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H eavy quark production in p+p and d+Au collisions at √s NN = 200 GeV

For the collaboration. H eavy quark production in p+p and d+Au collisions at √s NN = 200 GeV. Youngil Kwon Univ. of Tennessee. Quark Matter 2005 Budapest , Hungary, 4-9 August , 2005. Outline. Physics Motivations ( pQCD & parton model )

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H eavy quark production in p+p and d+Au collisions at √s NN = 200 GeV

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  1. For the collaboration Heavy quark production in p+p and d+Au collisions at√sNN= 200 GeV Youngil Kwon Univ. of Tennessee Quark Matter 2005 Budapest, Hungary,4-9August, 2005

  2. Outline Physics Motivations (pQCD & parton model) PHENIX (with some emphasis on  aspect) Open heavy-flavor (charm) measurements • Method (semi-leptonic decays and single leptons) • Selected results fornon-photonic e (y ~ 0)& prompt(y ~ 1.65)production from • p+p collisions at √s = 200 GeV • d+Au collisions at √sNN = 200 GeV as a function of centrality Near term prospect (leptons over wide rapidity) Summary & Outlook Y. Kwon for PHENIX @ QM2005, Budapest

  3. Physics Motivations Fundamental quest of our field: Exploration of QCD in various limits. • Scenarios in discussion : • For the p - p collisions • Is mass of charm quark heavy enough? Can pQCD be applied to charmproduction? • J.C.Collins, D.E.Soper, G.Sterman, Nucl. Phys. B263, 37(1986) • For the d - Au collisions • Does “binary scaling” work? • If charm producing process is point-like and there’sno modification of the initial parton distributionor the final fragmentation,there will be scaling • with the number of binary nucleon collisions Ncoll. • CGC ( Color Glass Condensate ) • There will be modification of the initial parton distribution, and the scaling • will be modified as a function of rapidity. • D. Kharzeev et al, Phys. Lett. B599 (2004) 23-31 Y. Kwon for PHENIX @ QM2005, Budapest

  4. ds [A+BH+X] = Sijfi/A fj/Bds [ijcc+X]DcH + ... ds [ijcc+X] : calculable parton cross section Hard processes and factorization Factorization J.C.Collins,D.E.Soper and G.Sterman, Nucl. Phys. B263, 37(1986) fi/A, fj/B : distribution function for point-like parton i,j Point-like, Process independent Dc/H : fragmentation function for c + ... : higher twist (power suppressed by LQCD/mc, or LQCD/pt if pt ≫mc ) : e.g. "recombination" E.Braaten, Y.Jia, T. Mehen, PRL, 89 122002 (2002) Power-suppressed Y. Kwon for PHENIX @ QM2005, Budapest

  5. Fragmentation measurement Semileptonic decay PHENIX, How to measure heavy flavor? Semi-leptonic decays contribute to single lepton spectra! Spectator model? Peterson function? Larger uncertainty in fragmentation function! b fragmentation function (HERWIG) e+e-, √s = 91.2 GeV ppbar, √s = 1.8TeV S. Frixione et al, J. Phys. G 27(2001)1111 Y. Kwon for PHENIX @ QM2005, Budapest

  6. Electrons: central arms measurement range:|h|  0.35 p  0.2 GeV/c Muons: forward arms measurement range: 1.2 < |h| < 2.4 p  2 GeV/c two central electron/photon/hadron spectrometers two forward muon spectrometers PHENIX Optimized for lepton measurements Y. Kwon for PHENIX @ QM2005, Budapest

  7. Mostly from heavy quark Direct measurement : converter method Estimation based on other (PHENIX) measurement : Cocktail method Inclusivee±, p+p at√s = 200 GeV Inclusive electrons = photonic + non-photonic electron Dominant background : 0 Dalitz decay,  conversion Y. Kwon for PHENIX @ QM2005, Budapest

  8. Collision 2 1 3 4 5 1 : Hadrons, interacting and absorbed (98%), 2 : Charged /K's,“decaying into ”before absorber (≤1%), 3: Hadrons, penetrating and interacting(“stopped”) 4 : Hadrons, “punch-through”, 5 : Prompt , ”desired signal” -measurement, Sources Tracker Absorber Identifier zcoll zcoll zcoll Collision vertex range Symbols Hadron Detector Absorber Muon Y. Kwon for PHENIX @ QM2005, Budapest

  9. decay muons + punch-through PRELIMINARY -measurement, Signal extraction and level Generator 1. Light hadron measurement by PHENIX central arm (y = 0) 2. Gaussian extrapolation in rapidity to muon arm acceptance ( = 2.5) 3. Simplified spectrometer geometry. • Sources of  candidates • Decay  is important at all pT. • Punch-through is small, but • important due to large uncertainty. • Prompt signal comparable to decay • when pT ~ 2(GeV/c). Y. Kwon for PHENIX @ QM2005, Budapest

  10. PRELIMINARY PRELIMINARY Decay spectra p + p @√s = 200 GeV,  = 1.65 10 data points for +and for- correspond to the slopes for 10 pT bin ( 1 < pT < 1.2, 1.2 < pT < 1.4, … , 2.8 < pT < 3.0 GeV/c ). Each slope represents amount of decaying light hadrons, and good match occurs between the generator prediction and the measurement up to absolute normalization (5%). Hence we can determine decay component precisely. Y. Kwon for PHENIX @ QM2005, Budapest

  11. PRELIMINARY PRELIMINARY Final Non-photonice& Preliminary PromptInvariant Cross section p+p at√s = 200 GeV Muon spectra and electron spectra are similar over the observed pT range… For details of prompt muons analysis, please go to D. Hornback’s poster. Y. Kwon for PHENIX @ QM2005, Budapest

  12. PRELIMINARY Comparison to Theory, Cross section FONLL: Fixed Order next-to-leading orderterms and Next-to-Leading-Log large pTresummation. PYTHIA 6.205 parameters, tuned to describe existing s < 63 GeV p+N world data ( PDF – CTEQ5L, mC = 1.25 GeV, mB = 4.1 GeV, <kT> = 1.5 GeV, K = 3.5 ) We see excess over NLO calculation. The excess gets even stronger at forward, possibly due to the rapidity dependence of cross section. • Total cross section for PYTHIA 6.205 • CC = 0.658 mb, BB = 3.77 b Y. Kwon for PHENIX @ QM2005, Budapest

  13. d+Au,centrality definition & Glauber model count count NBBC Ncoll BBC -4 <  < -3 Y. Kwon for PHENIX @ QM2005, Budapest

  14. PHENIX PRELIMINARY PHENIX PRELIMINARY PHENIX PRELIMINARY 1/TABEdN/dp3 [mb GeV-2] 1/TABEdN/dp3 [mb GeV-2] 1/TAB 1/TAB 1/TABEdN/dp3 [mb GeV-2] PHENIX PRELIMINARY PHENIX PRELIMINARY 1/TABEdN/dp3 [mb GeV-2] 1/TABEdN/dp3 [mb GeV-2] 1/TAB 1/TAB Non-photonice±, d+Au at√sNN = 200 GeV Y. Kwon for PHENIX @ QM2005, Budapest

  15. PRELIMINARY Decay ’s ( from light hadrons ) Prompt ’s ( from heavy quarks ) Direction PRELIMINARY Au-going d-going Direction Au-going d-going pT(GeV/c) From M. K. Lee’s poster From X. R. Wang’s poster pT(GeV/c) ±& NMF, d+Au at √sNN= 200 GeV South : Au-going direction, North : d-going direction Y. Kwon for PHENIX @ QM2005, Budapest

  16. Summary & Outlook 1. PHENIX measured production of non-photonic e at mid-rapidity and prompt at forward/backward rapidities in p+p at √s = 200 GeV and d+Au at √sNN = 200 GeV. 2. We demonstrated single analysis is possible and presented the 1st results of the prompt  analysis. 3. Non-photonic e pTspectra at y = 0 and prompt pTspectra at y = 1.65 are similar. 4. Non-photonic e pT spectra at y = 0 showsexcessover the prediction by FONLL or PYTHIA 6.205 tuned to world data.Theprompt  pT spectra at y = 1.65 showseven stronger excess. 5. We observe “binary scaling” in non-photonic e production at midrapidity for d+Au collisions at √sNN = 200 GeV, which is consistent with the point-like interaction for charm production. 6. For the decay and the prompt  , there seem to be differences in production between the deuteron-going and the Au-going directions. Further Efforts will reduce measurement uncertainty. 7. PHENIX started to explore lepton production over wide rapidity range. Many new results will follow in the near future. Y. Kwon for PHENIX @ QM2005, Budapest

  17. Prospect Prospect Cu+Cu at √sNN = 200 GeV From D. J. Kim’s poster Y. Kwon for PHENIX @ QM2005, Budapest

  18. Brazil University of São Paulo, São Paulo China Academia Sinica, Taipei, Taiwan China Institute of Atomic Energy, Beijing Peking University, Beijing France LPC, University de Clermont-Ferrand, Clermont-Ferrand Dapnia, CEA Saclay, Gif-sur-Yvette IPN-Orsay, Universite Paris Sud, CNRS-IN2P3, Orsay LLR, Ecòle Polytechnique, CNRS-IN2P3, Palaiseau SUBATECH, Ecòle des Mines at Nantes, Nantes Germany University of Münster, Münster Hungary Central Research Institute for Physics (KFKI), Budapest Debrecen University, Debrecen Eötvös Loránd University (ELTE), Budapest India Banaras Hindu University, Banaras Bhabha Atomic Research Centre, Bombay Israel Weizmann Institute, Rehovot Japan Center for Nuclear Study, University of Tokyo, Tokyo Hiroshima University, Higashi-Hiroshima KEK, Institute for High Energy Physics, Tsukuba Kyoto University, Kyoto Nagasaki Institute of Applied Science, Nagasaki RIKEN, Institute for Physical and Chemical Research, Wako RIKEN-BNL Research Center, Upton, NY Rikkyo University, Tokyo, Japan Tokyo Institute of Technology, Tokyo University of Tsukuba, Tsukuba Waseda University, Tokyo S. Korea Cyclotron Application Laboratory, KAERI, Seoul Kangnung National University, Kangnung Korea University, Seoul Myong Ji University, Yongin City System Electronics Laboratory, Seoul Nat. University, Seoul Yonsei University, Seoul Russia Institute of High Energy Physics, Protovino Joint Institute for Nuclear Research, Dubna Kurchatov Institute, Moscow PNPI, St. Petersburg Nuclear Physics Institute, St. Petersburg St. Petersburg State Technical University, St. Petersburg Sweden Lund University, Lund 12 Countries; 58 Institutions; 480 Participants* USA Abilene Christian University, Abilene, TX Brookhaven National Laboratory, Upton, NY University of California - Riverside, Riverside, CA University of Colorado, Boulder, CO Columbia University, Nevis Laboratories, Irvington, NY Florida State University, Tallahassee, FL Florida Technical University, Melbourne, FL Georgia State University, Atlanta, GA University of Illinois Urbana Champaign, Urbana-Champaign, IL Iowa State University and Ames Laboratory, Ames, IA Los Alamos National Laboratory, Los Alamos, NM Lawrence Livermore National Laboratory, Livermore, CA University of New Mexico, Albuquerque, NM New Mexico State University, Las Cruces, NM Dept. of Chemistry, Stony Brook Univ., Stony Brook, NY Dept. Phys. and Astronomy, Stony Brook Univ., Stony Brook, NY Oak Ridge National Laboratory, Oak Ridge, TN University of Tennessee, Knoxville, TN Vanderbilt University, Nashville, TN *as of January 2004 Y. Kwon for PHENIX @ QM2005, Budapest

  19. RHIC • RHIC (Relativistic Heavy Ion Collider) • Dedicated to heavy ion physics & spin studies • 4 experiments • 100+100 GeV/A for various combinations of nuclei • p+p up to 500 GeV • Variable incident energy Y. Kwon for PHENIX @ QM2005, Budapest

  20. BBC PHENIX, Detectors for centrality Y. Kwon for PHENIX @ QM2005, Budapest

  21. Parton distribution for Au and d : fi/Au 79 fi/p + 118 fi/n 197 fi/N fi/d fi/p + fi/n 2 fi/N d+Au This scaling does not work for high pt particles in central Au+Au collisions! PHENIX, PRL, 91, 072303 (2003) Au+Au Application to nuclei For the interaction between point-like particles, Cross section number of colliding nucleon pairs, Ex) 197 * 2 for the d+Au collisions! Y. Kwon for PHENIX @ QM2005, Budapest

  22. Inclusive e/photonic e Mininum Bias Au+Au in sNN=200GeV Ne 1.7% 1.1% 0.8% With converter Conversion in converter W/O converter Conversion from detector Dalitz : 0.8% X0 equivalent Non-photonic 0 0 e-measurement, Signal Extraction (I) • Non-photonic signal relative to photonic electrons depends on pT & collision system . Y. Kwon for PHENIX @ QM2005, Budapest

  23. Photon conversions : • Dalitz decays of p0,h,h’,w,f (p0eeg, heeg, etc) • Kaon decays • Conversion of direct photons • Di-electron decays of r,w,f • Thermal di-leptons Most background isPHOTONIC • Charm decays • Beauty decays Non-PHOTONIC Signal p0  g g e+e- Background e-measurement, Sources Y. Kwon for PHENIX @ QM2005, Budapest

  24. “Non-photonic” Electron Invariant Cross section from Converter Subtraction Good agreement between two independent methods Y. Kwon for PHENIX @ QM2005, Budapest

  25. gconversion p0 gee h gee, 3p0 w ee, p0ee f ee, hee r ee h’  gee PHENIX: PRL 88(2002)192303 e-measurement, Signal Extraction (II) • excess above cocktail • increasing with pT • expected from charm decays • attribute excess to semileptonic decays of open charm Y. Kwon for PHENIX @ QM2005, Budapest

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