1 / 40

Prospects for GPD and TMD studies at the JLab Upgrade

Prospects for GPD and TMD studies at the JLab Upgrade. Volker D. Burkert* ) Jefferson Lab. Introduction JLab Upgrade and CLAS12 GPDs from DVCS and DVMP TMDs from SIDIS and SSA Summary. * ) Talk presented by H.Avakian. QCDN’06 Workshop, June 12-16, 2006, Rome. 3-D Scotty. z.

didina
Télécharger la présentation

Prospects for GPD and TMD studies at the JLab Upgrade

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Prospects for GPD and TMD studies at the JLab Upgrade Volker D. Burkert*) Jefferson Lab • Introduction • JLab Upgrade and CLAS12 • GPDs from DVCS and DVMP • TMDs from SIDIS and SSA • Summary *) Talk presented by H.Avakian QCDN’06 Workshop, June 12-16, 2006, Rome

  2. 3-D Scotty z 2-D Scotty z x y 1-D Scotty Water Calcium probablity Carbon x x GPDs, TMDs & PDFs This Workshop – GPDs, TMDs Deeply Inelastic Scattering, PDFs

  3. Wpu(x,k,r) “Parent” Wigner distributions d3r TMD TMD PDFs: fpu(x,kT),g1,f┴1T, h┴1L Measure momentum transfer to quark. Generalized PDFs (GPDs & TMDs) Probability to find a quark u in a nucleon P with a certain polarization in a position r and momentum k d2kT (FT) GPD GPDs: Hpu(x,x,t), Epu(x,x,t),… Measure momentum transfer to nucleon. • Provide complementary information on structure of nucleon • Studies require detection of multiparticle final states

  4. Add new hall CHL-2 Enhance equipment in existing halls E= 2.2, 4.4, 6.6, 8.8, 11 GeV Beam polarization Pe > 80% JLab Upgrade to 12 GeV Energy 12 GeV

  5. CLAS12 • Nearly full angle coverage for tracking and g, ndetection • High luminosity, 1035 cm-2s-1 • Concurrent measurement • of deeply virtual exclusive, • semi-inclusive, and inclusive • processes. EC Cerenkov Drift Chambers TOF Cerenkov Torus Central Detector Beamline IEC Design luminosity = 1035cm-2s-1

  6. 5m CLAS12 Beamline

  7. CLAS 12- Expected Performance Forward Detector Central Detector Angular coverage: Tracks (inbending) 8o - 40o 40o - 135o Tracks (outbending) 5o - 40o 40o - 135o Photons 2o - 40o 40o - 135o Track resolution: dp (GeV/c) 0.003p + 0.001p2 dpT=0.03pT dq (mr) < 1 (>2.5 GeV/c) 8 (1 GeV/c) df (mr) < 3 (> 2.5 GeV/c) 2 (1 GeV/c) Photon detection: Energy range > 150 MeV > 60 MeV dE/E 0.09(EC)/0.04(IEC) 0.06 (1 GeV) dq (mr) 4 (1 GeV) 15 (1 GeV) Neutron detection: heff 0.5 (EC), 0.1 (TOF) 0.04 (TOF) Particle id: e/p >>1000 ( < 5 GeV/c) - >100 ( > 5 GeV/c) - p/K (4s) < 3 GeV/c (TOF) 0.65 GeV/c 3 - 10 GeV/c (CC) p/p (4s) < 5 GeV/c (TOF) 1.2 GeV/c 3 - 10 GeV/c (CC) K/p(4s) < 3.5 GeV/c (TOF) 0.9 GeV/c

  8. H1, ZEUS Deeply Virtual Exclusive Processes - Kinematics Coverage of the 12 GeV Upgrade H1, ZEUS 27 GeV 11 GeV 11 GeV 200 GeV JLab Upgrade JLab @ 12 GeV COMPASS W = 2 GeV HERMES Study of high xB domain requires high luminosity 0.7

  9. GPDs – Flavor separation DVMP DVCS long. only hard gluon hard vertices M = r0/r+ select H, E, for u/d flavors M = p, h, K select H, E Photons cannot separate u/d quark contributions.

  10. ep egp Q2 > 2.5 GeV2 Central Detector Forward Detector ep ep+X Acceptance for DVCS, SIDIS qg xB = 0.35 EC IEC Q2

  11. ALU DVCS/BH- Beam Asymmetry Ee = 11 GeV With large acceptance, measure large Q2, xB, t ranges simultaneously. A(Q2,xB,t) Ds(Q2,xB,t) s(Q2,xB,t)

  12. Ee = 11 GeV Q2=5.5GeV2 xB = 0.35 -t = 0.25 GeV2 CLAS12- DVCS/BH- Beam Asymmetry Luminosity = 720fb-1

  13. CLAS12- DVCS/BH Beam Asymmetry e p epg E = 11 GeV DsLU~sinfIm{F1H+..}df Selected Kinematics L = 1x1035 T = 2000 hrs DQ2 = 1 GeV2 Dx = 0.05

  14. Q2=3.5 GeV2 bval=bsea=1 MRST02 NNLO distribution • Other kinematics measured concurrently GPDHfrom projected DVCS ALU data p

  15. Unphysical JLab12: Hall A with 3, 4, 5 pass beam Absolute measurements: d(e=±1) 250K events/setup H(e,e’)p Twist 2 & Twist 3 separation. Im{DVCS*BH}+DVCS2 Re{DVCS*BH} +’DVCS2 100 days

  16. L = 2x1035 cm-2s-1 T = 1000 hrs DQ2 = 1GeV2 Dx = 0.05 E = 11 GeV CLAS12-DVCS/BH Target Asymmetry e p epg Longitudinally polarized target ~ Ds~sinfIm{F1H+x(F1+F2)H...}df Provide precision measurements of polarized GPD

  17. CLAS12-DVCS/BH Target Asymmetry Sample kinematics e p epg E = 11 GeV Q2=2.2 GeV2, xB = 0.25, -t = 0.5GeV2 Transverse polarized target Ds ~ sinfIm{k1(F2H– F1E) +…}df AUTx Target polarization in the scattering plane AUTy Target polarization perpendicular to the scattering plane • Asymmetries highly sensitive to the u-quark contributions to the proton spin.

  18. xB = 0.3-0.4 -t = 0.2-0.3GeV2 sL sT Other bins measured concurrently CLAS12– L/T Separationep epro (p+p-) Projections for 11 GeV (sample kinematics) • Test of Bjorken scaling • Power corrections?

  19. Q2=5 GeV2 A~ Hu - Hd B ~ Eu - Ed r+ Exclusiver0production on transverse target 2 D (Im(AB*))/p T AUT = - |A|2(1-x2) - |B|2(x2+t/4m2) - Re(AB*)2x2 A ~ 2Hu + Hd r0 B ~ 2Eu + Ed r0 Eu, Edprobes the orbital motion of quarks. B K. Goeke, M.V. Polyakov, M. Vanderhaeghen, 2001

  20. SIDIS at leading twist e Boer e p Mulders e p transversity Sivers Off-diagonal PDFs vanish if quarks only in s-state! In addition T-odd PDFs require FSI(Brodsky et al., Collins, Ji et al. 2002)

  21. PT-dependence of beam SSA In the perturbative limit 1/PT behavior expected EIC 2.0 Perturbative region Non-perturbative TMD PT-dependence of azimuthal moments allows studies of transition from non-perturbative to perturbative description (Unified theory by Ji et al).

  22. sin(f-fs) (P /M)AUT T SIDIS Azimuthal Asymmetry - Sivers effect • Probes orbital angular momentum of quarks by measuring the imaginary part ofs-p-wave interference in the amplitude. • Hadrons from struck quark have the same sign SSA • Opposite effect in target fragmentation T

  23. CLAS12- Sivers function from AUT (p0) Efremov et al (large xB behavior of f1T from GPD E) In large Nc limit: F1T=∑qeq2f1T┴q f1Tu = -f1Td CLAS12 projected CLAS12 projected xB xB

  24. Sivers effect in the target fragmentation xF>0 (current fragmentation) xF<0 (target fragmentation) xF- momentum in the CM frame Wide kinematic coverage of CLAS12 allows studies of hadronization in the target fragmentation region

  25. sin(f+fs) sUT~ k h1H1 T Azimuthal Asymmetry - Collins Effect • Access to transversity distribution and fragmentation of polarized quarks • Unfavored SSA with opposite sign • No effect in target fragmentation

  26. T T sUL ~ k h1LH1 KM Collins Effect and Kotzinian-Mulders Asymmetry Measures the Collins fragmentation with longitudinally polarized target. Access to the real part of s-p wave interference amplitudes.

  27. 12 GeV Upgrade - Milestones • June 2006 Annual Review of Project Progress • August 2006 JLab PAC 30 • First review of 12 GeV proposals – “first 5 years of experiments” • Key first step in identifying the research interests and significant contributions of international and other non-DOE collaborators • October 2006 – start Project Engineering & Design (PED) • 12 GeV is on track for Construction Approval in Sept 2008

  28. Summary • The JLab 12 GeV Upgrade is essential for the study of nucleon structure in the valence region with high precision: • - deeply virtual exclusive processes (DVCS, DVMP) • - semi-inclusive meson production with polarized beam • and polarized targets • Provide new and deeper insight into • - quark orbital angular momentum contributions • to the nucleon spin • - 3D structure of the nucleon’s interior and correlations • - quark flavor polarization • - ….. • CLAS12 will be world wide the only full acceptance, general purpose detector for high luminosity electron scattering experiments, and is essential for the GPD/TMD program.

  29. New Collaborators are welcome!

  30. Additional Slides

  31. CLAS12

  32. CLAS12– Central Detector (B0 = 5T) TOF light-guide Cryostat vacuum jacket Space for e.m. calorimeter SiliconTracker Main coil Compensation coil Central TOF

  33. JLab Upgrade -CLAS12 Luminosity > 1035cm-2s-1 Tracking - Drift Chambers, SVT Particle id - p/K/p ToF, - Cerenkov’s - g/p0 Calorimetry Forward Detector Central Detector

  34. 2004-2005 Conceptual Design (CDR) 2004-2008 Research and Development (R&D) 2006 Advanced Conceptual Design (ACD) 2007-2009 Project Engineering & Design (PED) 2008 Long Lead Procurement 2008-2012 Construction 2012-2013 Pre-Ops (beam commissioning) 12 GeV Upgrade: Project Critical Decision–1 Approval in February 2006 12 GeV Upgrade included in DOE 5-Year Business Plan in March 2006 NOTE – schedule shown per Feb 2006 CD-1 Documents, new funding profile received in April, update of project plan in progress

  35. Near Term: June 2006 Annual Review of Project Progress Focus on progress in last year, and plans for CD-2B Performance Baseline review next year CD-2B Approval anticipated for September 2007 August 2006 JLab PAC 30 First review of 12 GeV proposals – “commissioning experiments” Spokespersons make commitments to construction of equipment Key first step in identifying the research interests and significant contributions of international and other non-DOE collaborators October 2006 – start Project Engineering & Design (PED) 12 GeV is on track for CD-2 in Sept 2007 and CD-3 in Sept 2008 12 GeV Upgrade: Status

  36. Azimuthal Asymmetry – Sivers Effect Originates in the quark distribution. It is measured in the azimuthal asymmetry with transverse polarized target. sin(f-fs) f1TD1 T AUT ~ k Requires: non-trivial phase from the FSI + interference between different helicity states (S. Brodsky)

  37. T T sUL ~ (1-y) h1LH1 KM Collins Effect and Kotzinian-Mulders Asymmetry Measures the Collins fragmentation with longitudinally polarized target. Access to the real part of s-p wave interference amplitudes.

  38. ` CLAS12-L(1115) Polarization E = 11 GeV ep eL(pp-)X (SIDIS) K K*(892)

  39. e 1 Λ p 2 L polarization in the target fragmentation e’

  40. 1 1 ∫ ∫ dxxHq(x,x,t) = Hq(t) + x2Dq(t) dxxEq(x,x,t) = Eq(t) - x2Dq(t) -1 -1 Link to the Quark Structureof the Nucleon finite t Distribution of the forces on quarks in transverse space. Quark distributions in transverse space, and orbital angular momentum distribution.

More Related