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

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

A.MagnonCOMPASS week, PRAGUE August 1 st Report on the SPSC Villars Meeting September John Dainton University of Liverpool, GB (on behalf of the SPSC) Villars 2004

A.MagnonCOMPASS week, PRAGUE August 1 st Report on the SPSC Villars Meeting September John Dainton University of Liverpool, GB (on behalf of the SPSC) 1.Framework 2.Machines and Beams 3.Heavy Ions 4.Neutrinos 5.Soft and Hard Protons 6.Antiproton Physics 7.Flavour Physics 8.Other Topics 9.Summary Villars 2004 COMPASS Report on the SPSC Villars meeting by John Dainton, University of Liverpool (CERN-SPSC SPSC-M-730 February 28 th 2005, available on Web)

A.MagnonCOMPASS week, PRAGUE August 1 st 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 COMPASS Collaboration

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

A.MagnonCOMPASS week, PRAGUE August 1 st SM1 dipole SM2 dipole Polarised Target HCAL1 Muon-filter1,MW1 SPS 160 GeV  /spill Micromegas,DC,SciFi Gems,SciFi,DCs,straws MWPC Gems Scifi trigger-hodoscopes Silicon Spectrometer > 2004 RICH_1Gem_11 ECAL2,HCAL2 straws,MWPC,Gems,SciFi straws Muon-filter2,MW2 DW45 SciFi Veto

A.MagnonCOMPASS week, PRAGUE August 1 st COMPASS objectives Original programme set for about 5 years (1) of running at 150 days/year with 14.4s supercyle and  SPS = 80%. i.e. 7.2  10 5 spills/year i.e PoT/year (2  10 8  /spill) (1) HMC (4 years) - CHEOPS (2 years)

A.MagnonCOMPASS week, PRAGUE August 1 st Beam (1) 106days 90d 110d є SPS+BL (2) Preparation ~30d 7d 3d є Spectro (3) Data taking (4) 44d 39d 61d muon (L/T) 33d/11d 30d/9d 47d/14d Data taking 2002 – 2004 (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 d 4d 15d hadron

A.MagnonCOMPASS week, PRAGUE August 1 st Data taking muon: > 11.6  10 5 spills request: 7.2  10 5 spills/year  2.5 (proposal-year) Pilot hadron run: > ~ 0.7  10 5 spills We got ~ 1.6 (proposal-year)

A.MagnonCOMPASS week, PRAGUE August 1 st Highlights (SPSC71 status report) : - g 1 - transversity -  polarisation -  G/G from high p T hadron pairs -  G/G from open-charm - more … Physics results

A.MagnonCOMPASS week, PRAGUE August 1 st most precise measurement for < x < 0.03 PLB 612 (2005) 154 new NLO QCD fit, precision of a 0 improves factor 2 ( = 4 GeV 2 ) g 1 of the deuteron data

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

A.MagnonCOMPASS week, PRAGUE August 1 st 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 Quark polarimeters

A.MagnonCOMPASS week, PRAGUE August 1 st 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. M. Anselmino et al. hep-ph/ (including HERMES Prel. Results shown at DIS05)

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

A.MagnonCOMPASS week, PRAGUE August 1 st Expected accuracy for Collins asymmetries

A.MagnonCOMPASS week, PRAGUE August 1 st Strategies to suppress background: 1) Open charm production: q = c unique, no background charm fragmentation, 1.2 D 0 per event D 0 -> K - π + (BR 4%), D * + (~20%) -> D 0 π + 2) High-p T hadron pair production: q=u,d,s background from non PGF events & resolved  pQCD scale set by: 1) ŝ > 4m c 2 or 2) ŝ > (p t1 +p t2 ) 2 ΔG/G from Photon-Gluon Fusion Photon Gluon Fusion LOW STAT. HIGH STAT. Needed since Q 2 ~ 0

A.MagnonCOMPASS week, PRAGUE August 1 st a LL : calculable partonic asymmetries R : Monte-Carlo (Lepto/Phytia depending on Q 2 ) Photon Gluon FusionLeading order ProcessQCD-Compton e,  N measured h1h1 h2h2 ΔG/G from high-p T hadron pair

A.MagnonCOMPASS week, PRAGUE August 1 st Q 2 < 1GeV evts Q 2 > 1GeV evts 2002 and 2003 data - p T,1, p T,2 > 0.7 GeV, p 2 T,1 + p 2 T,2 > 2.5 GeV 2, - for statistical reasons use A || / D - D depolarisation factor, - exact formula used in analysis high-p T hadron pairs Q 2 1GeV 2

A.MagnonCOMPASS week, PRAGUE August 1 st more difficult than large Q 2 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 k T partons in the photon nucleon parameters - tuning of fragmentation functions - tuning of intrinsic k T in nucleon high-p T hadron pairs: Q 2 <1GeV 2

A.MagnonCOMPASS week, PRAGUE August 1 st Q 2 >1GeV 2 : Q 2 <1GeV 2 : Gluon polarisation, high p T pairs data

A.MagnonCOMPASS week, PRAGUE August 1 st  G = 2.48  G = 0.62  G = 0.16 Gluon polarisation ΔG/G (x g ≈ 0.1) is small GRSV2000 NLO fits to g 1  2 = 3 Gev 2  G>1 disfavoured

A.MagnonCOMPASS week, PRAGUE August 1 st Open charm: D’s from D*’s requiring the slow pion in D* → D π s → K π π s D 0 → K π π 0

A.MagnonCOMPASS week, PRAGUE August 1 st Gluon polarisation, D 0 & D * events data  G/G = / = /- 0.08

A.MagnonCOMPASS week, PRAGUE August 1 st  G = 2.48  G = 0.62  G = 0.16 Gluon polarisation GRSV2000 NLO fits to g 1

A.MagnonCOMPASS week, PRAGUE August 1 st – > 2006 FoM(  G/G)  G/G)=1/FoM 1/2 We work very hard to increase FoM FoM Figure of Merit for open charm

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

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

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

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

A.MagnonCOMPASS week, PRAGUE August 1 st RICH (PDs) upgrade in m 6 m 3 m PhotonDetectors: CsI MWPC mirrorwall vessel radiator: C 4 F 10

A.MagnonCOMPASS week, PRAGUE August 1 st 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 RICH upgrade in 2006

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

A.MagnonCOMPASS week, PRAGUE August 1 st APV RICH project R/O successfully tested during 2004 on the Rich installation and test Q1 /06 Trigger time x25ns dR, cm TU-Munich, Saclay BORA CONNECTO R +3.7V, -3.7V, GND 10 PIN HE10CONNE CTOR +5V, -5V, GND 10 PIN HE14CONNE CTOR 4 Differential ADC Outputs RJ45 CONNECT OR CLK, TRIGGER, I2C + & V Regul ator + & V Regul ator + & V Regul ator + & V Regul ator POWER_MUX ( STRAPS ) & +/- 3.3V Regulators +/- 5V or +/-3.7V x 4 Fano ut +/- 3.3 or 3.7 V 4 differential amplifiers J8J7J6J5J4J3J2J1J0 APV3APV2APV1APV Figure 1 : Block-diagram of the new board Design based on GEM & Si FEE Provides signal timing accuracy <200ns

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

A.MagnonCOMPASS week, PRAGUE August 1 st ECAL1 Plan to equip entire ECAL1 for 2006 (Protvino) Also beneficial for open- charm D 0 → K π π 0 D *0 → D 0 π 0 s

A.MagnonCOMPASS week, PRAGUE August 1 st SPS in 2006 Schedule prepared by SPS Coordinator & proposed by SPSC COMPASS = 3440 h–> 142 days COMPASS – (2004)= 3120 h–> 130 days 110(  20(h)

A.MagnonCOMPASS week, PRAGUE August 1 st 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 … є SPS+BL ~ 0.7 or lower ~ 0.5 proposal year

A.MagnonCOMPASS week, PRAGUE August 1 st 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) -  G/G with remarkable precision from high p T low Q 2 -  G/G) from D 0 (0.73 -> 0.43 with 2004)

A.MagnonCOMPASS week, PRAGUE August 1 st Conclusion Ambitious objective for 2006 Complete proposed muon programme - get error on  G/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.MagnonCOMPASS week, PRAGUE August 1 st Additional slides

A.MagnonCOMPASS week, PRAGUE August 1 st  h 1 d,h 1 p) vs acceptance SMC magnet COMPASS magnet

A.MagnonCOMPASS week, PRAGUE August 1 st Resolved photon contributions e.g.: qq’→ qq’ PYTHIA

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

A.MagnonCOMPASS week, PRAGUE August 1 st Data versus MC excellent to good agreement for all kinematics variables let’s get

A.MagnonCOMPASS week, PRAGUE August 1 st Data versus MC excellent to good agreement for all kinematics variables let’s get

A.MagnonCOMPASS week, PRAGUE August 1 st x Bj < 0.05, can neglect QCD Compton and LO LEPTO tuning à la SMC high-p T xpTpT p high-p T hadron pairs: Q 2 >1GeV 2

A.MagnonCOMPASS week, PRAGUE August 1 st Open charm: MC studies 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 z pTpT y

A.MagnonCOMPASS week, PRAGUE August 1 st Open charm: MC studies a LL from one hadron from PGF reconstructed Correlation of generated and reconstructed a LL Analysis uses event weighting with a LL deduced from hadron kinematic variables

A.MagnonCOMPASS week, PRAGUE August 1 st RICH upgrade in 2006