preparation of an experimental programme of
study of Generalized Parton Distributions (GPD)
with COMPASS at CERN
Expression of Interest : SPSC-EOI-005
Letter of Intent : SPSC-I-238
Proposal COMPASS-II submitted to SPSC, May 17, 2010 : SPSC-P-340
Questions posed by the Referees and Answers,September 3, 2010 : SPSC-M-772
Proposal recommanded by the SPSC on November 17 and approved by the RB on December 1, 2010
The framework of Generalized Parton Distributions (GPDs) is a novel and powerful tool for the investigation of the
nucleon structure. Accessible through
hard exclusive reactions, the GPDs provide a three-dimensional picture of how quarks and gluons build up the nucleon. In addition, they offer
the possibility of accessing the unknown parton orbital momenta. The high energies available at the CERN SPS, and the option of using either positive
or negative polarized muon beams, make the fixed-target COMPASS set-up a unique place for studying GPDs, through Deeply virtual Compton scattering
(DVCS). By installing a recoil detector around the target to ensure exclusivity of DVCS as well as
Deeply Virtual Meson Production (DVMP), the COMPASS apparatus could be converted into a facility
measuring exclusive reactions within a kinematic subspace that cannot be explored by any other existing or planned facility in the near future.
A first observation of single-photon production in the COMPASS apparatus was successfully achieved in autumn 2008.
A more quantitative test has been done in autumn 2009 during 10 days.
In the full-scale future programme, we propose to collect both DVCS and DVMP data using an unpolarized proton target
(and using a transversely polarized target)
in order to constrain mostly the GPD H in a first stage presented in the COMPASS-II proposal (and the GPD E in a future update of the proposal).
next GPD Meeting: Meeting at Lisbon on April 19, 2012
GPD Meeting at CERN on April 10, 2012
GPD Meeting at CERN on March 6, 2012
GPD Meeting at CERN on February 8, 2012
GPD Meeting by EVO on January 16, 2012
GPD Meeting at Saclay on December 6-7, 2011
GPD Meeting at CERN on November 16, 2011
GPD Meeting at CERN on October 12, 2011
GPD Meeting at CERN on September 6, 2011
TB Meeting at CERN on September 5, 2011
TB Meeting at CERN on July 15, and August 11 2011
GPD Meeting at Freiburg on July 13, 2011
GPD Meeting at CERN on June 22, 2011
GPD Meeting at CERN on May 4, 2011
GPD Meeting at Freiburg on March 29, 2011
GPD Meeting at CERN on February 9, 2011
GPD Meeting at Freiburg on January 19, 2011
GPD Meeting at CERN on November 17, 2010
GPD Meeting at Freiburg on October 20, 2010
GPD workshop at Trento 11-15 October, 2010
Next meeting on Wednesday, May 9, 2012 at 16:00 at CERN
E. Burtin- N. d'Hose: CAMERA preparation for the 2012 DVCS run( pdf )
Etienne Burtin: CAMERA status( pdf )
Philipp Joerg: Pulse analysis using CAMERA( pdf )
Oleg Kouznetsov: DVCS simulation with N2/C2F10 media of RICH radiator( pdf )
Nicole d'Hose: preparation run DVCS 2012( pdf )
Etienne Burtin: CAMERA status( pdf )
Nicolas Dufresne: Flux determination DVCS 2009 data( pdf )
Oleg Kouznetsov: Last reprocessing of DVCS 2009 and pi0 study( pdf )
Marie Boer: DVCS 2009 data analysis ( pdf )
Heiner Wollny: Towards Extraction of SDME for rho production from 2010 data ( pdf )
Pawel Sznajder: Exclusive production of neutral channels from 2010 data( pdf )
Etienne Burtin: CAMERA status( pdf )
Alexander Nagaytsev: ECAL0 preparation status( ppt )
Oleg Kouznetsov: Last reprocessing of DVCS 2009 and pi0 study( pdf )
Marie Boer: Comparisons of DIS analysis using mu+ (W38/W39) and mu- beam ( pdf )
Etienne Burtin: CAMERA status, construction of the mechnaical structure, photo-detection update, planning( pdf )
Etienne Burtin: Note on the choice of the Ring A PMTs( pdf )
Pawel Sznajder: Exclusive photon and pi0 production from 2010 data( pdf )
Nicole d'Hose: planning for 2012( pdf )
Etienne Burtin: CAMERA preparation( pdf )
Michal Rychter: Bases for ring B PMs ( pdf )
Reiner Geyer: Status of the LH2 target( pdf )
Vladimir Anosov: ECAL0 central hole studies (mechanics)( pdf )
Jens Barth: Muon Trigger for DVCS 2012( pdf )
Damien Neyret - Nicole d'Hose: DVCS2012 setup and pMM( pdf )
Pierre Guichon: Spin = ?( pdf )
Tobias Szameitat: CAMERA Test Data Analysis with GANDALF( pdf )
Kathatina Schmidt: Exclusive rho0 production (2007-10) ( pdf )
Pawel Sznajder: Exclusive omega production (2010) ( pdf )
Heiner Wollny: Exclusive rho0, phi, J/Psi (2007-10)( pdf )
Steffen Bauer: Comparison of DVCS mu+/mu- data based on t67 and t71( pdf )
Marie Boer: Comparison of DVCS mu+/mu- data based on t67 and t71( pdf )
Heiner Wollny: Quality Check on a spill-by-spill basis for DVCS 2009( pdf )
Oleg Kouznetsov: Inclusive Studies using DVCS 2009 data( pdf )
Katharina Schmidt: Discussion on y resolution using MC ( pdf )
Andrzej Sandacz: Effect of ECLA0 on acceptance for exclusive processes( pdf )
Marie Boer: DVCS test run 2009 - Comparison t54/t67 productions ( pdf )
Heiner Wollny: Exclusive phi in 2003-2004 and 2007 and rho0 in 2010 in transverse data. ( pdf )
Etienne Burtin: Update on CAMERA( pdf )
Nicolas du Fresne von Hohenesche: Flux determination DVCS test 2009( pdf )
Khatarina Schmidt: Update of 2003-2004 deuton AUT ( pdf )
Heiner Wollny: Some updates about rho0( pdf )
Andrzej Sandacz: Effect of ECAL0 on acceptance for exclusive processes( pdf )
Igor Savin: Beam test of 3*3 ECAL0 matrix at T9 and in muon halo at COMPASS( ppt )
Oleg Kouznetsov: pi0 excsluive: where we are( pdf )
Etienne Burtin: Update on CAMERA ( pdf )
Andrea Ferrero: Minimal lengths for LH2 target and cryostat( pdf )
Etienne Burtin: CAMERA, target zone layout, drawing of the LH2 target ( pdf )
Andrea Ferrero: Minimal lengths for target and cryostat( pdf )
Oleg Kouznetsov: Progress on DVCS 2009 data analysis (reproduction and vertexing)( pdf )
Oleg Kouznetsov: Status of the MC (DVCS, pi0, Lepto) ( pdf )
Marie Boer: Study of exclusivity cuts( pdf )
Claude Marchand: ECAL reconstruction and muon tracking: what did we learn from Primakoff( pdf )
Andrzej Sandacz: An update on predictions for exclusive pi0 production from Goloskokov and Kroll model( pdf )
Nicole d'Hose: Remarks on DVS kinematics for outgoing muons and photons; ECAL0: optimal size for 2012?( pdf )
Alain Magnon: Impact of Rich pipe on DVCS and Primakof( pdf )
Vladimir Anosov: 2012 GPD Pilot run setup( pdf )
Vladimir Anosov: RPD not on rail, installation of the target at the place of SI( pdf Top View ) ( pdf Side View )
Vladimir Anosov: RPD on rail, installation of the target outside the place of SI( pdf Top View ) ( pdf Side View )
Jorg Pretz: Trigger Upgrade for DVCS, HEMP (and DY)( pdf )
Heiner Wollny: Status of rho analysis( pdf )
Zinovi Krumshteyn: The ECAL0 status( ppt )
Nicole d'Hose: Report on the TB (DVCS experimental setup and priorities and proposal for a DVCS test run in 2012( pdf )
Etienne Burtin: Update on CAMERA( pdf )
Andrea Ferrero: A first look to the 2011 CAMERA test data ( pdf )
Katharina Schmidt: Status of xcheck for exclusive rho0 analysis ( pdf )
Heiner Wollny: Systematic checks for exclusive rho0 analysis (for Telco 17 May)( pdf )
Heiner Wollny: 2004 and 2007 exclusive rho0 analysis ( pdf )
Heiner Wollny: 2004 and 2004 exclusive rho0 analysis (for Telco 17 May)( pdf )
Minutes on 2004 and 2007 exclusive rho0 analysis ( pdf )
Andrea Ferrero: 2011 ring A tests and preparation ( pdf )
Heiner Wollny: 2007 exclusive rho0 analysis ( pdf )
Pawel Sznajder: 2004 exclusive rho0 analysis ( pdf )
Oleg Kouznetsov: 2009 new production DVCS analysis( pdf )
Andrzej Sandacz: 2009 DVCS simulation with different triggers ( ppt )
Andrea Ferrero: 2011 tests for CAMERA ( pdf )
Etienne Burtin: Report on CAMERA construction and LH2 target ( pdf )
Alain Magnon: GPD "dress rehearsal" or "test" run in 2012( pdf )
Pawel Sznajder: Systematic Studies on AUT asymmetry for exclusive rho production( pdf )
Heiner Wollny: Background Studies with 2007 PYTHIA sample ( pdf )
Alain Magnon: Global Efficiency 2008-2009 DVCS runs ( pdf )
Konrad Klimaszewski: Update of the outer trigger efficiency during the 2009 DVCS runs ( pdf )
Zinovi Krumshteyn: Tests of the various MAPD types at COMPASS( pdf )
Alexander Nagaytsev: ECAL0 project: status and plans( ppt )
Etienne Burtin: Update on CAMERA construction( pdf )
Alain Magnon: Study of Ring A occupancy in 2011( pdf )
Pawel Sznajder: Extraction of AUT asymmetry with non-exclusive background subtraction ( pdf )
Katharina Schmidt: rho0 cross check status ( pdf )
Heiner Wollny: Studies with 2007 PYTHIA sample ( pdf )
Andrzej Sandacz: First Draft on AUT asymmetry
Oleg Kouznetsov: Test production of 2009 DVCS data with new CORAL & LED/Laser & pi0 calibration( pdf )
Nicolas Du Fresne Von Hohenesche: Luminosity for 2009 DVCS runs ( pdf )
Andrea Ferrero: Completion of the ECALs Set-up( pdf )
Nicole d'Hose: DVCS tests in 2012
Etienne Burtin: Realization of the new RPD: CAMERA ( pdf )
Nicole d'Hose: Status of the DVCS preparation and future planning ( pdf )
Andrea Ferrero: Summary of Calorimetry Meeting ( pdf )
Zinovi Krumshteyn: ECAL0: status, results of tests and plans( ppt )
Katharina Schmidt: rho0 background studies ( pdf )
Pawel Sznajder: calculation of AUT asymmetry with non-exclusive background subtraction ( pdf )
Andrzej Sandacz: Dilution factor for exclusive rho0 with COMPASS polarized targets ( ppt )
Oleg Kouznetsov: pi0 background for 2009 DVCS Run ( pdf )
Alain Magnon: ECALs calibration ( pdf )
Morgan Murray: A Fast MC Generator for DVCS@COMPASS ( pdf )
Andrea ferrero: Status of pi0 MC ( pdf )
Jörg Pretz: Beam Analysis ( pdf )
Etienne Burtin: pi0 background for 2009 DVCS Run ( pdf )
Nicolas Du Fresne Von Hohenesche: Luminosity for 2009 DVCS runs ( pdf )
Monday 11 october 2010
Dieter Mueller (Bochum University): GPDs and TMDs in terms of effective light-cone wave functions ( pdf )
Franck Sabatié (CEA Saclay): Deeply Virtual Compton Scattering experiments ( pdf )
Horst Fischer (Freiburg University): DVCS Program at COMPASS-II ( pdf )
Hervé Moutarde (CEA Saclay): Extraction of the Compton Form Factor H from DVCS measurements in the quark sector ( pdf )
Kresimir Kumericki (Zagreb University): Extraction of GPDs from DVCS off unpolarized target ( pdf )
Kirill Semenov-Tian-Shansky (Ecole Polytechnique, Orsay University): Recent Status of the Dual Parametrization for GPDs ( pdf )
Harut Avakian (JLab): Transversity Program at CLAS ( ppt )
Morgan Murray (Glasgow University): DVCS@HERMES ( pdf )
Tuesday 12 october 2010
Oleg Teryaev (JINR Dubna): Transversity and TMD friends ( ppt )
Gunar Schnell (DESY): Experimental Results on Transversity and TMDs ( pdf )
Jian-Ping Chen (JLab): Transversity Experiments at JLab Hall A ( ppt )
Mauro Anselmino (Torino University and INFN): The Sivers and Collins functions ( pdf )
Marc Schlegel (Tuebingen University): Transverse Momentum Dependent Parton Distributions ( pdf )
Leonard Gamberg (PSU Berks): Gluonic Poles in "G"-GPM & Universality ( pdf )
Elliot Leader (Imperial College London): Polarized PDFs and Higher Twist from NLO Analysis of DIS and SIDIS ( pdf )
Eva-Maria Kabuss (Mainz University): Experimental Overview on Polarized Quark Distributions ( pdf )
Haiyan Gao (Duke University and Tsinghua University): Review on Nucleon Electromagnetic Form Factors (