COMPASS muon programme Alain Magnon DAPNIA/SPhN (CEA Saclay) On behalf of the COMPASS Collaboration A.Magnon COMPASS week, PRAGUE August 1st-5 2005

COMPASS week, PRAGUE August 1st-5 2005 Content Highlights about results, upgrades, prospects, - SPSC Villars meeting 22-28 Sept 2004 - SPSC71 meeting 3 May 2005 (G. Mallot) - SPSC72 meeting 5 July 2005 - Talks by Paolo P., Sonia H. & Alex K. (section 4) Vadim A. (section 5) 2006 & beyond ? A.Magnon COMPASS week, PRAGUE August 1st-5 2005

Villars 2004 Report on the SPSC Villars Meeting September 22-28 2004 John Dainton University of Liverpool, GB (on behalf of the SPSC) A.Magnon COMPASS week, PRAGUE August 1st-5 2005

Villars 2004 Framework Machines and Beams Heavy Ions Neutrinos Soft and Hard Protons Antiproton Physics Flavour Physics Other Topics Summary Report on the SPSC Villars Meeting September 22-28 2004 John Dainton University of Liverpool, GB (on behalf of the SPSC) COMPASS Report on the SPSC Villars meeting by John Dainton, University of Liverpool (CERN-SPSC-2005-010 SPSC-M-730 February 28th 2005, available on Web) A.Magnon COMPASS week, PRAGUE August 1st-5 2005

COMPASS Collaboration Bielefeld, Bochum, Bonn (ISKP, PI), Burdwan and Calcutta, CERN, Dubna (LPP, LNP), Erlangen, Freiburg, Lisbon, Mainz, Moscow (INR, LPI, MSU), Munich-LMU, Munich-TU, Nagoya, Prague (CU, CUT, TUL), Protvino, Saclay, Tel Aviv, Torino (Univ., INFN), Trieste (Univ.,INFN), Warsaw (SINS), Warsaw (TU) More than 220 physicists from 28 Institutes A.Magnon COMPASS week, PRAGUE August 1st-5 2005

Hadron structure and spectroscopy Physics programme Stephan Paul talk Hadron structure and spectroscopy Muon beam programme Quarks and gluon polarisation in polarised (longitudinal) nucleons Transverse spin distribution Lambda polarisation Diffractive vector-meson production Hadron beam programme Polarisibility of pions and kaons (Primakoff reaction) Exotics q-states, glue balls Semi-leptonic decays of charmed baryons Double charmed hadrons GPDs (DVCS, HEMP) - under consideration - Nicole d’Hose talk A.Magnon COMPASS week, PRAGUE August 1st-5 2005

COMPASS week, PRAGUE August 1st-5 2005 Spectrometer 2002 -> 2004 trigger-hodoscopes DW45 straws SM2 dipole Muon-filter2,MW2 RICH_1 HCAL1 Gem_11 SM1 dipole ECAL2,HCAL2 Polarised Target MWPC Gems Scifi SPS 160 GeV 2.108m/spill Muon-filter1,MW1 Veto straws,MWPC,Gems,SciFi Gems,SciFi,DCs,straws Silicon SciFi Micromegas,DC,SciFi A.Magnon COMPASS week, PRAGUE August 1st-5 2005

COMPASS week, PRAGUE August 1st-5 2005 COMPASS objectives Original programme set for about 5 years (1) of running at 150 days/year with 14.4s supercyle and eSPS = 80%. i.e. 7.2  105 spills/year i.e. 1019 PoT/year (2  108 m/spill) (1) HMC (4 years) - CHEOPS (2 years) A.Magnon COMPASS week, PRAGUE August 1st-5 2005

COMPASS week, PRAGUE August 1st-5 2005 Data taking 2002 – 2004 2002 2003 2004 Beam (1) 106days 90d 110d єSPS+BL (2) .89 .63 .67 Preparation ~30d 7d 3d єSpectro(3) .77 .83 .87 Data taking (4) 44d 39d 61d muon (L/T) 33d/11d 30d/9d 47d/14d 2004 19d 4d 15d hadron (1) Scheduled beam excluding MDs (4) L/T Longitudinal/Transverse sharing ~ 80/20 (2) Inefficiency from SPS, beam line, etc (3) ~ 0.90 additional due to time needed to rotate spin and calibrate spectrometer A.Magnon COMPASS week, PRAGUE August 1st-5 2005

COMPASS week, PRAGUE August 1st-5 2005 Data taking 2002 - 2004 muon: 2002 + 2003 + 2004 -> 11.6  105 spills request: 7.2  105 spills/year  2.5 (proposal-year) We got ~ 1.6 (proposal-year) Pilot hadron run: 2004 -> ~ 0.7  105 spills A.Magnon COMPASS week, PRAGUE August 1st-5 2005

COMPASS week, PRAGUE August 1st-5 2005 Physics results Highlights (SPSC71 status report) : - g1 - transversity - L polarisation -DG/G from high pT hadron pairs -DG/G from open-charm - more … A.Magnon COMPASS week, PRAGUE August 1st-5 2005

COMPASS week, PRAGUE August 1st-5 2005 g1 of the deuteron 2002-2003 data most precise measurement for 0.004 < x < 0.03 PLB 612 (2005) 154 new NLO QCD fit, precision of a0 improves factor 2 (<Q2> = 4 GeV2) A.Magnon COMPASS week, PRAGUE August 1st-5 2005

COMPASS week, PRAGUE August 1st-5 2005 Towards transversity single transverse-spin asymmetries (2002 data) - Collins: related to transverse quark distributions - Sivers : related to intrinsic kT h+ h- Collins PRL 94,202002 (2005) Sivers A.Magnon COMPASS week, PRAGUE August 1st-5 2005

COMPASS week, PRAGUE August 1st-5 2005 Quark polarimeters all asymmetries compatible with zero measure product of chiral-odd FF and transverse-PDF - is the analysing power of Collins FF small? or are the transverse parton distributions small? (proton-neutron cancellation in deuteron ?) try other polarimeters - interference FF of two hadrons - lambda polarisation A.Magnon COMPASS week, PRAGUE August 1st-5 2005

Theoretical work on Sivers SSA “Extracting the Sivers function from polarized SIDIS data and making predictions” - Phenomelogical model whose parameters are constrained by HERMES proton measurements. - COMPASS 2002 preliminary results for Sivers effect are in agreement with the model. Are now COMPASS data included in the fit? M. Anselmino et al. hep-ph/057181 (including HERMES Prel. Results shown at DIS05) A.Magnon COMPASS week, PRAGUE August 1st-5 2005

Theoretical work on Sivers SSA “Predictions of Sivers asymmetries on a proton target” M. Anselmino et al. hep-ph/057181 A.Magnon COMPASS week, PRAGUE August 1st-5 2005

Expected accuracy for Collins asymmetries 2002 2002-4 2006 A.Magnon COMPASS week, PRAGUE August 1st-5 2005

ΔG/G from Photon-Gluon Fusion Strategies to suppress background: 1) Open charm production: q = c unique, no background charm fragmentation, 1.2 D0 per event D0 -> K- π+ (BR 4%), D*+(~20%) -> D0 π+ 2) High-pT hadron pair production: q=u,d,s background from non PGF events & resolved g pQCD scale set by: 1) ŝ > 4mc2 or 2) ŝ > (pt1+pt2)2 LOW STAT. HIGH STAT. Photon Gluon Fusion Needed since Q2 ~ 0 A.Magnon COMPASS week, PRAGUE August 1st-5 2005

ΔG/G from high-pT hadron pair e, m h1 h2 N Photon Gluon Fusion Leading order Process QCD-Compton measured aLL : calculable partonic asymmetries R : Monte-Carlo (Lepto/Phytia depending on Q2) A.Magnon COMPASS week, PRAGUE August 1st-5 2005

COMPASS week, PRAGUE August 1st-5 2005 high-pT hadron pairs Q2<1GeV2 Q2>1GeV2 Q2 < 1GeV2 250000 evts Q2 > 1GeV2 28000 evts 2002 and 2003 data - pT,1, pT,2 > 0.7 GeV, p2T,1 + p2T,2 > 2.5 GeV2, - for statistical reasons use A|| / D - D depolarisation factor, - exact formula used in analysis A.Magnon COMPASS week, PRAGUE August 1st-5 2005

high-pT hadron pairs: Q2<1GeV2 more difficult than large Q2 contributions from resolved photons - spin dependent structure of the photon perturbative part calculable non-perturbative part: - min/max VMD scenarios (Glück, Reya, Sieg) - tuning of intrinsic kT partons in the photon nucleon parameters - tuning of fragmentation functions - tuning of intrinsic kT in nucleon A.Magnon COMPASS week, PRAGUE August 1st-5 2005

Gluon polarisation, high pT pairs Q2>1GeV2 : 2002-2003 data Q2<1GeV2: A.Magnon COMPASS week, PRAGUE August 1st-5 2005

COMPASS week, PRAGUE August 1st-5 2005 Gluon polarisation G = 2.48 G = 0.62 G = 0.16 GRSV2000 NLO fits to g1 m2 = 3 Gev2 ΔG/G (xg ≈ 0.1) is small DG>1 disfavoured A.Magnon COMPASS week, PRAGUE August 1st-5 2005

Open charm: D’s from D*’s requiring the slow pion in D* → D πs→ K π πs D0 → K π π0 A.Magnon COMPASS week, PRAGUE August 1st-5 2005

Gluon polarisation, D0 & D* events 2002-2003 data DG/G = -1.08 +/- 0.73 <xg> = 0.15 +/- 0.08 A.Magnon COMPASS week, PRAGUE August 1st-5 2005

COMPASS week, PRAGUE August 1st-5 2005 Gluon polarisation G = 2.48 G = 0.62 G = 0.16 GRSV2000 NLO fits to g1 A.Magnon COMPASS week, PRAGUE August 1st-5 2005

Figure of Merit for open charm FoM 2002 – 2004 -> 2006 FoM(DG/G) s(DG/G)=1/FoM1/2 We work very hard to increase FoM A.Magnon COMPASS week, PRAGUE August 1st-5 2005

Figure of Merit for open charm FoM increase in 2006 (with upgrades): New COMPASS magnet: 1.3 Rich upgrade: 1.5 Ecal: 1.2 K below threshold: 1.1 100 days of beam: 1.3 -> (~ .9) total: 3.4 -> (~2.4) A.Magnon COMPASS week, PRAGUE August 1st-5 2005

Large Angle Spectrometer 2002-3-4-6 DC1 DC2 DC4 Straws Initial lay-out end 2002 downstream of SM2 ~ 200 mrd COMPASS PT solenoid Modified ..... ~ 70 mrd SMC solenoid Straws: 1 1/2 21/2 DCs: 3 A.Magnon COMPASS week, PRAGUE August 1st-5 2005

COMPASS Oxford Danfysik magnet OD magnet presently tested and instrumented in Saclay Some delays ... Magnet will be delivered to CERN in November A.Magnon COMPASS week, PRAGUE August 1st-5 2005

COMPASS week, PRAGUE August 1st-5 2005 COMPASS OD magnet 1st attempt to get uniform field (24.06): encouraging 100 ppm Request is ≤ 100 ppm A.Magnon COMPASS week, PRAGUE August 1st-5 2005

COMPASS week, PRAGUE August 1st-5 2005 RICH (PDs) upgrade in 2006 5 m 6 m 3 m Photon Detectors: CsI MWPC mirror wall vessel radiator: C4F10 A.Magnon COMPASS week, PRAGUE August 1st-5 2005

COMPASS week, PRAGUE August 1st-5 2005 RICH upgrade in 2006 central region ‘maPMT’: multi-anode PMTs lens system MAD4 preamp F1 TDCs, excellent time resolution outer region ‘APV’: keep CsI photodetector new readout based on APV chips good timing resolution ‘no’ DAQ dead time beam A.Magnon COMPASS week, PRAGUE August 1st-5 2005

COMPASS week, PRAGUE August 1st-5 2005 RICH maPMT elements tested in T11 beam approved by INFN in April, design of optics finished, PMs ordered (600) delivery schedule Q3 2005 till Jan 2006 ready spring 2006 Trieste, Turin + Bonn, Erlangen, Freiburg, Lisbon, Mainz, Prague (2) A.Magnon COMPASS week, PRAGUE August 1st-5 2005

COMPASS week, PRAGUE August 1st-5 2005 APV RICH project BORA CONNECTOR +3.7V, -3.7V, GND 10 PIN HE10CONNECTOR +5V, -5V, GND 10 PIN HE14CONNECTOR 4 Differential ADC Outputs RJ45 CONNECTOR CLK, TRIGGER, I2C + & - 1.25V Regulator POWER_MUX ( STRAPS ) & +/- 3.3V Regulators +/- 5V or +/-3.7V x 4 Fanout +/- 3.3 or 3.7 V 4 differential amplifiers J8 J7 J6 J5 J4 J3 J2 J1 J0 APV3 APV2 APV1 APV0 48 12 36 24 Figure 1 : Block-diagram of the new board dR, cm Trigger time x25ns R/O successfully tested during 2004 on the Rich installation and test Q1 /06 Design based on GEM & Si FEE Provides signal timing accuracy <200ns TU-Munich, Saclay A.Magnon COMPASS week, PRAGUE August 1st-5 2005

COMPASS week, PRAGUE August 1st-5 2005 Large drift chamber DC4 Chamber under construction by Saclay frames delivered assembly and test Q4/05-Q1/06 operational April 2006 A.Magnon COMPASS week, PRAGUE August 1st-5 2005

COMPASS week, PRAGUE August 1st-5 2005 ECAL1 Plan to equip entire ECAL1 for 2006 (Protvino) Also beneficial for open- charm D0 → K π π0 D*0 → D0 π0s A.Magnon COMPASS week, PRAGUE August 1st-5 2005

COMPASS week, PRAGUE August 1st-5 2005 SPS in 2006 Schedule prepared by SPS Coordinator & proposed by SPSC COMPASS - 2006 = 3440 h–> 142 days COMPASS – (2004)= 3120 h–> 130 days 110(m) 20(h) A.Magnon COMPASS week, PRAGUE August 1st-5 2005

COMPASS week, PRAGUE August 1st-5 2005 SPS in 2006 Schedule was not accepted by CERN RB New (draft) schedule: COMPASS – 2006’ 2728 h–> 113 days (not 142 d) restart of SPS etc … єSPS+BL ~ 0.7 or lower ~ 0.5 proposal year A.Magnon COMPASS week, PRAGUE August 1st-5 2005

COMPASS week, PRAGUE August 1st-5 2005 Conclusion muon programme was for ~2.5 years (SPS proposal-years) with 1.6 year of running, important physics results were obtained, also : - 3 physics papers (g1d, Collins/Sivers asym., penta-q search) - DG/G with remarkable precision from high pT low Q2 - s(DG/G) from D0 (0.73 -> 0.43 with 2004) A.Magnon COMPASS week, PRAGUE August 1st-5 2005

COMPASS week, PRAGUE August 1st-5 2005 Conclusion Ambitious objective for 2006 Complete proposed muon programme - get error on DG/G from charm close to error of proposal, - run both with deuteron & proton target 1/ successful equipment upgrades 2/ sufficient beam allocation from SPS (?) A.Magnon COMPASS week, PRAGUE August 1st-5 2005

COMPASS week, PRAGUE August 1st-5 2005 Additional slides A.Magnon COMPASS week, PRAGUE August 1st-5 2005

COMPASS week, PRAGUE August 1st-5 2005 s(h1d,h1p) vs acceptance COMPASS magnet SMC magnet A.Magnon COMPASS week, PRAGUE August 1st-5 2005

Resolved photon contributions PYTHIA e.g.: qq’→ qq’ A.Magnon COMPASS week, PRAGUE August 1st-5 2005

COMPASS week, PRAGUE August 1st-5 2005 Example: kT tuning nucleon photon systematic error - determined using 15 independent MC simulations - exploring the parameter space in kT of nucleon and photon fragmentation functions parton shower on/off, renormalisation scale A.Magnon COMPASS week, PRAGUE August 1st-5 2005

COMPASS week, PRAGUE August 1st-5 2005 Data versus MC excellent to good agreement for all kinematics variables let’s get A.Magnon COMPASS week, PRAGUE August 1st-5 2005

COMPASS week, PRAGUE August 1st-5 2005 Data versus MC excellent to good agreement for all kinematics variables let’s get A.Magnon COMPASS week, PRAGUE August 1st-5 2005

high-pT hadron pairs: Q2>1GeV2 xBj < 0.05, can neglect QCD Compton and LO LEPTO tuning à la SMC high-pT pT x p A.Magnon COMPASS week, PRAGUE August 1st-5 2005

COMPASS week, PRAGUE August 1st-5 2005 Open charm: MC studies pT z y AROMA Monte Carlo, PGF only background subtracted 2003 data (side bands) D’s indeed from PGF ? Data understood? good agreement data / MC hard z-distribution A.Magnon COMPASS week, PRAGUE August 1st-5 2005

COMPASS week, PRAGUE August 1st-5 2005 Open charm: MC studies aLL from one hadron from PGF reconstructed Correlation of generated and reconstructed aLL Analysis uses event weighting with aLL deduced from hadron kinematic variables A.Magnon COMPASS week, PRAGUE August 1st-5 2005

COMPASS week, PRAGUE August 1st-5 2005 RICH upgrade in 2006 A.Magnon COMPASS week, PRAGUE August 1st-5 2005