NUCLEON STRUCTURE OVERVIEW Takahiro Iwata Yamagata University Quark Confinement and the Hadron Spectrum X,　Oct. 8-12, 2012, Munich, Germany

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

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

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 Takahiro Iwata Quark Confinement and the Hadron Spectrum X,　Oct. 8-12, 2012, Munich, Germany

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 Takahiro Iwata Quark Confinement and the Hadron Spectrum X,　Oct. 8-12, 2012, Munich, Germany

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 Takahiro Iwata Quark Confinement and the Hadron Spectrum X,　Oct. 8-12, 2012, Munich, Germany

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

HERMES Detector: Dp/p~2%, Dq<1 mrad Pol. e- & e+ in HERA at 27 GeV 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 Takahiro Iwata Quark Confinement and the Hadron Spectrum X,　Oct. 8-12, 2012, Munich, Germany

COMPASS data taking: 2002- running experiment COMPASS-II in future MuonWall Straws SDC MWPC W45 E/HCAL E/HCAL SM2 Polarised solid Target SM1 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 Takahiro Iwata

JLab Experiments 6 GeV polarized to be upgraded 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 Takahiro Iwata Quark Confinement and the Hadron Spectrum X,　Oct. 8-12, 2012, Munich, Germany

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

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

PDFs at LO Quark Nucleon unpol. long. pol. trans. pol. unpol. 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 Takahiro Iwata Quark Confinement and the Hadron Spectrum X,　Oct. 8-12, 2012, Munich, Germany

TMD PDFs Quark Nucleon unpol. long. pol. trans. pol. unpol. long. pol. 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 Parton T-odd worm-gear-1 helicity long. pol. Quark transversity Boer-Mulders survive after integration over kT trans. pol. worm-gear-2 pretzelosity T-odd Takahiro Iwata Quark Confinement and the Hadron Spectrum X,　Oct. 8-12, 2012, Munich, Germany

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

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 Takahiro Iwata Quark Confinement and the Hadron Spectrum X,　Oct. 8-12, 2012, Munich, Germany

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

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 Takahiro Iwata Quark Confinement and the Hadron Spectrum X,　Oct. 8-12, 2012, Munich, Germany

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

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 Takahiro Iwata Quark Confinement and the Hadron Spectrum X,　Oct. 8-12, 2012, Munich, Germany

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. Takahiro Iwata Quark Confinement and the Hadron Spectrum X,　Oct. 8-12, 2012, Munich, Germany

global NLO analysis including DIS, SIDIS, and RHIC pp data Gluon Polarization Study in RHIC Run5 Run6 Run9 Inclusive Jet ALL@200 GeV p0 ALL@200 GeV 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 Takahiro Iwata Quark Confinement and the Hadron Spectrum X,　Oct. 8-12, 2012, Munich, Germany

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

Modulation in SIDIS for Transversity & TMD PDFs 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 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 quark direction hadron （Breit frame） Takahiro Iwata Quark Confinement and the Hadron Spectrum X,　Oct. 8-12, 2012, Munich, Germany

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

Anselmino et al. Phys. Rev. D 75 (2007) 054032 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) ・　Recent　COMPASS 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 Soffer bound d xDd Takahiro Iwata Quark Confinement and the Hadron Spectrum X,　Oct. 8-12, 2012, Munich, Germany

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

constraint by anomalous magnetic moments 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 d-quark u-quark Sivers PDF (kT2 integrated) u d non-zero Sivers PDF  OAM of quarks Takahiro Iwata Quark Confinement and the Hadron Spectrum X,　Oct. 8-12, 2012, Munich, Germany

A Future Program for Transverse Spin Effect COMPASS-II: Pion induced Drell-Yan for transversely pol. target　 p -+p↑ m++m - + X at Pp =190 GeV/c Target transversely pol. p Azimuthal angle modulations give access to TMD PDFs ( Sivers , Boer-Mulders, Pretzelosity ) 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 Takahiro Iwata Quark Confinement and the Hadron Spectrum X,　Oct. 8-12, 2012, Munich, Germany

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

GPD & DVCS 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 p GPDs * Q² x+ x-  t Forward limit (x0,t 0) GPD Relation to nucleon elastic form factors GPDs: (in twist-2 level) Vector Tensor Axial vector Pseudo scalar Dirac form factor Pauli form factor negative x means anti-quark Takahiro Iwata Quark Confinement and the Hadron Spectrum X,　Oct. 8-12, 2012, Munich, Germany

Ji’s Sum Rule & 3D-Picture 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 x P x y b z boost un-pol. longitudinal-pol. GPD transverse-pol. quark distribution as a function of transverse position and longitudinal momentum  3-D picture Takahiro Iwata Quark Confinement and the Hadron Spectrum X,　Oct. 8-12, 2012, Munich, Germany

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

Beam-Spin asymmetries by CLAS 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 Takahiro Iwata Quark Confinement and the Hadron Spectrum X,　Oct. 8-12, 2012, Munich, Germany

Further Studies on GPD COMPASS-II JLab-12GeV 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 Takahiro Iwata Quark Confinement and the Hadron Spectrum X,　Oct. 8-12, 2012, Munich, Germany

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 Takahiro Iwata Quark Confinement and the Hadron Spectrum X,　Oct. 8-12, 2012, Munich, Germany

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

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

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

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 Takahiro Iwata Quark Confinement and the Hadron Spectrum X,　Oct. 8-12, 2012, Munich, Germany

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

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