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NUCLEON STRUCTURE OVERVIEW

NUCLEON STRUCTURE OVERVIEW. Takahiro Iwata Yamagata University. Quark Confinement and the Hadron Spectrum X, Oct. 8-12, 2012, Munich, Germany. OUTLINE. Introduction: Partonic Structure of (Pol.) Nucleon The Major Experiments Parton Distribution Functions Helicity PDF TDM PDF

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NUCLEON STRUCTURE OVERVIEW

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  1. NUCLEONSTRUCTUREOVERVIEW Takahiro IwataYamagata University Quark Confinement and the Hadron Spectrum X,Oct. 8-12, 2012, Munich, Germany

  2. OUTLINE • Introduction: Partonic Structure of (Pol.) Nucleon • The Major Experiments • Parton Distribution Functions • Helicity PDF • TDM PDF • GPD:3-dimensional picture of the nucleon • Conclusions Quark Confinement and the Hadron Spectrum X,Oct. 8-12, 2012, Munich, Germany

  3. INTRODUCTION: Partonic structure of (pol.) nucleon Quark Confinement and the Hadron Spectrum X,Oct. 8-12, 2012, Munich, Germany

  4. Quark Model and the EMC Finding Constituent Quark Model the spin of the nucleon is given by the spin of the quarks Quark spin contribution DS=Du+Dd=100% where Du=u↑-u↓, Dd=d↑-d↓ EMC 1988 quark spin contribution is consistent with zero! DS=Du+Dd+Ds=0.12 +- 0.17  SPIN CRISIS Quark Confinement and the Hadron Spectrum X,Oct. 8-12, 2012, Munich, Germany

  5. Partonic Structure of the Nucleon A lot of efforts to solve the problem. How does each parton share the nucleon spin? • Polarized parton distribution functions • Helicity distributions • Dq=q↑(x)- q↓(x)：　flavor decomposition • DG=g↑(x)- g↓(x) :polarized gluon distribution • Transverse Momentum Dependent (TMD) PDF • Orbital Angular Momentum(OAM) of quarks • 3-dimensional picture of the nucleon • Generalized Parton Distribution (GPD) • Jq : total angular momentum carried by quarks Quark Confinement and the Hadron Spectrum X,Oct. 8-12, 2012, Munich, Germany

  6. DIS and SI-DIS The research conducted by DIS ( Inclusive DIS) momentum fraction of the struck quark in Bjorken limit : Fragmentation Function Inclusive DIS: only the scattered leptons are measured Semi-Inclusive DIS: at least one final state hadrons are measured as well as the scattered leptons Quark Confinement and the Hadron Spectrum X,Oct. 8-12, 2012, Munich, Germany

  7. The Major Experiments Quark Confinement and the Hadron Spectrum X,Oct. 8-12, 2012, Munich, Germany

  8. HERMES DIS & SI-DIS experiment Detector: Dp/p~2%, Dq<1 mrad hadron ID (p, K, p) Pol. e- & e+ in HERA at 27 GeV Recoil Proton Detector for DVCS measurements data taking: 1996-2007 shutdown : 2007 data analysis on going Quark Confinement and the Hadron Spectrum X,Oct. 8-12, 2012, Munich, Germany

  9. COMPASS data taking: 2002- running experiment COMPASS-II in future MuonWall Straws SDC MWPC W45 E/HCAL E/HCAL SM2 SM1 Polarised solid Target SciFi Silicon Micromegas GEMs MuonWall RICH • two stage spectrometer • Large Angle Spectrometer (SM1) • Small Angle Spectrometer (SM2) • tracking, calorimetry, PID • Pol. • beam • 160GeV, • pol. 80% DIS & SI-DIS experiment Quark Confinement and the Hadron Spectrum X,Oct. 8-12, 2012, Munich, Germany

  10. JLab Experiments 6 GeV polarized electron beam Pol=85%, 180mA to be upgraded up to 12 GeV by 2014 several types of polarized targets  various polarization experiments Hall C CLAS in Hall B Hall A Quark Confinement and the Hadron Spectrum X,Oct. 8-12, 2012, Munich, Germany

  11. Polarized p p Collider : RHIC at BNL RHIC pC Polarimeters Complementary approach aside from DIS Absolute Polarimeter (H jet) ANDY/ BRAHMS E-Lens and Spin Flipper Siberian Snakes Siberian Snakes PHENIX STAR Spin Rotators (longitudinal polarization) Spin Rotators (longitudinal polarization) Pol. H- Source LINAC EBIS BOOSTER Helical Partial Siberian Snake AGS 200 MeV Polarimeter AGS pC Polarimeter Strong AGS Snake Ös =62.4, 200, 500 GeV Polarization: Pmax=57% Quark Confinement and the Hadron Spectrum X,Oct. 8-12, 2012, Munich, Germany

  12. Parton Distribution Functions Quark Confinement and the Hadron Spectrum X,Oct. 8-12, 2012, Munich, Germany

  13. PDFs at LO neglecting kT Nucleon unpol. long. pol. trans. pol. number density unpol. Nucleon Parton helicity long. pol. Quark transversity trans. pol. Only three functions to describe the nucleon structure Quark Confinement and the Hadron Spectrum X,Oct. 8-12, 2012, Munich, Germany

  14. TMD PDFs taking account of kT, 8 TMD PDFs are necessary for a full description of uncleon structure at LO (Transverse Momentum Dependent PDFs) Nucleon unpol. long. pol. trans. pol. number density Sivers unpol. Nucleon T-odd Parton worm-gear-1 helicity long. pol. Quark transversity Boer-Mulders survive after integration over kT pretzelosity trans. pol. worm-gear-2 T-odd Quark Confinement and the Hadron Spectrum X,Oct. 8-12, 2012, Munich, Germany

  15. Helicity Distributions Quark Confinement and the Hadron Spectrum X,Oct. 8-12, 2012, Munich, Germany

  16. Pol. DIS & Spin Structure Function ・　photon nucleon asymmetry ・　spin structure function Spin Structure Function g1 available in wide kinematic range with complementary information: WEAK DECAY CONSTANTS (F,D) Proton Deuteron by COPASS Quark Confinement and the Hadron Spectrum X,Oct. 8-12, 2012, Munich, Germany

  17. Semi-Inclusive DIS Asymmetries : Fragmentation Function form quark(q) to hadron(h) with z for proton target • flavor decomposition Quark Confinement and the Hadron Spectrum X,Oct. 8-12, 2012, Munich, Germany

  18. Flavor Decomposition by COMPASS curves: DSSV fit at NLO PRL 101 (2008) 072001, PR D 80 (2009) 034030 COMPASS/ PL B 693 (2010) 227 from Inclusive-DIS and SI-DIS asymmetries for proton and deuteron targets LO analysis Quark Confinement and the Hadron Spectrum X,Oct. 8-12, 2012, Munich, Germany

  19. Helicity Distributions from Global Analysis NLOQCD Analysis with DIS and SI-DIS data only by LSS xDs=xDs-bar xDu-bar xDu xDd-bar x x Sea quark distributions small, but still with uncertainties xDd gluon distribution shows large uncertainty, even sign notdetermined positive gluon distribution can not be ruled out xDG x Du and Dd well determined negative gluon distribution (with node) Q2=4GeV2 Quark Confinement and the Hadron Spectrum X,Oct. 8-12, 2012, Munich, Germany

  20. Polarized Sea ; W-Production @ RHIC Single Spin Asymmetry for W-production Information on sea quark distributions statistics not enough to choose models luminosity upgrade in future program Quark Confinement and the Hadron Spectrum X,Oct. 8-12, 2012, Munich, Germany

  21. Gluon Polarization in DIS Experiments not inconsistent with global analysis Double Spin Asymmetry for Photon-Gluon fusion SMC HERMES, COMPASS consistent with 0 polarization in this range. Quark Confinement and the Hadron Spectrum X,Oct. 8-12, 2012, Munich, Germany

  22. Gluon Polarization Study in RHIC Inclusive Jet ALL@200 GeV p0 ALL@200 GeV Run5 Run6 Run9 de Florian et al., PRL 101, 072001 (2008) The 4th International Workshop of High Energy Physics in the LHC Era Valparaiso, Chile, January 4-10, 2012, K.Tanida global NLO analysis including DIS, SIDIS, and RHIC pp data More data expected in future inclusive jet ALL in 500 GeV collisions during 2012 and 2013 Future running at 200 GeV expected to significantly reduce uncertainties relative to 2009 data as well constraint for DG Quark Confinement and the Hadron Spectrum X,Oct. 8-12, 2012, Munich, Germany

  23. Transverse Spin Effects Quark Confinement and the Hadron Spectrum X,Oct. 8-12, 2012, Munich, Germany

  24. Modulation in SIDIS for Transversity & TMD PDFs fS= azim. angle of nucleon spin (initial quark spin) fS’= azim. angle of struck quark spin fS=p - fS’（due to helicity conservation) fh= azim. angle of leading hadron Transversity PDF SI-DIS for transv. pol. target expected to give modulation: Collins F.F. Collins Sivers PDF Sivers Collins angle: Azim. angle of a hadron wrt struck quark spin FC =fh - fS’ (=fh +fS-p) Sivers angle:Azim. angle of a hadron wrt nucleon spin FS=fh - fS s: nucleon spin (initial quark spin) s’: struck quark spin Scattering plane quark direction hadron （Breit frame） Quark Confinement and the Hadron Spectrum X,Oct. 8-12, 2012, Munich, Germany

  25. Collins Asymmetries non-zero asymmetris Deuteron data also available from COMPASS

  26. Transversity PDF Global Analysis Anselmino et al. Phys. Rev. D 75 (2007) 054032 • fit to AColld from COMPASS, ACollp from HERMES • and Collins F.F. from BELLE (e+e- scattering) • ・　RecentCOMPASS proton data ACollp not included in the fit Transversity PDF Helicity PDF u Opposite signs to each other, Shapes are similar to Helicity PDF But intensities are slightly smaller xDu d Soffer bound xDd Quark Confinement and the Hadron Spectrum X,Oct. 8-12, 2012, Munich, Germany

  27. Sivers Asymmetries positive pion gives positive asymmetry negative pion gives zero asymmetry Deuteron data also available from COMPASS

  28. Sivers PDF Global Analysis GPD-E “lensing function” Sivers PDF constraint by anomalous magnetic moments fit to ASiv.d from COMPASS, ASiv.p from HERMES ASiv.n from Jlab Sivers PDF (kT2 integrated) u d u-quark non-zero Sivers PDF  OAM of quarks d-quark Quark Confinement and the Hadron Spectrum X,Oct. 8-12, 2012, Munich, Germany

  29. A Future Program for Transverse Spin Effect • COMPASS-II: Pion induced Drell-Yan for transversely pol. target • p -+p↑ m++m - + Xat Pp =190 GeV/c Azimuthal angle modulations give access to TMD PDFs ( Sivers , Boer-Mulders, Pretzelosity ) Target transversely pol. p The Sivers PDF has naïve time reversal odd character so that a sign change between DY and SIDIS is expected (Universality) SI-DIS COMPASS-II (DY) will run in 2014 Crucial test for non-perturbative QCD Quark Confinement and the Hadron Spectrum X,Oct. 8-12, 2012, Munich, Germany

  30. GPD: 3-dimensional Picture of the Nucleon Quark Confinement and the Hadron Spectrum X,Oct. 8-12, 2012, Munich, Germany

  31. GPD & DVCS *  Q² x+ x- p GPDs t p Generalized Parton Distribution (GPD) a key concept for nucleon structure Deeply Virtual Compton Scattering (DVCS) described with GPD ep ep Relation to the parton densities Forward limit (x0,t 0) GPD Relation to nucleon elastic form factors Dirac form factor GPDs: (in twist-2 level) Vector Tensor Axial vector Pseudo scalar Pauli form factor negative x means anti-quark Quark Confinement and the Hadron Spectrum X,Oct. 8-12, 2012, Munich, Germany

  32. Ji’s Sum Rule & 3D-Picture b y x P x z boost GPDs give total angular momentum of quarks total angular momentum of quark with flavor q give access to OAM of quarks relation to the Impact Parameter Dependent PDFs un-pol. longitudinal-pol. GPD transverse-pol. quark distribution as a function of transverse position and longitudinal momentum  3-D picture Quark Confinement and the Hadron Spectrum X,Oct. 8-12, 2012, Munich, Germany

  33. GPD in HERMES Beam-Spin Asymmetry Pioneering work for DVCS to extract GPDs DVCS along with BH @HERMES, Jlab and Target-Spin-Asymmetry Beam-Charge-Asymmetry Known PRL 87 (2001) 182001 DVCS Bethe-Heitler Interference Need careful analysis to extract DVCS amplitude JHEP 06 (2008) 066 Quark Confinement and the Hadron Spectrum X,Oct. 8-12, 2012, Munich, Germany Compton form factors of GPDs

  34. GPD in JLab Beam-Spin asymmetries by CLAS Jlab experiments are playing an important role to study GPD Hall A: high accuracy, limited kinematics, Hall B: wide kinematic range, limited accuracy Ee=5.766 GeV arXiv:1201.0440v2 Quark Confinement and the Hadron Spectrum X,Oct. 8-12, 2012, Munich, Germany

  35. Further Studies on GPD • COMPASS-II • DVCS for proton with polarized m+ and m - at 160GeV/c • Dominant DVCS signals expected at high energies • plan to run in 2015,16 • Phase-2: DVCS measurement with pol. target • JLab-12GeV • precise measurements at higher energies • ・Hall A: E12-06-114 fixed x, several Q2 , several beam energies, • t-dependence, Im H, Re H • ・Hall B: E12-06-119 large kinematic coverage with CLAS • beam energy at 11GeV, high statistics, BSA, TSA • ・ Hall B: E12-11-003 CLAS with new recoil neutron detector, • BSA, flavour separation of GPD-H •  Constraints on the GPD will be given in near future Quark Confinement and the Hadron Spectrum X,Oct. 8-12, 2012, Munich, Germany

  36. Conclusions • Significant progress in the study of nucleon spin structure • Flavor decomposition of helicity distribution was carried out • Good determination for Du and Dd, but poor for sea distributions • Polarized gluon distribution has still uncertainty • Efforts for gluon polarization measurements have been taken • Transversity and Sivers PDF have been extracted • Non-zero Sivers PDF suggests presence of OAM of quarks • DVCS measurements for the extraction of GPDs are in progress • Exciting future programs at COMPASS-II, RHIC and JLab-12GeV Quark Confinement and the Hadron Spectrum X,Oct. 8-12, 2012, Munich, Germany

  37. BACKUP SLIDES Quark Confinement and the Hadron Spectrum X,Oct. 8-12, 2012, Munich, Germany

  38. Coverage of the DIS Experiments IWHSS 2012 Quark Confinement and the Hadron Spectrum X,Oct. 8-12, 2012, Munich, Germany

  39. Semi-Inclusive DIS Asymmetries (deuteron) Quark Confinement and the Hadron Spectrum X,Oct. 8-12, 2012, Munich, Germany

  40. GPD Global Analysis with JLab Data helicity dependent and independent cross sections (Hall A) beam spin asymmetries (Hall B) 0.09 < -t <0.2 GeV 2 0.2 < -t <0.4 GeV 2 0.4 < -t <0.6 GeV 2 0.6 < -t <1.0 GeV 2 VGG model prediction systematic uncertainties dominant VGG model Quark Confinement and the Hadron Spectrum X,Oct. 8-12, 2012, Munich, Germany

  41. GPD from JLab Hall A data: Phys.Rev.Lett. 97, 262002 beam-spin diff. fit: Eur.Phys.J. A 37, 312, (2008) Quark Confinement and the Hadron Spectrum X,Oct. 8-12, 2012, Munich, Germany

  42. DVCS & BH Energy Dependence DVCS BH Quark Confinement and the Hadron Spectrum X,Oct. 8-12, 2012, Munich, Germany

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