Sean Gavin Wayne State University

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Sean Gavin
Wayne State
University
Strange Disoriented Chiral Condensates

• Chiral Restoration? DCC ? pion fluctuations
• but QCD has more than two flavors

• I. DCC with 3 flavors correlations of Ks0 and
  K? S.G. J.I. Kapusta
• strange correlations from n DCC domains
• robust observables, thermal background
• II. conventional kaon isospin fluctuations M.
  Abdel-Aziz S.G.
• wounded nucleons, HIJING, UrQMD
• isospin fluctuations probe models

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Strange Isospin Fluctuations Why?

• 2 1 flavor QCD transition depends on strange
  quark mass
• theory Pisarski Wilczek Gavin, Gocksch
  Pisarski
• lattice Brown et al. Schmidt, Karsch
  Laermann
• Kapusta Wong
• SPS ?? ? enhancement explained by many small
  strange DCC?
• topological baryon production Ellis, Heinz
  Kowalski
• ? model of chiral symmetry breaking Kapusta
  Srivastava
• Polyakov Loop Condensate model of confinement?
• many small domains ? RHIC pT fluctuations
  Pisarski Dumitru
• K/? enhancement Scavenius, Dumitru Lenaghan
• consequence small strange domains ? kaon
  fluctuations

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21 flavors ? Kaon Fluctuations?

• QCD chiral symmetry broken by condensate below
  Tc
• condensate for two light flavors
• neutral v. charged pion fluctuations
• ?? neutral pion fraction
• u, d strange quark
• pion and kaon fluctuations
• ?K neutral kaon fraction
• Randrup Schäffner-Bielich

fp
1/3
fK
1/2
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Kaon Isospin Fluctuations
S.G. J.Kapusta

• measure Ks0 and charged K
• characterize fluctuations of fK N0/ Ntot by
  variance
• single kaon DCC
• uncorrelated thermal source

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Dynamic Isospin Fluctuations

• experiment measure Ks0, K with different
  efficiencies
• efficiency ? measured/observed multiplicities
• STAR ?0 10-20 for Ks0 ltlt ?c 70 for K
  
• dynamic isospin fluctuations
• robust independent of efficiencies ?
  Pruneaus talk
• C. Taylor et al Pruneau, Gavin and Voloshin
• vanishes for thermal sources, uncorrelated
  sources

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Many Small Domains

• SPS ?- ? data ? many domains, size 2 fm
  Kapusta Wong
• WA98 no big pion signals resolved
• ? model predictions S.G., Gocksch Pisarski,
  
• n pion domains Amado Lu Chow Cohen
• n kaon domains S.G. Kapusta
• Gaussian for n gt few
• variance

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DCC Thermal Source

• S.G. J.Kapusta
• fraction ? of DCC kaons
• variance
• dynamic fluctuations
• only DCC contributes
• can be positive or negative
• ASK what about non-equilibrium effects?
  

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Conventional Isospin Fluctuations
Abdel-Aziz S.G.

• AA collision superposition of NN subcollisions
• nonequilibrium fluctuations in rapidity interval
• NN level string fragmentation, resonances
• AA changes rescattering, resonance abundance
• pp simulations
• wounded nucleon model, M participants

preliminary
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HIJING Dynamical Fluctuations
HIJING simulations for AuAu at 200 AGeV
-0.5 lt y lt 0.5 Wounded nucleons
ok agreement with wounded nucleon
model ?dyn different for
Abdel-Aziz S.G.
Kch Ks0
K Ks0
K? Ks0
participants, M
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Isospin Fluctuations Probe Models
same charge fluctuations for HIJING, UrQMD AuAu
at 200 AGeV, -0.5 lt y lt 0.5 different isospin
fluctuations
? ? ?
KK?
participants
Abdel-Aziz S.G.

• UrQMD ? HIJING
• ? wounded nucleons
• different signs for KchKs0
• same sign for all centralities

participants
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DCC from Collisions
threshold for DCC onset take
for b0 6 fm, 10 DCC, 0.5 lt y lt
0.5 dynamic fluctuations sensitive to
DCC signal sign change compare to
??????? not sensitive
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Summary Observing Kaon Fluctuations

• Ks0 K? correlations test 21 flavor DCC? S.G.
  Kapusta
• SPS ? data ? many small strange DCC?
  Kapusta Wong
• small domains from Polyakov loop condensate
  Pisarski Dumitru
• Robust observables compare unlike particles
• charged particles, baryons Pruneau, Voloshin
  S.G.
• kaon fluctuations
• Dynamical isospin observable
• dynamic fluctuations shows DCC effect
• distinguishes conventional dynamical models
  unlike charge fluctuations Abdel-Aziz S.G. (in
  progress)