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Future Physics using Hadron Beams with

Future Physics using Hadron Beams with. COMPASS. Stephan Paul TU- München For the COMPASS collaboration. Outline. Future Physics (discussed in the COMPASS workshop 2002)  PT-Tests Light Meson Spectroscopy Double Charm New ideas Excited Charmed Hadrons ( not in proposal )

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Future Physics using Hadron Beams with

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  1. Future Physics using Hadron Beams with COMPASS Stephan Paul TU-München For the COMPASS collaboration

  2. Outline • Future Physics (discussed in the COMPASS workshop 2002) • PT-Tests • Light Meson Spectroscopy • Double Charm • New ideas • Excited Charmed Hadrons (not in proposal) • Polarized Drell-Yan (not in proposal) • Summary of Requirements • Experimental set-up • Beam conditions COMPASS - Future Physics

  3. Physics of COMPASS Deep Inelastic Polarized Lepton Scattering Spectroscopy Low Q2 Scattering Structure of hadrons • Probe nucleons at high Q2 • Quasi free quarks and gluons • Understanding of the nucleon’s properties from the dynamics of its constituents • Gluons and the spin of the nucleon • Flavour decomposition • Parton correlations • ‘wave function’ of the constituents • Use semi-inclusive or exclusive DIS with particle ID • Probe the structure of hadrons at low Q2 • Mass spectrum • Confinement • Gluonic excitations • Structure of hadrons (qq-mesons, hybrids, qqqq-molecules) • Heavy light systems • Probe QCD at very low Q2 • Understanding of the strong interaction at large distances Effective field theories - cPT COMPASS - Future Physics

  4. Present Status - Setup SAS Muon filter 2 MWPCs ECal2 & HCal2 LAS SM2 Muon filter 1 ECal1 & HCal1 GEM & MWPCs SciFi RICH Drift. Ch. SM1 Silicon SciFi GEM & MWPCs Scintillating fibers GEM & Straws Beam Micromegas Polarized target 2002 run: 160 GeV µ+ beam 2 . 108 µ/spill (4.8 s) COMPASS - Future Physics 2 stage spectrometer: LAS, SAS Tracking: VSAT, SAT, LAT Calorimetry:Ecal1,Hcal1,Ecal2,Hcal2 PID: RICH-1, m-wall1, m-wall2 Polarised Target

  5. The COMPASS Workshop – September 2002 • 20 Talks • 7 Outside guests • 6 Theory Talks COMPASS - Future Physics

  6. PT-Tests • Physics • PT is low energy effective field theory (replacing QCD) • Crucial for understanding low energy phenomena COMPASS - Future Physics and low energy constants to be determined by experiment • important processes to be studied at COMPASS (Gasser)

  7. PT-Measurements - COMPASS • Use inverse kinematics COMPTON scattering (Primakoff) • use p/K beams on heavy target • CEDAR’s for beam particle ID • Silicon telescope around target • target veto box COMPASS - Future Physics

  8. Light Meson Spectroscopy • Physics • Search for gluonic excitations (‘glueballs’) • Search for exotics (‘hybrids’) • Reactions • Peripheral Reactions • Diffractive • Primakoff (g-production) • Central Production • Glueball filter • Setup’s COMPASS - Future Physics

  9. Light Meson Spectroscopy – Physics • Predictions for ‘pure’ glueballs by lattice calculations (quenched) • Lightest glueball (JPC=0++) with mass in the range1.45-1.75 GeV • At present three states in theglueball mass range are: • f0(1370) • f0(1500) • f0(1710) • Data stem from • Crystal barrel (pp annihilation) • WA102 (pp central production) • BNL (p - diffractive production.. hybrids) • VES (p- diffractive production .. hybrids) • Analysis ofglueball-qq mixing necessary • Use decay pattern • Decay width • Mixing of glueball |G>, strange |ss> and non-strange |uu+dd> states COMPASS - Future Physics The spectrum of glueballs in pure glue LGT (Morningstar, Peardon).

  10. Diffractive and Photoproduction • Diffractive production • Proceeds via Pomeron-exchange (Regge trajectory) • Coupling of projectile with 2++ object • Clean low multiplicity events • Use p and K beams to explore flavour space • Production rate estimate: • 2.5•107/spill • 40cm hydrogen target (solid target possible) • ~ 2500/dayhp -p+p-p0 p - • Photo-Production • Proceeds via g-exchange • Use coupling to r-channel (use VMD) • Advantage: hybrids may have larger radiative width • Suppression of background production of other partial waves • Suppression of meson exchange background • ~ 12000/dayhp-gg p with (G(p1 pr) ~ 60 MeV • Simultaneous measurements possible • Separation of different processes via t-cut (dt ~ 10-4) A A COMPASS - Future Physics

  11. Central Production fast slow • Goal: Pomeron-Pomeron scattering • Glue rich environment (no open flavour) • Background from Regge exchange • WA102 has observed: • f0(1300), f0(1500), f0(1710), f2(1900) • Kinematic correlation with DpT of pslowpfast with DpT<0.2 GeV enhancing ‘glue rich’candidates • Rate estimates • 2.5 • 107/spill and prod ~ 3 b and40cm LH2 • f0(1500) events: • With ECAL 1 and small ECAL 2: 20 / hour • With ECAL 1 and ECAL 2 : 40 / hour • With ECAL 0, ECAL 1 and ECAL 2: 120 / hour • h  2gandh p0pp • For radiation hard ECAL 2 – rates up by factor 3 COMPASS - Future Physics

  12. Triggering on Glue ? ... See WA102 • LL and LR triggers: • LL: dpT large • LR: dpT small COMPASS - Future Physics f0(980) r0(770) f2(1270) Ordinary mesons dpT: small...........................large < 0.2 GeV/c > 0.5 GeV/c

  13. Light Meson Spectroscopy - COMPASS COMPASS - Future Physics • Full setup for central production • For diffractive and Primakoff – WAD and ECAL1 not needed

  14. Excited Charmed Mesons cs- states • New spectroscopy of narrow excited D and Ds states • FOCUS, BaBar, Belle, CLEO and SELEX COMPASS - Future Physics ExcitedDs 670 MeV excitation energy ExcitedD Observations in agreement with HQET

  15. Excited Charmed Baryons Narrow states have also been observed for excited chamedbaryons COMPASS - Future Physics ExcitedLc Summary charmed baryons

  16. Excited Charm • Counting rates • SELEX: 540 Dscandidates in KKp final state (produced by S- beam) • 42 candidates for Ds+(2632) Ds • A total of 10K D0 decays observed (1/50 of FOCUS sample) • COMPASS goal: • 5·106 D-decays • Assume 105 Dsdecays .... (see E791 experiment for Ds/D) • Good perspectives for D and Ds resonance hunting • Running time... 1years (possibly 2 yrs.. see proposal which aimed at 107 D-decays) COMPASS - Future Physics

  17. Doubly Charmed Baryons excited state ground state Phys. Rev Lett. 89 (2002) Xcc++ Xcc*+ Xcc+ • Physics and Status • Spectroscopy • System in ground state is B-like separate slow motion of heavy and fast motion of light quarks • Excitation via c-c excitation (charmonium like) tests dynamics of confinement • Mass spectrum calculable rather reliably • First evidence for cc-system by SELEX COMPASS - Future Physics 2004 • Problems: Cross section very high (50% of Lc+) • Isospin splitting too large (60 MeV)

  18. Doubly Charmed Baryons • Lifetimes • Decay of baryons goverened by three (partly) long-distance processes (W-exchange, spectator decay, quark interference) • ‘Good’ description of decay pattern of baryons/mesons • Problem so far: Lb lifetime ‘too short’ • Predictions with this scheme for Xcc states (different combination of processes) • First observation by SELEX t(Xcc +) ~ 30 fs COMPASS - Future Physics • Prediction: • (Xcc +) t(Wcc +) «t(Xcc ++) with t(Xcc +)~ 400fs

  19. Doubly Charmed Baryons in COMPASS SM1 • Use 270 GeV proton beam • Vertex detector system • Trigger • Processing: Frontend, ROB, CPU-farm • Selex yield(50% of all Lc from Xcc) (sXcc~ 2mb)50 • 106 (ccq) produced 10-17k events • Incoherent production: assuming sXcc~ stot• (10-3)2 ~2 nb 90-170 events COMPASS - Future Physics

  20. Transverse Structure Functions (Drell-Yan) Twist-2 PDFs COMPASS - Future Physics

  21. Transverse Structure Functions via Drell-Yan Kinematics COMPASS - Future Physics Spectrum

  22. Observed asymmetries in Drell-Yan Di-Lepton Rest Frame E615 @ Fermilab -N  +-X @ 252 GeV/c COMPASS - Future Physics -0.6 < cos < 0.6 4 < M < 8.5 GeV/c2

  23. Drell-Yan: hp l+l- + X Initial state interactions – non zero unpolarized hadrons ! NLO pQCD: λ 1,   0, υ 0 Experimental data [1]: υ 30 % [1]J.S.Conway et al., Phys. Rev. D39(1989)92. COMPASS - Future Physics υinvolves transverse spin effects at leading twist [2]: cos2φ contribution to angular distribution provides: [2]D. Boer et al., Phys. Rev. D60(1999)014012, D.Boer, S.Brodsky and D.S.Hwang Phys.Rev.D67(2003)054003.

  24. Drell-Yan Asymmetries: hp l+l- + X λ 1,   0 COMPASS - Future Physics Unpolarised beam and polarized target is a powerful tool to investigate кT dependence of QDF D. Boer et al., Phys. Rev. D60(1999)014012, D. Boer et al Phys.Rev.D67,054003,2003

  25. Transverse Structure Functions (Drell-Yan) Phasespace  = const: hyperbolae xF = const: diagonal COMPASS - Future Physics 15 GeV/c PANDA (GSI) 30 GeV/c ASSIA (GSI) 40 GeV/c COMPASS (CERN)

  26. Transverse Structure Functions (Drell-Yan) Drell-Yan Counting rate: Beam intensity : 108- s-1 • Target: 15 g/cm2 LD or • Luminosity: L = • Cross section value = 0.3 nb/nucl • Acceptance • Expected rate: R = events/s • TThus 0.15 events/spill (4000 spills/day) 600 events/day COMPASS - Future Physics Total expected statistics: (SPS eff = 80%) 120 days - 50.000 events

  27. Requirements COMPASS - Future Physics

  28. Set-ups for new Measurements COMPASS - Future Physics

  29. Hardware Requirements - Summary COMPASS - Future Physics

  30. Requirements – Set-up • Hardware-Additions • ECAL 0 (for DVCS) • Frame new • Pb/Scintillator detector to be refurbished • Readout new • ECAL 1 • Frame construction completed • Lead glass detector refurbished • Readout new and partially existing • ECAL 2 • Frame new • Lead glass detector existing • 800 radiation hard calorimeter modules new • Readout existing (in part) • Silicon detectors • Radiation hard cryogenic detectors (in preparation for 2004) • Additional detectors for telescope new (2 more stations) • CEDAR’s • Exisiting (refurbishing to be done) COMPASS - Future Physics

  31. Requirements – Set-up • RICH 2 new… not mandatory • Design consideration completed… however, unlikely to be built • Target Recoil Detectors • Small system for central production refurbishment completed (RO new) • Hydrogen targets • 40cm target for central production existing but to be refurbished • Improved Tracking • BMS (on the way) • Silicon telescope with 8-10 detectors (20 views) …(6 detectors existing) • LAT downstream SM2 (useful) • Trigger Hodoscopes (in LAS) • DAQ • High Trigger Rate compatibility new (in preparation) • Data Filter new (prototype running) COMPASS - Future Physics

  32. Requirements - Beam • High duty cycle beam (5 s/16.8 s) • Proton intensities/energy • Hadron beam p/K, p • 150-270 GeV/c (400 GeV would be better for charm) • secondary beam intensities: 2•108/spill • Proton beam intensities 1011/spill • Proton beam energy (350-400 GeV/c) • Muon beam m • 100-190 GeV/c • Secondary beam intensity: 2•108/spill • Proton beam intensity 1.2•1013/spill • Proton beam energy (400-450 GeV/c) • Running time of 150 days/year (as in proposal!) • 2006-2010 COMPASS - Future Physics

  33. Summary • Exciting physics program in hadron physics for 2006 onwards • All major physics issues addressed • Hadron beam • cPT-Tests • Spectroscopy (three different production techniques in one experiment) • Drell-Yan with polarized target (under study) • Muon beam • DVCS door opened (see other talks) • Complete measurements in DIS and SIDIS (see other talks) • Obsolete subjects (described in original proposal) • Semileptonic decays of charmed mesons (CLEO-C, Belle, BaBar) • Leptonic decays of charmed mesons (CLEO-C, BES) • Hardware additions necessary • Partly existing • Partly to be setup COMPASS - Future Physics

  34. PT-Tests - Polarizability • gp gp (Compton scattering) • Expansion in terms of pg– quadratic term contains polarizabilities • Polarizabilities explore loop effects and test consistency of chiral expansion as pp-scattering length • From experiment (Serpukhov) 1 loop 2 loop COMPASS - Future Physics a+ = 0, a- ~ LEC ( = 0 at 1-loop)

  35. PT-Tests - COMPASS • Measure independently • Good systematics • Different target nuclei (get Z2-dependence) • Flat acceptance in t • Large angular acceptance in g-scattering angle • Beam • 190 GeV/c • 2•107/spill • 30days: 1.2 • 107 Primakoff events (1000-times existing statistics) • Better resolution dap ~ 0.4 10-4 fm3 (stheory) • Get Kaon polarizability: (~300 times less events than for p) • Lower beam flux • Lower cross section daK ~ 0.6 10-4 fm3 COMPASS - Future Physics

  36. PT-Tests - Anomaly • Anomaly: Symmetry of Langrangian disappearing by quantization • How to measure g  3p? • Antipov et al in Serpukhov • F3p = 12.9 0.9  0.5 GeV-3 • COMPASS • 500 times existing statistics in 30 days Fp F3p p0-decay g-3p-coupling COMPASS - Future Physics F3p = Fp/ (4pa)1/2fp2 F3p = e Nc/ 12 p2 fp= 9.7  0.2GeV-3

  37. Requirements - Resources • Finances • Already ‘funded’ • ECAL electronics (ECAL 1 + ECAL 2) • Additional Silicon detectors • Part of data-filter • Tracking backups (straws, beam momentum station, GEM) • In the queue • LAT (‘RICH wall’) • RICH 2 • EU-project application • RICH 2 • DAQ development • To be funded • ECAL 0 • Target Recoil detector (DVCS) • Larger tracking downstream SM2 (not mandatory) • Improved trigger hodoscopes • DAQ upgrade • LH2 targets COMPASS - Future Physics

  38. Transverse Structure Functions (Drell-Yan) COMPASS spectrometer: • New polarized target (wide acceptance) • GEM, MICROMEGA detectors small angle • MWPC, STRAW detectors large angle • vertex resolution • Iarocci like tubes or large area drift chambers → Id • Powerful E-calorimetry COMPASS - Future Physics Trigger to be improved: • LARGE AREA HODOSCOPEs

  39. Requirements - Resources • Man power • All groups ready to continue for full programme • Additional groups (e.g. Lisbon) joined • Other groups have expressed possible interest • Increasing interest among young physicists • MoU • Addendum to memorandum of understandingin preparation COMPASS - Future Physics

  40. Quark Distribution-Functions for Hadrons • For q collinear with hadron ( k = xP) Three distribution functions: • f(x): probability of finding a quark carrying a fraction x of the • longitudinal momentum P of the hadron (regardless of polarization) COMPASS - Future Physics In longitudinally polarized hadrons, f(x) = number density of quarks with helicity  1 • f(x) = f+(x) – f-(x)f(x) = f+(x) + f-(x) In transversely polarized hadron, f()(x) = density of quarks with parallel (antiparallel) polarization • Tf(x) = f(x) – f(x)

  41. New distribution functions f(x)  f(x,k) • For q non collinear with hadron ( k = xP + k) • f1(x,k2) • g1(x,k2) • h1(x,k2) integrating on k2  f(x), f(x), Tf(x) COMPASS - Future Physics • g1T(x,k2) • h1L(x,k2) • h1T(x,k2) integrating on k2:F1T(x,k2) 0 relaxing time reversal invariance • f1T(x,k2) for unpolarized quark in transversally polarized hadron • h1(x,k2) for transversally polarized quark in unpolarized hadron

  42. Doubly Charmed Baryons - Perspectives • Resolution • Mass resolution Xcc: 13 MeV • Lifetime: • Production • 108p/spill on 2% target – 100 effective days • Acceptance xF > -0.1 • Total acceptance • efficiency: 0.8% • Branching ration Br(ccq) • Br(cqq) = 6% • Vertexing and detector efficiency: 40-70% • Selex yield (50% of all Lc from Xcc) (sXcc~ 2mb) • 50 • 106 (ccq) produced ~ 10-17k events • Incoherent production: assuming sXcc~ stot• (10-3)2~2 nb 90-170 events COMPASS - Future Physics

  43. The COMPASS Collaboration Bielefeld, Bochum, Bonn (ISKP), Bonn (PI), Burdwan and Calcutta, CERN, Dubna (LPP and LNP), Erlangen, Freiburg, Heidelberg, (Helsinki), Mainz, Lissabon, Moscow (INR), Moscow (LPI), München (LMU), München (Technische Universität), (Nagoya), Prague, Protvino, Saclay, Tel Aviv, Torino (University and INFN), Trieste (University and INFN), Warsaw (SINS), Warsaw (TU) More than 220 Physicists from 26 Institutes COMPASS - Future Physics

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