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Kwangbok Lee Korea University Heavy Ion physics and heavy quarkonia: focused on Upsilon and chi_c measurement 1 Kwangbok Lee - 22 Nov. 2010
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Heavy Ion physics and heavy quarkonia : focused on Upsilon and chi_c measurement. Kwangbok Lee Korea University. Outline. Heavy Ion physics - A + A collision -> J/psi, heavy quarkonia - p ( d ) + A collision (Cold nuclear matter) - PowerPoint PPT Presentation

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d+Au Physics at PHENIX forward

Kwangbok LeeKorea UniversityHeavy Ion physics and heavy quarkonia: focused on Upsilon and chi_c measurement1

Kwangbok Lee - 22 Nov. 20101Heavy Ion physics - A + A collision -> J/psi, heavy quarkonia - p(d) + A collision (Cold nuclear matter) -> Shadowing effect, nuclear absorption, gluon saturation, initial state energy loss measurement in d + Au collision (Preliminary)cc measurement in d + Au collision (Challenging, ongoing)Future prospect

Kwangbok Lee - 22 Nov. 20102

Outline

23Heavy Ion physics

Kwangbok Lee - 22 Nov. 2010The phase diagram of QCD matter

History of the Universe

presentFirst SupervovaeGalaxy & Star FormationAtom FormationHe FormationWI & QED Separate Quark Gluon PlasmaEW & QCD Separate(GUT)Big Bang

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4Heavy Ion Collision

Kwangbok Lee - 22 Nov. 2010

The space-time diagram of a heavy ion collisionTimeTime1. About to collide

2. Collide

3. QGP

4. Hadronize(Freeze out)

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Kwangbok Lee - 22 Nov. 2010

SPSRHICEnergy Density

Sequential J/ suppressionby colour screeningSeveral scenarios may contribute: Suppression by the color screening Cold nuclear matter (CNM) effect Regeneration effectSatz, hep-ph/05122175J/psi suppression

Charmonium system

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hep-ph/0609197v1 H. Satz Each quarkonium has different binding radius. stateJ/y(1S)cc(1P)(1S)(2S)(3S)mass [GeV]3.103.539.4610.0210.36radius [fm]0.250.360.140.280.39Td/Tc2.101.16> 4.01.601.17hep-ph/0512217

At RHIC, 3S melts and the 2S is likely to melt, the 1S is expected to survive. - S. Digal et.al., Phys. Lett. B 514 (2001) 57. C-Y Wong, Phys. Rev. C 72 (2005) 034906.

Quarkonia & Color deconfinement

Kwangbok Lee - 22 Nov. 2010ccbbSchematic of color screening

6Schematic illustration of Au + Au collisionSchematic illustration of d + Au collisionABBAABBA7Cold Nuclear Matter (CNM)

Kwangbok Lee - 22 Nov. 2010 Since, in p(d)A collisions, no hot and dense medium is expected to be created, the matter created is called cold nuclear matter (CNM). The CNM can provide the quantitative comparison to the measurement of A + A collision so can provide a better understanding of the effects beyond CNM from hot and dense nuclear matter. CNM is an interesting matter itself.

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RGPb

Q2 = 1.69 GeV2EPS08EPS09nDSEKS98HKN07 Shadowing model Nuclear absorption Initial state parton energy losslow xhigh xantishadowingGluon density in different xarXiv:0902.4154

Cold Nuclear Matter (CNM)

Kwangbok Lee - 22 Nov. 2010shadowingJ/y1S

1S J/yRapidityX28

9Ncoll : number of binary (pp) collisions in one HI collision. If the production of AA behaves like in pp, RdAu = Rcp = 1 If there is suppression, RdAu , Rcp < 1ppdAu(all centralities)dAu(0-20%)dAu(60-88%)Ncoll17.6 0.415.1 1.03.2 0.2

Nuclear modification factors

Kwangbok Lee - 22 Nov. 2010

9Run06Run7Run08Collision typeppAuAuppdAusNN (GeV/c2)200200200200Ldt10.7 pb-10.8 nb-15.2 pb-180 nb-110Upsilon analysis

Kwangbok Lee - 22 Nov. 2010 Run 8 (2008) d+Au data and Run 6 (2006) p+p data are used. -> provide Upsilon cross section, and Upsilon nuclear modification factor, RdAu. Physical backgrounds of Drell Yan, open charm and open beauty are simulated and excluded. (Recently, we got NLO Drell Yan calculation, so doing updates).

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SouthNorth + - ~ -1.7, x2 ~ 0.2Gold going direction ~ 1.7, x2 ~ 0.01deuteron going directionthought to be in shadowing region

dAuPHENIX Muon arm

Kwangbok Lee - 22 Nov. 2010

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Unlikesign event Scaled Mixed event Signal : Unlikesign Scaled Mixed event12Invariant mass distribution

Kwangbok Lee - 22 Nov. 2010 Estimated combinatorial background by event mixing There might be physical background in Upsilon mass region such as Drell-Yan, correlated open beauty and correlated open charm

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DY events were embedded to real data to reflect more realistic environment. Fit the reconstructed points with exponential function. Shape and absolute value are extracted to fit the real data.13Drell-Yan process - simulation

Kwangbok Lee - 22 Nov. 2010

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Pythia generation and generation by randomizing angle were considered. Reconstructed through PHENIX simulation application chain.14Correlated open beauty - simulation

Kwangbok Lee - 22 Nov. 2010

14 Did same procedure with correlated beauty estimation. Charm isnt estimated to affect Upsilon mass range much.15Correlated open charm - simulation

Kwangbok Lee - 22 Nov. 2010

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statesMass (GeV)B.R. of +-(%)Compositionat CDF s=1.8TeVCompositionat FNAL E605s = 39 GeV1S9.462.4873 %72 %2S10.021.9317 %19 %3S10.362.2910 %9 %

16Upsilon - simulation

Kwangbok Lee - 22 Nov. 2010

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Drell Yan, correlated bottom, correlated charm and Upsilon are considered to fit the data points. Apply the shape and the absolute value of each component from simulation to fit the data.17Fitting real data (p + p data set)

Kwangbok Lee - 22 Nov. 2010

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18Fitting real data (d + Au data set)

Kwangbok Lee - 22 Nov. 2010 Drell Yan, correlated bottom, correlated charm and Upsilon are considered to fit the data points. Apply the shape and the absolute value of each component from simulation to fit the data.

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BR*d/dy = 31.18.7(stat.)6.2(syst.)pb, y [1.2, 2.2]BR*d/dy = 28.29.4(stat.)4.8(syst.)pb, y [-2.2, -1.2]

19Upsilon cross section in p + p

Kwangbok Lee - 22 Nov. 2010 Shape matches CEM well (scaled down by factor of 2)

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Upsilon RdAu in d+Au/p+p20RdAu = 0.840.34(stat.)0.20(sys.), y [-2.2, -1.2]RdAu = 0.530.20(stat.)0.16(sys.), y [1.2, 2.2]

Kwangbok Lee - 22 Nov. 2010 Shows suppression at low x region

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RdAu = 0.78+-0.28(stat.)+-0.20(sys.) at mid rapidityRAuAu < 0.64 at 90% C.L.at mid rapidity

21Another Upsilon measurements

Kwangbok Lee - 22 Nov. 2010

2122chi_c Analysis

Kwangbok Lee - 22 Nov. 2010Run06Run7Run08Collision typeppAuAuppdAusNN (GeV/c2)200200200200Ldt10.7 pb-10.8 nb-15.2 pb-180 nb-1 Run8 d+Au collision and Run8 p+p collision are being analyzed. Small MPC acceptance -> big uncertainties -> make the analysis hard. Let me show the status.

2223chi_c Analysis

Kwangbok Lee - 22 Nov. 2010 Higher charmonium state(1P) than J/(1S). There are three states of chi_c. Radiative decay channel cc -> J/ + -> +-(e+e-) + . Rcc = (cc -> J/ + ) / (Inclusive J/). It would be a good tool to decouple the fraction of decay J/ and direct J/.

BR ratiocc0(3.41 GeV)cc1(3.51 GeV)cc2(3.56 GeV)J/(3.10 GeV)cc -> J/,1.16%34.4%19.5%J/ -> +-5.93%PDG 10

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Kwangbok Lee - 22 Nov. 201024

SouthNorthd + -

How can we detect chi_c?

Forward E.M. Calorimeter(MPC) 3.1 < |y| < 3.9

AuMPCMuon arm

24PHENIX acceptance25-3 -2 -1 0 1 2 3 rapidity0 f coverage 2pEMCAL +Central TrackerMPCMPCEMCAL +Central TrackerSouth Muon TrackerNorth Muon TrackerBackward & Forward Calorimetry

Kwangbok Lee - 22 Nov. 2010

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26MPC acceptance by Pythia

Kwangbok Lee - 22 Nov. 2010

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Chi_c decay photon energy in MPC

Inclusive photon energy in MPC 27MPC photon energy distribution

Kwangbok Lee - 22 Nov. 2010Low energy background !!

27Single cc photon vs J/ rapidity28Kinematic cuts (2D)

Kwangbok Lee - 22 Nov. 2010

Embedded cc photon vs J/ rapidity

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Peak : 0.429 GeVPeak : 0.424 GeVNorth armSouth Arm29chi_c1 embedding simulation

Kwangbok Lee - 22 Nov. 2010x-axis: +-(three particle correlated mass) +-(dimuon mass)Foreground eventScaled mixed eventSignal(Foreground Mixed)

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North armSouth ArmForeground eventScaled mixed eventSignal(Foreground Mixed)

Signal fitting with 2 Gaussians30Fitting to real data (p + p data set)

Kwangbok Lee - 22 Nov. 2010

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dAu North Peak is visible at small x region. South MPC has large background.31Fitting to real data (d + Au data set)

Kwangbok Lee - 22 Nov. 2010Foreground eventScaled mixed eventSignal(Foreground Mixed)

Rcc varies from 0.8 ~ 1.5 depending the cc distributions. Rcc values are still lager than expected. Trying to figure out where the enhancement comes from.

3132Another chi_c measurement

Kwangbok Lee - 22 Nov. 2010

World average is about 0.3. But it has large fluctuations and uncertainties.

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pmprompt

PHENIX upgrade

Kwangbok Lee - 22 Nov. 2010 Silicon VTX, Silicon FVTX(LANL), Muon trigger/RPC, etc. Silicon Forward Vertex (FVTX). -> Displaced vertex, Mass resolution. First Drell-Yan from RHIC. Separation of charm and beauty.

Quarkonia measurement is a good probe to understand matter created in the heavy ion collision.New Upsilon RdAu shows suppression in low x region and need to have theoretical comparison. cc feed down to J/y measurement is underway and will be important to decouple the cold nuclear matter effect and QGP state.34Summary

Kwangbok Lee - 22 Nov. 2010

34PHENIX detector upgrade is ongoing recently.. - Silicon VTX, Silicon FVTX(LANL), Muon trigger/RPC, etc. Forward Silicon Vertex Detector (FVTX), led by the LANL group, will measure displaced vertices of the produced particles and improve the mass resolutions.With the FVTX, we expect to separate the Drell-Yan process, open charm and open beauty.35Future

Kwangbok Lee - 22 Nov. 2010

35Back upNLO Drell Yan estimation

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Kwangbok Lee - 22 Nov. 201038

Kwangbok Lee - 22 Nov. 2010

Forward Di-Hadron Df Correlations in d+Au3838

PHENIX Muon Piston Calorimeter

Technology ALICE(PHOS)

PbWO4 avalanche photo diode readout

Acceptance:

3.1 < < 3.9, 0 < < 2 -3.7 < < -3.1, 0 < < 2

Both detectors were installed for 2008 d-Au run.

PbWO4 + APD + Preamp Assembly at UIUCMPC integrated in thepiston of the muonspectrometer magnet.3838

39Chi_c distribution and Rcc

Kwangbok Lee - 22 Nov. 2010

Rcc varies from 0.8 ~ 1.5 by the cc distributions. Rcc values are still lager than expected. Trying to figure out where the enhancement comes from.

cc rapidityDecay rapidity = 1.5 = flatGive different MPC acceptanceof 3.8 % ~ 5.7 %

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Uncertainty summarypp Southpp NorthdAu SouthdAu NorthUpsilon mass resolution0%0%4%2%Drell Yan slope14%18%8%16%Open Bottom variation7%7%9%5%Muid efficiency4%4%4%4%MuTRefficiency2%2%2%2%SystematicTotal(Quadratic sum)16%20%13%17%BBC(Global) 10%10%5.65%5.65%Statistical Uncertainty29%28%8%20%Table. Uncertainty summary

Kwangbok Lee - 22 Nov. 201040Invariant yield and cross sectionsLumi.Raw countAcc*Eff.GeometricalAcceptanceInvariantyieldcross section1.2