Latest results of nucleon spin structure measurements from PHENIX

1. Latest results of nucleon spin structure measurements from PHENIX RIKEN/RBRC Itaru Nakagawa

2. Brahms pp2pp PHENIX STAR The Relativistic Heavy Ion Collider accelerator complex at Brookhaven National Laboratory

3. RHIC p+p accelerator complex RHIC pC “CNI” polarimeters absolute pH polarimeter BRAHMS & PP2PP PHOBOS v vv RHIC Siberian Snakes PHENIX STAR Siberian Snakes Spin Rotators 5% Snake LINAC BOOSTER AGS pC “CNI” polarimeter Pol. Proton Source AGS Coulomb-Nuclear Interference 200 MeV polarimeter Rf Dipoles 20% Snake

4. PHENIX Experiment Pioneering High Energy Nuclear Interaction EXperiment

5. Universidade de São Paulo, Instituto de Física, Caixa Postal 66318, São Paulo CEP05315-970, Brazil Institute of Physics, Academia Sinica, Taipei 11529, Taiwan China Institute of Atomic Energy (CIAE), Beijing, People's Republic of China Peking University, Beijing, People's Republic of China Charles University, Ovocnytrh 5, Praha 1, 116 36, Prague, Czech Republic Czech Technical University, Zikova 4, 166 36 Prague 6, Czech Republic Institute of Physics, Academy of Sciences of the Czech Republic, Na Slovance 2, 182 21 Prague 8, Czech Republic Helsinki Institute of Physics and University of Jyväskylä, P.O.Box 35, FI-40014 Jyväskylä, Finland Dapnia, CEA Saclay, F-91191, Gif-sur-Yvette, France LaboratoireLeprince-Ringuet, EcolePolytechnique, CNRS-IN2P3, Route de Saclay, F-91128, Palaiseau, France Laboratoire de Physique Corpusculaire (LPC), UniversitéBlaise Pascal, CNRS-IN2P3, Clermont-Fd, 63177 AubiereCedex, France IPN-Orsay, Universite Paris Sud, CNRS-IN2P3, BP1, F-91406, Orsay, France Debrecen University, H-4010 Debrecen, Egyetemtér 1, Hungary ELTE, EötvösLoránd University, H - 1117 Budapest, Pázmány P. s. 1/A, Hungary KFKI Research Institute for Particle and Nuclear Physics of the Hungarian Academy of Sciences (MTA KFKI RMKI), H-1525 Budapest 114, POBox 49, Budapest, Hungary Department of Physics, Banaras Hindu University, Varanasi 221005, India Bhabha Atomic Research Centre, Bombay 400 085, India Weizmann Institute, Rehovot 76100, Israel Center for Nuclear Study, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan Hiroshima University, Kagamiyama, Higashi-Hiroshima 739-8526, Japan KEK, High Energy Accelerator Research Organization, Tsukuba, Ibaraki 305-0801, Japan Kyoto University, Kyoto 606-8502, Japan Nagasaki Institute of Applied Science, Nagasaki-shi, Nagasaki 851-0193, Japan RIKEN, The Institute of Physical and Chemical Research, Wako, Saitama 351-0198, Japan Physics Department, Rikkyo University, 3-34-1 Nishi-Ikebukuro, Toshima, Tokyo 171-8501, Japan Department of Physics, Tokyo Institute of Technology, Oh-okayama, Meguro, Tokyo 152-8551, Japan Institute of Physics, University of Tsukuba, Tsukuba, Ibaraki 305, Japan Chonbuk National University, Jeonju, Korea EwhaWomans University, Seoul 120-750, Korea Hanyang University, Seoul 133-792, Korea KAERI, Cyclotron Application Laboratory, Seoul, South Korea Korea University, Seoul, 136-701, Korea Myongji University, Yongin, Kyonggido 449-728, Korea Department of Physocs and Astronomy, Seoul National University, Seoul, South Korea Yonsei University, IPAP, Seoul 120-749, Korea IHEP Protvino, State Research Center of Russian Federation, Institute for High Energy Physics, Protvino, 142281, Russia INR_RAS, Institute for Nuclear Research of the Russian Academy of Sciences, prospekt 60-letiya Oktyabrya 7a, Moscow 117312, Russia Joint Institute for Nuclear Research, 141980 Dubna, Moscow Region, Russia Russian Research Center "Kurchatov Institute", Moscow, Russia PNPI, Petersburg Nuclear Physics Institute, Gatchina, Leningrad region, 188300, Russia Saint Petersburg State Polytechnic University, St. Petersburg, Russia Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Vorob'evy Gory, Moscow 119992, Russia Department of Physics, Lund University, Box 118, SE-221 00 Lund, Sweden 13 Countries; 70 Institutions Feb 2011 Abilene Christian University, Abilene, TX 79699, U.S. Baruch College, CUNY, New York City, NY 10010-5518, U.S. Collider-Accelerator Department, Brookhaven National Laboratory, Upton, NY 11973-5000, U.S. Physics Department, Brookhaven National Laboratory, Upton, NY 11973-5000, U.S. University of California - Riverside, Riverside, CA 92521, U.S. University of Colorado, Boulder, CO 80309, U.S. Columbia University, New York, NY 10027 and Nevis Laboratories, Irvington, NY 10533, U.S. Florida Institute of Technology, Melbourne, FL 32901, U.S. Florida State University, Tallahassee, FL 32306, U.S. Georgia State University, Atlanta, GA 30303, U.S. University of Illinois at Urbana-Champaign, Urbana, IL 61801, U.S. Iowa State University, Ames, IA 50011, U.S. Lawrence Livermore National Laboratory, Livermore, CA 94550, U.S. Los Alamos National Laboratory, Los Alamos, NM 87545, U.S. University of Maryland, College Park, MD 20742, U.S. Department of Physics, University of Massachusetts, Amherst, MA 01003-9337, U.S. Morgan State University, Baltimore, MD 21251, U.S. Muhlenberg College, Allentown, PA 18104-5586, U.S. University of New Mexico, Albuquerque, NM 87131, U.S. New Mexico State University, Las Cruces, NM 88003, U.S. Oak Ridge National Laboratory, Oak Ridge, TN 37831, U.S. Department of Physics and Astronomy, Ohio University, Athens, OH 45701, U.S. RIKEN BNL Research Center, Brookhaven National Laboratory, Upton, NY 11973-5000, U.S. Chemistry Department, Stony Brook University,SUNY, Stony Brook, NY 11794-3400, U.S. Department of Physics and Astronomy, Stony Brook University, SUNY, Stony Brook, NY 11794, U.S. University of Tennessee, Knoxville, TN 37996, U.S. Vanderbilt University, Nashville, TN 37235, U.S.

6. Global detectors beam-beam counter (BBC), zero-degree calorimeter (ZDC) Minimum-bias trigger Luminosity measurement Local polarimeter Philosophy high resolution at the cost of acceptance high rate capable DAQ excellent trigger capability for rare events Central Arms |h| < 0.35, Df = p/2×2 Momentum and energy measurement, particle-ID Detecting electron, photon, hadron Small amount of material to reduce conversion background Muon Arms 1.2 < |h| < 2.4 Momentum measurement and muon-ID Hadron absorber (muon piston) PHENIX detector

7. DG DouBleHelicity ALL Results

8. PDFs from Asymmetries • Example: • Choose channel with high statistics: p + p → π0 + X • Complicated mixture of amplitudes, changes as a function of kinematics. • How does one extract ΔG from the experimentally determined: • Requires calculational techniques based on factorization.

9. Factorization Δ Δfa,b=polarized quark and gluon distribution functions Dhf=fragmentation function for Δ Δ Partonic cross section from pQCD

10. Polarized gluon distribution (I) Sensitive to sign of g • p0 , p+/- • Central Rapidity • p0 Abundant Statistics • h Different fragmentation • Phys. Rev. D83,032001 (2011)

11. Polarized gluon distribution (II) High purity of glue-glue subprocess • Single e • Central + Forward Rapidity, Low Energy • Phys. Rev. D87, 012011 (2013) • 0 at s = 62.4 GeV High x • Forward Cluster Small x ~ 10-3 • Phys. Rev. D79, 012003 (2009) • sensitive to small-x  10-3

12. Extraction of Gluon Polarization HERMES COMPASS Jlab… PHENIX STAR (2005,2006) RHIC data constrain on gluon polarization! • Quark • Gluon • Strangeness • Anti-quark

13. QCD global analysis Interpretation DSSV++ (with latest results) First Positive Polarization DG Result :

14. Sea Quark PolarizationPreliminary ALWFrom Run12

15.  W-Boson Production @ √s = 500 GeV Parity Violation Asymmetry Clean flavor separation w/o fragmentation uncertainty

17. Single e,m PT Spectra W->e+ (Mid Rapidity) W->m+ (Forward Rapidity) W+BG S/B ~ 1/3 BG only • Background estimation in data driven manner • Resolution Improvement for better S/Nin progress Background PT [GeV/c] Signal

18. W-boson Asymmetry (Run12) • Boxes are systematic uncertainties from background • Run 2012 Beam Polarization uncertainty P/P = 3.4% (not shown) Poor knowledge of Sea quark Polarization Wide rapidity coverage

19. W measurement Run13 Projections Delivered Luminosity RHIC white paper Existing data Existing data + Run13 Data

20. Transverse Single Spin Asymmetry AN

21. Transverse structure of the nucleon • Single transverse-spin asymmetry • Expected to be small in hard scattering at high energies • FNAL-E704 • Unexpected large asymmetry found in the forward-rapidity region • Development of many models based on perturbative QCD p p

22. SP • kT,p • p • SP • p • p • p • Sq • kT,π Transverse-spin physics • Inclusive 0 • For establishment of TMDand higher-twistapproach • Single transverse-spin asymmetry(SSA) of inclusive hadrons • Siverseffect • Sivers distribution function (initial state) • transverse-momentum dependence of partons inside the transversely-polarized nucleon • Collinseffect • Transversity distribution (initial state) • correlation between transversely-polarized nucleon and transversely-polarized partons inside • Collinsfragmentation function (final state) • Higher-twisteffect • quark-gluon& multi-gluoncorrelation • Siverseffect • Collinseffect

23. Transverse-spin physics arXiv:1312.1995 To be published from PRD • Forward EM cluster at s = 200 GeV no decrese at high pT expected from higher-twist effect • Midrapidity0 and  constrains gluon Sivers effect

24. BBC hits neutron neutron Very Forward Neutron Single pion exchange? • large negative asymmetry • used for local polarimetry! Phys. Rev. D88, 032006 (2013)

25. 3-dimensional nucleon structure • Nucleon structure beyond the simple parton picture • Many-body correlation of partons • To describe the orbital motion inside the nucleon • Parton distribution in transverse direction • Extended/generalized picture of the parton distribution • Transverse-momentum dependence (TMD) • Space distribution (tomography) • Phenomenological model • with GPD data • Lattice QCD calculation

26. Phys Rev. D 83 094001 (2011) • arXiv 1208.1962v1 (2012) • Twist-3 p+p • prediction • AN • 49pb-1, P=0.6 • SIDIS (TMD) p+p prediction • xF • Charged clusters with >=3 tracks, single-trackp0’s MPC-EX upgrade • MPC-EX • MPC (Muon Piston Calorimeter) • Electromagnetic calorimeter • MPC-EX • Preshower detector • Commissioning in 2014 • Experiment in 2015-2016 • 3.1 < || < 3.8 • Installed in the muon piston • Direct photon asymmetry • To distinguish the Sivers effect and the higher-twist effect • Collins asymmetry in jets • 0correlation with jet-like clusters • MPC

27. sPHENIX upgrade • sPHENIX • Barrel upgrade • Forward upgrade • Partial installation and commissioning in 2018-2019 • Completion and experiment in 2021-2022 • Barrel upgrade baseline • Compact jet detector • Using upgraded RHICaccelerator • For precision measurement of jet, dijet, photon-jet correlationto understand the nature of QGP • Barrel upgrade extension • Additional tracking layers • Preshower detector • For heavy-flavor and internal jet structure measurements

28. sPHENIX forward upgrade • Open geometry • Wide kinematic coverage of photon, jet, leptons and identified hadrons • Compatible design for eRHICdetector (ePHENIX) • Constraint from IR design of eRHIC(|z| < 4.5m) • Hermeticity for exclusive measurements η~1 R (cm) R (cm) MuID η~-1 HCal HCal EMCal Aerogel EMCal& Preshower RICH η~4 Central silicon tracking GEM Station2 z (cm) Silicon Station1 GEM Station3 GEM Station4

29. sPHENIX forward upgrade • Sivers effect in Drell-Yanprocess • Valence quark region at x0.2with 1 <  < 4 coverage • Jet asymmetry • Siverseffect or higher-twisteffect • Asymmetry inside of jets • Collinseffect jet ® h+X twist 3 Fit of SIDIS s= 200 GeV y=3.3 jets SIDIS old

30. Summary • Origin of the nucleon spin 1/2 • Gluon-spin contribution AL • First non-zero positive gluon polarization by pQCD fit on Run9 data • Sea-quark contribution • Wide rapidity coverage. Sensitive to sea quark polarization at forward • Understanding of transverse-spin phenomena • Sivers effect / Collins effect / higher-twist effect • 3-dimensional nucleon structure • Many-body correlation of partons • AN measurements • The forward sPHENIX upgrades toward understanding of the 3-dimensional nucleon structure • Polarized Drell-Yan measurement / jet asymmetry and asymmetry inside of jets • Evolution to ePHENIX toward electron-proton collisions at eRHIC

31. backup

32. Run11 Central Arm W->e Run9 PRL106,062001 (2011) • Signal electron : • High momentum electron • Isolated Backgrounds could be mitigated by relative isolation cut

33. Single Electron PT Spectra Background Dominant Signal + Background • Power Law Counting Background Shape Fixed in 10<PT<20 GeV/c • Jacobian Peak (PYTHIA+GEANT) + Power Low Background Fitting • Resulting Background contamination 14 ~ 17%. Run11 Background Signal

34. Forward W-> m Analysis

35. Single Muon PT Spectra • Efficiency corrections • W/Z cross section employed RHICBOS NLO • S/B estimation from fixed W/Z cross section (RHICBOS NLO) S/B ~ 1/3 • Background estimation in data driven manner • Resolution Improvement for better S/N

36. The First Forward ALWResults First Forward W Asymmetry Results! More to come!

37. References [1]

38. Global Fit including Run9 0 ALL By S.Taneja et al (DIS2011) ala DSSV with slightly different uncertainty evaluation approach DSSV DSSV + PHENIX Run9 0 ALL No node … Uncertainties decreased A node at x~0.1 ?

39. Charged pion Cross Section Charge separated fragmentation functions are not well constrained in DSS FFs In good agreement with STAR

41. HBD Analysis for Heavy Flavor Decay e-

42. HBD Signal Occupancy

43. DG Extraction from ALLHFe • ALLopen charm ~|∆g/g(x, µ)|2 • |∆g(x, µ)| = C g(x, µ) is assumed • Results: • |∆g/g(⟨logx⟩,µ)|2 <3.3 ×10 −2 (1σ) and 10.9 ×10 −2 (3σ) • Open charm production dominates in pTrange of 0.50 < pT < 1.25 GeV/c (J/ψ <2%, b quark<5%) • pQCD prediction for ALLopen charm obtained from CTEQ6M PDFs + PYTHYA + LO hard scattering cross section

44. Central W Analysis

45. Central Arm AL

46.   ,0 The PHENIX Detector • Philosophy • high resolution & high-rate at the cost of acceptance • trigger for rare events • Central Arms • |h| < 0.35, Df ~ p • Momentum, Energy, PID • Muon Arms • 1.2 < |h| < 2.4 • Momentum (MuTr) • MuonPiston Calorimeter • 3.1 < |h| < 3.9 h+ m MPC

47. J/Ψ Drell Yan ϒ-states beauty charm Further Sea Quark Measurement w/ DY VTX FVTX (S) FVTX (N) VTX S/B contributionsw/o vertex detector High-mass DY Low-mass DY Extract DY events from heavy flavors using FVTX Invariant mass (GeV)