm }$(3900) at COMPASS
• Azimuthal asymmetries of charged hadrons produced by high-energy muons scattered off longitudinally polarised deuterons
• First measurement of the Sivers asymmetry for gluons from SIDIS data
• Status of the MUonE experiment
• Search for muoproduction of $X(3872)$ at COMPASS and indication of a new state $\tilde{X}(3872)$
• Transverse target spin asymmetries in exclusive ${\rho }^0$ muoproduction
• Longitudinal double-spin asymmetry $A_1^{\mathrm{p}}$ and spin-dependent structure function $g_1^{\mathrm{p}}$ of the proton at small values of $x$ and $Q^2$
• Double spin asymmetry in exclusive rho^0 muoproduction at COMPASS
• The polarizability of the pion: no conflict between dispersion theory and chiral perturbation theory
• Measurement of the cross section for hard exclusive ${\pi }^0$ leptoproduction
• The exotic meson ${\pi }_1(1600)$ with $J^{PC}=1^{-+}$ and its decay into $\rho (770)\pi$
• The MPGD-Based Photon Detectors for the upgrade of COMPASS RICH-1 and beyond
• Measurement of $P_T$-weighted Sivers asymmetries in leptoproduction of hadrons
• Exclusive rho^0 muoproduction on transversely polarised protons and deuterons
• Azimuthal asymmetries of charged hadrons produced in high-energy muon scattering off longitudinally polarised deuterons
• First Measurement of Chiral Dynamics in π^- γ-> π^- π^- π^+
• ${\Lambda }_c^{+}(2940)$ photoproduction off the neutron
• Performance of Multiplexed XY Resistive Micromegas detectors in a high intensity beam
• Six "beyond Collins and Sivers" transverse spin asymmetries at COMPASS
• Chiral corrections to ${\pi }^{-}\gamma \to 3\pi$ processes at low energies
• The Thick Gas Electron Multiplier and its derivatives: physics, technologies and applications
• K${}^{-}$ over K${}^{+}$ multiplicity ratio for kaons produced in DIS with a large fraction of the virtual-photon energy
• Measurement of radiative widths of $a_2(1320)$ and ${\pi }_2(1670)$
• A Very High Momentum Particle Identification Detector
• Final state interactions and hadron quenching in cold nuclear matter
• A study of muon-electron elastic scattering in a test beam
• Semi-inclusive lepto-production of hidden-charm exotic hadrons
• Interplay among transversity induced asymmetries in hadron leptoproduction
• Transverse spin dependent azimuthal asymmetries at COMPASS
• Compton Scattering off Pions and Electromagnetic Polarizabilities
• Particle Identification at FCC-ee
• A Large Ungated TPC with GEM Amplification
• Pattern recognition and PID for COMPASS RICH-1
• New pixelized Micromegas detector for the COMPASS experiment
• Exclusive $\omega$ meson muoproduction on transversely polarised protons
• Numerical estimation of discharge probability in GEM-based detectors
• Beam impact tests of a prototype target for the Beam Dump Facility at CERN: experimental setup and preliminary analysis of the online results
• Study of Σ(1385) and Ξ(1321) hyperon and antihyperon production in deep inelastic muon scattering
• Exploring Baryon Resonances with Transition Generalized Parton Distributions: Status and Perspectives
• Electromagnetic and gravitational form factors in simulated QED and Yukawa model
• Radiative Corrections to High Energy Lepton Bremsstrahlung on Heavy Nuclei
• Collins and Sivers transverse-spin asymmetries in inclusive muoproduction of ${\rho }^0$ mesons
• Measurement of the Cross Section for High-p_T Hadron Production in Scattering of 160 GeV/c Muons off Nucleons
• Azimuthal asymmetries in the unpolarized SIDIS cross section at COMPASS
• Measurement of neutron and proton analyzing powers on $C$, $CH$, $C{H}_2$ and $Cu$ targets in the momentum region 3-4.2 GeV/c
• Photoproduction of $a_2(1320)$ in a Regge model
• Precision spectroscopy with COMPASS and the observation of a new iso-vector resonance
• Transversity distributions from difference asymmetries in semi-inclusive DIS
• Large-Area Sandwich Veto Detector with WLS Fibre Readout for Hadron Spectroscopy at COMPASS
• D* and D Meson Production in Muon Nucleon Interactions at 160 GeV/c
• Spin alignment and violation of the OZI rule in exclusive $\omega$ and $\varphi$ production in pp collisions
• The production of neutral $N^{\ast }(11052)$ resonance with hidden beauty from ${\pi }^{-}p$ scattering
• Phenomenological model of multiphoto-production of charged pion pairs on the proton
• Extraction of characteristic constants in QCD with perturbative and nonperturbative methods
• The high voltage system with pressure and temperature corrections for the novel MPGD-based photon detectors of COMPASS RICH-1
• FPGA based data acquisition system for COMPASS experiment
• Polarized nuclear target based on parahydrogen induced polarization
• Quadrupole polarizabilities of the pion in the Nambu--Jona-Lasinio model
• Control Systems: an Application to a High Energy Physics Experiment (COMPASS)
• Deep-Inelastic Scattering at TeV Energies with LHC Muons
• Development and Performance Verification of the GANDALF High-Resolution Transient Recorder System
• Antiproton over proton and K${}^{-}$ over K${}^{+}$ multiplicity ratios at high $z$ in DIS
• Multiple hit reconstruction in large area multiplexed detectors
• Implementation of mean-timing and subsequent logic functions on an FPGA
• Concept for an Electron Ion Collider (EIC) detector built around the BaBar solenoid
• Direct measurements of the properties of Thick-GEM reflective photocathodes
• Axial anomaly and the interplay of quark loops with pseudoscalar and vector mesons in the gamma* --> pi+ pi0 pi- process
• Highlights from the COMPASS experiment at CERN -- Hadron spectroscopy and excitations
• MPGD-based photon detectors for the upgrade of COMPASS RICH-1 and beyond
• On duality of Drell-Yan and J/psi production processes
• Next Frontiers in Particle Physics Detectors: INSTR2020 Summary and a Look into the Future
• First Results of the PixelGEM Central Tracking System for COMPASS
• Searching and identifying leptoquarks through low-energy polarized scattering processes $e^{-}p\to e^{-}{\Lambda }_c$
• ΔG/G results from the COMPASS experiment for Q^2 > 1 GeV^2, using high p_T hadrons
• A Large-Scale FPGA-Based Trigger and Dead-Time Free DAQ System for the Kaos Spectrometer at MAMI
• Double $J/\psi$ production in pion-nucleon scattering at COMPASS
• Micro-Pattern Gas Detectors for Charged-Particle Tracking and Muon Detection
• R&D Proposal, RD51 Extension Beyond 2018
• Radiative corrections to neutral pion-pair production
• Measurement of the longitudinal spin structure of the proton by COMPASS
• Test for exotic isoscalar resonance dominating $D^0\to {\pi }^{+}{\pi }^{-}{\pi }^0$ decays
• COMPASS Results on Transverse Single-Spin Asymmetries
• A Prototype Scalable Readout System for Micro-pattern Gas Detectors
• Search for muoproduction of the X(3872) at COMPASS
• Odd and Even Partial Waves of ηπ^- and η'π^- in 191 GeV/c π^-p
• Hadron Spectroscopy with COMPASS at CERN
• Gluon Polarisation Measurements @ COMPASS
• Tests of Three-Flavor Chiral Perturbation Theory
• Baryon Spectroscopy at COMPASS
• Hard Quasi-real Photo-production of Charged Hadrons at COMPASS energies
• Meson spectroscopy with COMPASS
• Transverse Spin Physics at COMPASS
• Making the $\mu$OST of the Muon Collider
• Search for Axion Like Particles produced via the Primakoff process at COMPASS
• Diffractive Dissociation of 190 GeV/c ${\pi }^{-}$ into ${\pi }^{-}{\pi }^{+}{\pi }^{-}$ Final States at COMPASS
• COMPASS Hadron Spectroscopy -- Final states involving neutrals and kaons
• SU(3) Gauge Symmetry: An Experimental Review of Diffractive Physics in e+p, p+p, p+A, and A+A Collision Systems
• Spin Physics at COMPASS
• Transversity Measurements at COMPASS
• Transverse Spin Effects at COMPASS
• 2-D straw detectors with high rate capability
• Pion Polarizability in the NJL model and Possibilities of its Experimental Studies in Coulomb Nuclear Scattering
• Work on the interplay among $h^{+}$, $h^{-}$ and hadron pair transverse spin asymmetries in SIDIS
• The MPGD-Based Photon Detectors for the upgrade of COMPASS RICH-1