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J. Cleymans I. Kraus H. Oeschler K. Redlich. Does Hadronization happen via Cluster formation?. SQM2008, Beijing, Oct.7th, 2008. Chemical Freeze Out. J. Cleymans and K. Redlich, PRL 81 (1998) 5284. NA49 Data - 158 AGeV. Ingrid Kraus et al., Phys. Rev. C76 (2007) 064903.
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J. Cleymans I. Kraus H. Oeschler K. Redlich Does Hadronization happen via Cluster formation? SQM2008, Beijing, Oct.7th, 2008
Chemical Freeze Out J. Cleymans and K. Redlich, PRL 81 (1998) 5284
NA49 Data - 158 AGeV Ingrid Kraus et al., Phys. Rev. C76 (2007) 064903 Corr. vol. NOT prop to Apart
Canonical Suppression (SHM) Pion density n(π) = exp(-Eπ/T) Strangeness is conserved! Kaon density NN N Λ K+ n(K) = exp(-EK/T) [g V∫ … exp[-(EΛ-µB)/T] J. Cleymans, HO, K. Redlich, PRC 60 (1999)
Canonical Suppression can./grand can. ΔS=1 ΔS=3 Example: T = 170 MeV μB = 1 MeV Values for LHC
Three options for SHM calculations: • Canonical with R given by system size • Additionally strangeness suppression via γs • Canonical suppression is controlled by RC which can differ from the system size R (cluster!) R I. Kraus, J. Cleymans, H. O., K. Redlich, System size: Phys. Rev. C76 (2007) 064903 RC
System size (and energy dep.) of cluster size RC= R • A+A: clusters smaller than fireball • RC not well defined for RC ≥ 2 fm because suppression vanishes Pb+Pb Au+Au
For heavy systems possibly the correlation volume extends over about 2-3 fm. Then no canonical suppression can be observed in the particle ratios!
Same three options for pp collisions: • Canonical with R given by system size • Additionally strangeness suppression via γs • Canonical suppression is controlled by RC which can differ from the system size R (cluster!) R I. Kraus, J. Cleymans, H. O., K. Redlich, pp: arXiv:0808:0611 RC
p+p T = 165 MeV, μB = 14 MeV b)γS~ 1 c)RC~ R = 1.3 fm T = 165 MeV, μB = 220 MeV b)γS = 0.7 c) RC = 1.0 ± .3 fm, R = 1.4 fm I. Kraus et al., arXiv:0808.0611
Predictions for pp at LHC Prediction for heavy ions: Grand can. I. Kraus et al., PRC 74 (2007) 034903
Predictions for T = 170 MeV and μB = 1 MeV I. Kraus, J. Cleymans, H. O., K. Redlich, arXiv:0808:0611
? Answer is a few months from ALICE!!! STAR nucl-ex.0808.2041
News on the ϕ Puzzle Statistical Hadronization Model: S = 0 -> no canonical suppression for ϕ Strangeness undersaturation: Suppression goes with (γs)ns with nS = 2
S = 2 ϕ S =1 J.H.Chen (STAR) QM2008,nucl-ex0804.4363
S = 0 R = 1 S = 2 R as (K/π)2 I. Kraus, et al., Phys.Rev. C76 (2007) 064903
central collisions, heavy systems ϕ/K- is rather constant with √s!
System-size dependence not explained as canonical effect, if size prop. to Apart . Cluster concept describes data! As well as γS does. May be also in very heavy systems clusters, as R above 2-3 fm grand-canonical behavior. Cluster size in pp collisions R = 1 – 1.3 fm. Does R increase with √s? ϕ/K- always around 0.16, but higher at 1.7 AGeV (0.38±0.13) In agreement with canonical description with s(ϕ) = 0
The ϕ Puzzle • At high energies quark content seen, but the effective strangeness content ? • At low energies, SHM seems to work, ignoring the s content of the ϕ but what is its justification?
STAR Coll., PRL 99 (2007) 112301
Does Hadronization happen via Cluster formation? Partcile Production from SIS to the LHC J. Cleymans, I. Kraus, H. Oeschler, K. Redlich Beijing, Oct.7th, 2008
What is the strangeness content of the ϕ? • Data from SPS centrality dependence in PbPb • System size dependence pp, CC, SiSi • Data from RHIC AuAu • New results from 1 – 2 AGeV SIS