1.T
B
Hadronic matter
Quark-Gluon Plasma
Chiral symmetry
broken
Chiral symmetry
restored
LHC
Modelling Statistical Operator:
implementic conservation laws
canonical & grand canonical
model: comparisons with particle yields data in:
A-A, p-p, and collisions
Probing thermalisation with
fluctuations of net baryon number
model & experiment (STAR data)
Essential role of higher order moments and their ratios to probe chiral cross-over transition at LHC and RHIC
A-A collisions
fixed
x
Statistical Model Description of Particle Production in HIC
Krzysztof Redlich University of Wroclaw & EMMI GSI
2.2
Thermal nature of particle production in HIC
All properties of a thermodynamc ensemble in
thermal equilibrium are derived from part. function
To get a specific value of one fixes from
The equilibrium number of particles carrying q
3.3
+ approximate by experimentally known mass spectrum
and include finite width of resonaces
Statistical operator and mass spectrum
resonance dominance: Rolf Hagedorn
Breit-Wigner resonaces
Hagedorn mass
spectrum
4.4
3-parameters needed to fix all particle yields
Particle Yields and model parameters
Minimal setup of model parameters
To account for chemical off-equilibrium effects
introduce fugacity parameters in particle momentum distributions:
for all particles?
J. Rafelski et. al. => introduce on the quark level:
Density of hadrons composed of numbers of
u,d,s quarks gets a factor:
6-parameters needed to fix all particle yields
particle yield thermal density BR thermal density of resonances
5.5
MODEL
DATA
Hagedorn resonance gas and particle multiplicity ratios at RHIC
Particle multiplicity ratios
P. Braun Munzinger, D. Magestro, J. Stachel & K.R
Good description of particle yields, with the statistical operator of HRG formulated in GC- ensemble, in central heavy ion collisions from top AGS up to RHIC .
Problems with strangeness yields in non-central collisions at high energy and in central collisions from SIS-AGS. K – yields differ by a factor of almost 20 at SIS!
A. Andronic, P. Braun-Munzinger & J. Stachel
6.6
Kinetics of abelian charges C.M. Ko, V. Koch, Z. Lin, M. Stephanov, Xin-Nian Wang, K.R
Consider:
Rate equation
Size of fluctuations
Equilibrium limit
T,V
and
7.7
conservation on the average exact conservation
Consider thermal system with
Total Strangenes “S”=0
same suppression factor 1 for S and
S= -1
S=1
suppression increases with S and with decreasing collision energy
A
A
A
A
S
S
S
8.8
i) Strong, quadratic dependence of |S|=1 particles with at SIS ii) strange anti-particle/particle ratios independent of
KaoS (GSI-SIS)
J. Cleymans, H. Oeschler & K.R.
9.9
iii) Scaling properties of particle production yields
J. Cleymans, H. Oeschler & K.R.
Excellent description of kaon production from SIS to AGS
Scaling:
similar scaling for : A. Andronic, P. Braun-Munzinger & K.R.
subthreshold
10.10
A. Tounsi & K.R
Strangeness Enhancement from pp to AA increases with: i) strangeness content of the particleii) with decreasing collision energy
Decrease of enhancements from SPS to RHIC as predicted in the model
Consistent predictions for order of magnitude of enhancements of Omega and Xi at RHIC
Centrality dependence not correct when assuming ,however does not need to scale linearly.
Assume:
NA57
STAR
11.11
Canonical statistical model in pp collisions:
Using Canonical description of strangeness
and Grand Canonical for baryon number
and electric change conservations in p-p
collisions is a good approximation
Using correlation volume instead of
strangeness undersatuaration factor
could be equivalent: see also
I. Kraus H. Oeschler; F. Becattini et al.
P. Braun-Munzinger et al. from “QGP” 3
12.12
Canonical statistical model in pp collisions:
Using Canonical description of strangeness
and Grand Canonical for baryon number
and electric change conservations in p-p
collisions is a good approximation
LHC H. Oeschler et al.
Observed deviations from Thermal
Model predictions !!
P. Braun-Munzinger et al. from “QGP” 3
13.13
Fixing thermal parameters:
Temperature approximately independent of system size and centrality
Strong variation of baryon chemical potential with centrality and system size
for mid-rapidity data
I. Kraus et al.
p-p C-C Si-Si Pb-Pb
J. Cleymans et al.
14.Energy dependence of thermal parameters at chemical freeze-out
14
J. Cleymans et al.
A. Andronic et al.
15.Particles excitation functions in HG model
15
Braun-Munzinger, Cleymans, Oeschler &K.R.
Andronic, Braun-Munzinger &Stachel (09)
Nu Xu & K.R. H.Oeschler et al.
Problem with canonical description of HADES data: data deviate by factor five from model predictions!!
HADES
16.The Yields of anti-hypernuclei at RHIC
First observation of hypernuclei 1952
by Danysz and Pniewski
First observation of anti-hypernuclei by STAR in AU-AU coll.
Can we understand yields within the SM?
16
Statistical Model Results
Coalesence Model Results
N. Sharma et al., A. Andronic et al.
17.Charm production in annihilation
17
Jet structure of hadrons production
Flavor content of the jets:
Can we quantify light and heavy flavor particles within Statistical Model ??
18.18
Most hadronic events in high energy e+e collisions are two-jet events
Each jet represents an independent fireball
2-jets with
2-jets with sub. decays of “C” and “B”
Problem: Open Charm and Bottom
shows dramatic deviations from data
Subtract the contributions from
charm and bottom to lighter particles
e.g. C,B contributions to
19.19
Canonical effects and charm/bottom mesons
Total charge of the system
And small
Strong Suppression of thermal
particle phase-space
Strong Enhancement of thermal
particle phase-space
Charge of the system
Charge of the particle
20.20
Charm and Bottom particles at LEP, 91 GeV
Open charm and bottom well described by thermalisation of thermal fireball with
overall Charm= and Bottom=
and are entirely coming from Bottom’s decays and agree with model
Hidden charm, Y is of non-thermal origin, thus, it does not fit to model systematic!
21.Production cross section of relative to
21
Data pA compilation by:
A. Andronic, F. Beutler, P. Braun-Munzinger, J. Stachel &K.R.
The ratio for the Tevatron energy was derived
from the CDF data on and
and is for :
We have extrapolated the measurements
from down to
Strong suppression of ratio
in relative to
different production mechanism in
elementary and heavy ion collisions
The nuclear modification canceled
out in the ratio as the pp
value is the same as in the pA
Good agreement of Statistical Model
and data in PbPb collisions
RHIC
CDF
NA50
22.STAR DATA ON MOMENTS of FLUCTUATIONS
Mean
Variance
Skewness
Kurtosis
Phys. Rev. Lett. 105, 022302 (2010)
23. Properties of fluctuations in HRG
Calculate generalized susceptibilities:
from Hadron Resonance Gas (HRG) partition function:
and
resulting in:
Compare this HRG model predictions with STAR data at RHIC:
F. Karsch & K.R.
and
24.Comparison of the Hadron Resonance Gas Model with STAR data
Frithjof Karsch &K.R. K.R.
RHIC data follow generic properties expected within HRG model for different ratios of the first four moments of baryon number fluctuations
Can we also quantify the energy dependence of each moment separately using thermal parameters along the chemical freezeout curve?
25.Mean, variance, skewness and kurtosis obtained by STAR and rescaled HRG
STAR Au-Au
STAR Au-Au
these data, due to restricted phase space:
Account effectively
for the above in the HRG model
by rescaling the volume
parameter by factor 1.8/8.5
26.QCD phase boundary & Heavy Ion Data
QCD phase boundary appears near freezeout line
Particle yields and their ratios, well described by the Hadron Resonance Gas
Thus: HRG has to be a good description
of regular part of QCD partition
function in hadronic phase
Thus: HRG has to describe LGT
thermodynamics
27.Kurtosis as an excellent probe of deconfinement
HRG factorization of pressure:
consequently: in HRG
In QGP,
Kurtosis=Ratio of cumulants
excellent probe of deconfinement
S. Ejiri, F. Karsch & K.R.
Kurtosis
F. Karsch, Ch. Schmidt
The measures the quark
content of particles carrying
baryon number
28.Higher moments of baryon number fluctuations
28
If freeze-out in heavy ion collisions occurs from a thermalized system close to the chiral crossover temperature, this will lead to a negative sixth and eighth order moments of net baryon number fluctuations.
These properties are universal and should be observed in HIC experiments at LHC and RHIC
J. Engels, F. Karsch, B. Friman, V. Skokov & K.R.
Figures: results of the PNJL model
obtained within the Functional
Renormalisation Group method
29.Fluctuations of 6th and 8th order moments exhibit strong variations from HRG results: Their negative values near chiral transition to be seen in heavy ion collisions at LHC and RHIC
29
The range of negative fluctuations near chiral cross-over: PNJL model results with
quantum fluctuations being included : These properties are due to O(4) scaling ,
thus should be also there in QCD.
30.30
Conclusions
The Hagedorn partiction function of the Hadron Resonance Gas is a very good approximation of the regular part of the QCD partiction function:
=> it reproduces bulk of particle yields meassured
form SIS up to LHC energy
=> it reproduces net proton fluctuations up to 4th order
measured at RHIC
=> It reproduces fully ratios of different
susceptibilities obtained on the lattice
=> it reproduces thermodynamics up to very near
T_c obtained on the lattice for different quark
masses
The 6th and 8th order moments of baryon number fluctuations are excellent probes of chiral cross-over transition in HIC at the LHC and RHIC
31.31
Centrality dependence of baryon chemical potential
For NA57 the temperature is fixed to from central
Pb-Pb collisions: ( the value consistent with recent analysis of A. Andronic et al.)
32.32
Strangeness enhancement from p-Be to central Pb-Pb collisions at
Canonical model with exact strangeness conservation at fixed
and being centrality dependent provides good description of NA57 data if the
correlation volume scales as:
33.33
Multistrange particle enhancement at RHIC
Calculations done at fixed , (Nu Xu et al.) for all centrality
Overall agreement is not satisfactory, particularly for Lambda yields