Masashi Kaneta

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Strangeness (and heavy flavor) at RHICRecent
Resultsfrom PHENIX
Strangeness (and heavy flavor) at RHIC
Recent Resultsfrom PHENIX

• Masashi Kaneta
• RIKEN-BNL Research Center
• for the PHENIX collaboration

Masashi Kaneta RIKEN-BNL Research Center
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Outlook of this talk

• PHENIX experiment

• Future strangeness and heavy flavor measurement
  at PHENIX
• Charged hadron identification at high pT Aerogel
  Cherenkov Counter
• Upgrade around vertex Silicon Vertex, Hadron
  Blind Detector, TPC
• Nosecone Calorimeter

• Summary

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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 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
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PHENIX
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Publication about Strangeness and Heavy Flavor
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Bulk Properties at RHIC

• What we learnt from RHIC?
• Low pT (lt2GeV/c) phenomena
• Thermalization
• Elliptic Flow
• Agreement with Hydrodynamical calculations
• Chemical freeze-out
• The model well describes the data and strangeness
  equilibration at RHIC
• Radial Flow
• Single spectra of p, K, p are described by common
  temperature and flow velocity
• Intermediate and high pT (gt2GeV/c) phenomena
• Dense matter effect in AuAu collisions
• High pT suppression in single particle spectra
• Back-to-Back jet suppression
• Different effect in Baryon/meson
• Mass scaling?
• Due to number of consistent quarks?
• Any difference in flavor (between light quark
  (u,d) and s)?

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Elliptic Flow
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Elliptic Flow at 62.4 GeV AuAu

• Identified particle v2 from 62.4 GeV AuAu
• Looks similar p, K, p dependence with 200GeV
  AuAu
• With more statistics, we will be able to do
  detail analyses
• Centrality dependence
• More particle species (How about L, f, etc.?)

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Elliptic flow nquark Scaling

• A scaling of number of constituent quark
• Quark coalescence picture

• 62.4GeV AuAu
• The scaling looks working like 200 GeV AuAu
• Seems to be slightly lower than 200 GeV in
  pT/nquarklt1 GeV/c

v2 /nquark
pT /nquark GeV/c
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v2 of Heavy Flavor Electrons
bin width
0.3 0.25 0.2 0.15 0.1 0.05 0 -0.05 -0.1
v2
Inclusive e v2 (statistical error only)
Heavy flavor e v2
Estimation of v2
systematic errors of estimation
work in progress
Hor. bar stat. err. Box total sys. err.
0 1 2 3 4
0 1 2 3 4
pT GeV/c

• v2 of Heavy flavor electron
• Looks consistent with/without charm flow
• We hope that run4 data will give an answer

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f meson
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f measurement at PHENIX

• Both KK- and ee- channel are available
• K? mass square from Time-of-Flight from TOF
  detector and EMCal
• e? RICH and EMCal

Run3 ?sNN 200 GeV dAu
f ? KK-
f ? ee-
Kaon ID TOF of PbSc EMCal
work in progress
work in progress
Counts / bin
Counts / bin
S 120 S/B 1/4
Invariant mass GeV/c2
Invariant mass GeV/c2
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Single Particle Spectra of f
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Inverse Slope Parameter and Yield of f

• Extracting inverse slope parameter and yield
• Using a fit function

stat. err. only
stat. err. only
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Inverse Slope Parameter and Yield of f

• Yield of f
• Increasing with ltNpartgt
• Not simple linear of ltNpartgt

• Inverse slope of f
• Flat as a function of ltNpartgt
• Over dAu and AuAu
• Within statistics systematic error

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Radial flow

• Single particle spectra of p?, K?, p,?p
• Well described by Blast wave mode (E.Schnedermann
  et al, PRC48, 2462 (1993)) fit
• Common thermal freeze-out temperature and flow
  velocity for p?, K?, p,?p
• How about for phi meson?

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Does f has same Tfo and ltbTgt with p, K, p ?

• Simultaneous fit
• The c2 contour plot for each particle

Fit range mT -mass lt 1 GeV/c2
200 GeV AuAu, 40-92
200 GeV AuAu, top 10
200 GeV AuAu, 10-40
3 s
2 s
1 s

• Within 3 s
• Overlap of f with p, K, p
• Large area of c2 contour for f
• Because of larger statistical error (i.e. smaller
  c2) of f than p, K, p
• Need more statistics to conclude

p?, K?, p,?p
p?, K?, p,?p, f
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Does f has same Tfo and ltbTgt with p, K, p ?
200GeV AuAu p, K, p PHENIX, PRC 69, 034909
(2004) f PHENIX final (to be submitted to PRC)

• Simultaneous fit by p?, K?, p,?p and f
• Seems to be common Tfo and ltbTgt
• But dont hurry up to conclude
• Again, need more statistics

Fit range mT -mass lt 1 GeV/c2
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Intermediate pT phenomena

• Energy loss effect in proton at intermediate pT
  is different from pion
• Note Those are expected to be merged at very
  high pT

(Rcp)

• Rcp of f is close to pion rather than proton
• Address a scaling of number of constituent quarks
• Statistical error is still large
• Need more statistic

pT GeV/c2
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Exotic Particle Searchin RHIC Energyat PHENIX
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Anti-Pentaquark Search
Summary table from hep-ex/0406077

• Motivation Why anti-pentaquark?
• If a particle exists, anti-particle does
• Anti-Baryon to Baryon ratio is high (gt0.7) at
  RHIC energy
• Channel
• K ?n
• PHENIX?n measurement is unique at RHIC (so far)
• Large energy deposit in EMCal
• Not photon-like shower shape
• No charged track association on the candidate
• Momentum reconstruction from Time-Of-Flight

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Reliability of Anti-n Candidate

• Anti-n momentum resolution checked
• Applying the reconstruction method to anti-proton
• Comparison of momentum from TOF and tracking
• Resolutionlt4,10,15 in pTlt1.0, 1.5, 2.0 GeV/c,
  respectively
• Momentum shift lt5

• Invariant mass peak of?S?
• ??-(1189.4) ??n ?- R.R. 99.85, c???-
  2.396cm
• ??(1197.4) ??n ? B.R. 48.31, c???
  4.434cm
• Mass shift due to no TOF calibration for ?n in
  EMCal is lt5

• Quick check by Monte-Carlo shows agreement with
  data

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K ?n in p p, dAu, AuAu
No significant signal seen
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More Strangeness at PHENIX

• From combinations of p, K, p,?p, and?n

• Blue histograms
• Pair from save event
• Red histograms
• Combinatorial back ground from event mixing from
  Min. Bias trigger
• Normalization range
• solid filled area

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Future Measurement of Strangeness and Heavy
Flavorat PHENIX
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Aerogel Cherenkov Counter

• Modules for half sector are installed in 2003
• Left half modules are already installed in July
  2004
• Enhancement of PID capability at PHENIX
• Proton separation from p/K up to p 7 GeV/c

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PID Plot with Aerogel Cherenkov Counter

• With(without) requiring Cherenkov light
  associated to the track
• We can see pion enhancement (rejection)
• It will be functional to study intermediate pT
  range

Aerogel Required (Np.e.gt3 in each PMT)
Aerogel Veto (Np.e.lt1 in each PMT)
Peak position (calibration is not perfect yet)
Statistics used for this analysis is less than 4
of total data from run4
Experimental resolution (2-sigma) line
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Upgrade Plan around Vertex

• Silicon Vertex detector and TPC
• Enhancement of momentum resolution
• Measurement of in-flight-decay particle
• Will reduce background at high pT

• Nosecone Calorimeter
• Jet measurement in forward region
• Hadron Blind Detector
• (not shown in the plot)
• Surrounds TPC
• Electron ID by Cherenkov radiation detected by a
  photocathode layer

h 2.6
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Summary
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Summary

• Elliptic flow of charged p, K, p from 62.4 GeV
  AuAu
• Similar p, K, p dependence with 200GeV AuAu
• Quark coalescence picture still works in pT
  /nquarklt1 GeV/c

• Heavy flavor electron from 200 GeV AuAu
• Consistent with/without Charm flow
• Cross section of f meson
• 200GeV dAu and AuAu
• Less ltNpartgt dependence of inverse slope
  parameter (from mT exponential fit)
• dN/dy increases with ltNpartgt, but liner scaling
• Study of blast wave model fit
• There is overlap of (Tfo, ltbTgt) of f with p, K, p
• But large range of within-3-sigma of f
• need more statistics for detail analysis
• Rcp is close to pions
• support quark number scaling not mass
• Anti-Pentaquark search at PHENIX
• No significant result in 200 GeV pp, dAu, AuAu
• With mixing-event technique, we will have the
  other strangeness
• New detectors
• Aerogel Cherenkov counters are installed
• PHENIX PID capability (proton separation from
  p/K) will be increased up to pT7 GeV/c
• Silicon VTX, HBD, TPC will come to help electron
  measurements