qcd phase diagram, phase transition and fluctuations
DESCRIPTION
QCD Phase Diagram, Phase Transition and Fluctuations. Bedanga Mohanty Physics group, VECC, Kolkata. STAR Preliminary. First observation of anti-hypertriton Relevant to physics of neutron star. QM09 : J. Chen. Heavy Ion Collisions. Experimentally possible. Explore the QCD phase diagram. - PowerPoint PPT PresentationTRANSCRIPT
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QCD Phase Diagram, Phase Transition and Fluctuations
Bedanga MohantyPhysics group, VECC, Kolkata
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Heavy Ion Collisions
Explore the QCD phase diagram Experimentally possible
Supported by theory
F. Karsch, Prog. Theor. Phys. Suppl. 153, 106 (2004)
J. D. Bjorken Physical Review D 27 (1983) 140
USA-NSAC 2007 Long-range PlanSTAR Preliminary
QM09 : J. Chen
First observation of anti-hypertritonRelevant to physics of neutron star
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Phase StructureHadronic Quark Gluon
T < Tc : Confined T > Tc : De-confined
Expectation value of the Polyakov Loop : < L > ~ limit(r--->0) e-V( r) ~ 0
<L> > 0
Chiral condensate : < > = 0 < > ~ 0
B = 0 Spontaneous Z3 breaking
Chiral symmetry restored
B > 0
E. Laerman, O. Philipsen Ann. Rev. Nucl. Part. Sci. 53, 163, 2003
K. Rajagopal and F. Wilczek, Handbook of QCD
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At QM2009
Search for the Critical Point of Strongly Interacting Matter in NA49 -- K. Grebieszkow
Experimental study of the spontaneous strong parity violation -- S. Voloshin
Fluctuations of Conserved Quantities Using Higher Order Moments in STAR Experiment -- T. Nayak
p/ fluctuations in Au+Au collisions- G. Westfall
Search for QCD critical point .. kurtosis of net proton in STAR experiment - B. Mohanty
p/ fluctuations in Au+Au collisions- J. Tian
SPS low-energy scan / FAIR prospects -- C. HoehneThe NA61/SHINE Experiment at the CERN SPS- A. Laszlo Bulk properties at 9.2 GeV in STAR - L. Kumar
CBM at FAIR - J. M. Heuser
Probing the QCD Phase Diagram with Chiral Effective Models -- C. Sasaki
Critical Points in the QCD Phase Diagram with Two Flavors of Quarks -- J. Kapusta
The Quarkyonic Phase Transition and the FPP-NJL Model in Large and Finite Nc -- L. McLerran
Parity violation in Hot QCD -- D. Kharzeev
The Chiral Critical Surface of QCD -- O. Philipsen
QCD Transition Temperature: Approaching the Continuum on the Lattice -- Z. Fodor
Critical Point in Finite Density Lattice QCD by Canonical Approach -- Shinji Ejiri
Fixed Scale Approach to the Equation of State on the Lattice -- Kazuyuki Kanaya
The Lattice QCD Equation of State and implications for Hydrodynamic Modeling of Heavy Ion Collisions -- R. Soltz
Finite temperature latice QCD : Present status -- P. Petreczky
QCD critical point using canonical ensemble - A. Li
Non-Gaussian Fluctuations Near the QCD Critical Point -- M. Stephanov
Higher Moments of Charge Fluctuations in QCD at High Temperature -- C. Miao
Signals of the QCD Critical Point in Hydrodynamic Evolution -- C. Nonaka Critical opalescence - T. Kuihiro
Continuum limit of Gloun plasma - S. Gupta
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Part - 1
Lattice QCD results at B ~ 0Experimental results on fluctuations and charge correlations
Before these, few things to keep in mind regardingLattice results …
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Lattice QCD
(A) Quantum statistical ensemble in thermal equilibrium Simulate : Z = Tr exp(-H/T)
Temperature change : Usually fix Ntvary “a” (g : lattice gauge coupling)
(D) Different approach by QM09 : K. Kanaya“T integral method”T varied by Nt at fixed “a”
T. Umeda et al., arXiv : 0809.2842
Setting quark massesLines of constant Physics - m/m = const
(E)
Number of quark flavours : 2+1 flavour with mu = md and ms
aNt ~ 1/Ta : Lattice spacingN : Sites in imaginary timeT : Temperature
Reality = continuum limitSmaller “a”, larger Ntat fixed T(B)
(C) Lattice Action Smaller Nt - distortions due to cutoff effectsEOS computation cost ~ a-11
QM09 :P4 : S. EjiriNaik and P4 : R. Soltz
P. Hegde et al, Eur. Phys. C55, 423 (2008)
Spatial volume also important
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Order of Phase Transition for B ~ 0
Y. Aoki et al., Nature443:675-678,2006
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Physical quark massesContinuum limitSimulations along Lines of Constant Physics mK/m = 3.689; fK/m = 1.185Staggered fermionic action
No significant volume dependence (8 times difference in volumes)Phase transition at high T and = 0 is a cross over
T grows with 6/g2, g : gauge coupling
1st order : Peak height ~ V Peak width ~ 1/VCross over : Peak height ~ const. Peak width ~ const.2nd order : Peak height ~ V
Lattice results on electroweak transition in standard model is an analytic cross-over for large Higgs mass
K. Kajantie et al., PRL 77, 2887-2890,2006
Relevant to LHC and current RHIC regimes
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Transition Temperature
Point of sharpest change in temperature dependence chiral susceptibility, the strange quark number susceptibility and the renormalized Polyakov-loop
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Possible sources of differences : (a) Ambiguity in locating Tc for cross-over; (b) Physical observable used to set the scale (r0, fK); (c ) Preferred renormalization of chiral susceptibilities(d) Use Wilson fermions
QM09 : Z. Fodor R. Soltz
De-confinementTC ~ 175 (2)(4) - 192 (7)(4) MeV - 185 - 195 MeV
Chiral and deconfinement same T or different T ?
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Transition Temperature
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Consequence for heavy-ion phenomenology both at LHC and RHIC:
~ T4; Results in ~ 60% in difference energy density at TC
F. Karsch : Lattice 2007
V. G. Bornyakov et al, POS Lat2005, 157 (2005)Y. Maezawa et al, hep-lat/0702005 C. Bernard et al, Phys. Rev. D 71, 034504 (2005)M. Cheng et al, Phys. Rev. D 74, 054507 (2006)Y. Aoki et al, Phys. Lett. B 643, 46 (2006); 0903.4155
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QM08 :S. Gupta
Lattice : Equation Of State
gparton ~ 47.5
g ~ 3
~ g (2/30)
15% deviation from Ideal gas at 4TC
Calculations with larger spatial volumes ?
Agreement with perturbation theoryConsistent with Stefan-Boltzmann limit
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G. Endrodi et al., PoS LAT2007:228,2007
QM09: P. Petreczky
R. Soltz Important for heavy ion phenomenology (T 1/cs2 const
M. Cheng et al., Phys. Rev. D 77, 014511 (2008)
Velocity of sound
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Fluctuation : Deconfinement TransitionFor a thermodynamic system
(pT)2/pT2 ~ (T)2/T2 = 1/Cv
(N)2/<N> ~ 1/
Second moment of event-by-eventdistributions of multiplicity, mean pT, ET after removing non-dynamical fluctuations.
General approach
Fluctuation in experimental observables related to thermodynamic quantities
Fluctuations in particle ratios -- Sensitive to particle numbers at chemical FO not kinetic FO-- Volume effects may cancel
S. Jeon, V. Koch, PRL 83, 5435 (1999)
Fluctuation in conserved quantities : net charge,net baryon number, net strangeness-- Related to corresponding susceptibilities-- Given strong longitudinal expansion, fluctuations in QGP may be preserved during hadronisation-- Conservation laws limit their dissipation
S. Jeon, V. Koch, PRL 85, 2076 (2000)M. Asakawa, U. W. Heinz, B. Muller
PRL 85, 2072 (2000)
~ NaivelyL. Stodolsky, PRL 75,1044 (1995)
S. Mrowczynski, PLB 430, 9 (1998)
<(E)2> ~ T2Cv(T)M. Stephanov et al., PRD 60, 114028 (1999)
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Fluctuation Measures
Observable Definition Non-dynamical Experiments
x x2/<N>
Scaled variance
Beyond poissionian (>1) Other models without PT
WA98, NA49, PHENIX
pT zpT = (pTi - <pT>); ZpT = zpT
Sqrt(< ZpT 2 >/<N>) - Sqrt(zpT
2)
= 0 by construction NA49,PHENIX
dyn < Nx (Nx - 1)>/<Nx>2 + < Ny (Ny - 1)>/<Ny>2
- 2 <NxNy>/<Nx><Ny>
= 0 by construction STAR
FpT data - baseline )/ baseline Baseline : Mixed events PHENIX
pT X2dyn (data) - (inclusive single particle)
= sgn(X2dyn) Sqrt(| X2
dyn |)/<pT>
= 0 by construction CERES
<p T,ip T,j> = 0 by construction STAR, CERES
x,dyn
pt
~ sign(2(data) - 2(mixed))Sqrt(|2(data) -
2(mixed)| )Mixed events STAR
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Dominantly looking at second moment, constructions motivated for removing non-dynamical fluctuations
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Ratio Fluctuation Results
Observable Experiment (Beam energy in GeV)
Conclusions
K/ and p/ NA49(6.3 - 17.3)
arXiv:0808.1237
M.I. Gorenstein et al, arXiv:0811.3089
p/fluctuations : similar results from UrQMD
K/ higher than UrQMD at lower energy
HSD transport gives similar energy dependence
K/ and p/ STAR(19.6 - 200 GeV)
arXiv: 0901.1795
G. Westfall - WWND09
K/ : Statistical hadronisation model (q>1) agrees. HSD transport model similar results
p/fluctuations similar to default UrQMD
QM09 : G. Westfall
STAR : arXiv : 0901.1795 p/Kp/
K/QM09 : J. Tian
QM09 : V. Konchakovski
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Conserved Quantity Fluctuation Results
Observable Experiment (Beam energy in GeV) Conclusions
Net-charge STAR (19.6 - 200 GeV) p+p, Cu+Cu, Au+Au arXiv:0807.3269
Lie between charge conservation effects and resonance gas model.
Net-charge NA49 (6 - 17 GeV) PRC 70,064903 (2004)
Consistent with charge conservation
Net-charge PHENIX (130 GeV)
PRL 89, 082301 (2002)
Similar to RQMD calculations.
STAR
Mostly fluctuation in net-charge has been studiedPHENIX
NA49
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Experimental : Possible Deconfinement Observables
PHENIX : direct photon arXiv:0804.4168
Tinitial > TC (Lattice)initial > C (Lattice)
QM09 : Y. Xu
Observables from SPS indicating possible phase transition was discussedin C. Hoehne Plenary Talk
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Discussion
Why we do not see fluctuations reflecting QGP to hadronic phase transition -
Is Relaxation > hadronic
This leads to the issue of acceptance needed to measure the primordial fluctuations
One possibility is dissipation of fluctuations
M.A. Aziz et al, PRC 70, 034905 (2004)E.V. Shuryak et al, PRC 63, 064903 (2001)B. Mohanty et al, PRC 67, 024904 (2003)
ymin > ycoll (mean change in rapidity due to collisions)~ (diffusion coefficient) free (mean free time)
What is the expectation for a cross-over phase transition ?
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Chiral Magnetic Effect
Topological structure of QCD vacuum -- Parity violations in strong interactionsD.E. Kharzeev et al, NPA
803, 227 (2008)Assume quark are mass less : (Helicity/Chirality)R.H quarks & anti-quarks : s and p same directionL.H. quarks & anti-quarks : s and p opposite direction
Mass less quarks can change chirality by interacting with gluons. Axial Ward Identity relates chirality to properties (topology) of gluon fields.
N L,R : total number of Left/Right handed q+qbar
of a particular flavour
u : Positive charged : negative charge
If one observes a difference between NL and NR clear indication of parity violations
But how do we experimentally distinguish L.H and R.H quarks (we detect hadrons)
Polarization in magnetic field ?
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For finite volume : Charge difference in upper and lower hemisphereQM09 : D. Kharzeev
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Chiral Magnetic Effect
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Topological structure of QCD vacuum -- Parity violations in strong interactions. S. Voloshin
PRC 70, 057901 (2004)Heavy ion collisions :Possibly we have produced a de-confined quark-gluon matter.Large magnetic field in the direction of angular momentum.Charge separation can take place along this direction.Angular momentum is perpendicular to reaction plane.Look for charge asymmetries.
Charge asymmetry observed in STAR experiment. Investigations so far indicate they could only be consistent with parity violation effects in strong interactions.
De-confined phase neededChirally symmetric phase needed
K. Fukushima et al, PRD 78, 074033 (2008)
Parity evenPhysical background
QM09 : S. Voloshin
STAR Preliminary
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Part - 2
QCD Critical Point
Thermodynamic quantities ~ correlation length
Critical exponents, are universal, depend on degrees of freedom in the theory and their symmetry, no dependence on details of interactions.
Different physical systems == same universality class
For example : Liquid-Gas system critical point and QCD critical point Same universality class : Z2
Critical Opalescence as observed in CO2 liquid-gas transition
T. Andrews. Phil. Trans. Royal Soc., 159:575, 1869
T > TC T~TC T < TC
Long range correlations, density fluctuations
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First Order Phase Transition (B > 0)
QM09 : S. EjiriPRD 78, 074507 (2008)
μ∗q /T is the chemical
potential that gives a minimum of the effective potential
First order phase transition for T/Tc < 0.83 and q/T > 2.3Existence of critical point suggested
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Canonical ensemble usedM = 770 MeV
Nf = 2P4-improved staggered quark action
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Critical Points : Linear model with quarks
QM09 : J. Kapusta
Aim : Study phase diagram of Linear model coupled to two light flavour quarks of same massIncludes thermal fluctuations of meson and fermion fieldsVacuum pion mass varied : 0 to 300 MeV(Can compare to Lattice studies)Studies at non-zero chemical potential
Constants in the modelPion decay constant f = 92.4 MeV mass (m)= 700 MeVMass of quark = 313 MeVm varied : 0 - m/2
Phys.Rev.C79:015202,2009
Conventional picture
No phase transitionFor m,vac > 321 MeV
Exotic pictureTwo critical points
QM09 : C. Sasaki
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QCD Models : Critical Point
Model/Approach (TE, E )MeV Work
Nambu-Jona Lasinio (NJL) Model
(40,1050),(55,1440)
(46,996),
(101, 633)
Asakawa, Yazaki 1989
Scavenius et al 2001
Berges, Rajagopal 1998
Linear-model (93,645) Scavenius et al 2001
Ladder QCD (Cornwall, Jackiw, Tomboulis - CJT effective potential)
(95, 837) Hatta, Ikeda 2002
Random Matrix Model (120,700) Halasz, et al (1998)
Statistical bootstrap principle (171,385) Antoniou, Kapoyannis 2002
Need first principle calculations - Lattice
QM09 : C. Sasaki
Compilation by Mikhail Stephanov
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Lattice : QCD Critical Point
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Expectation value of an observable M : Dirac MatrixSG : Gluonic action
Issue for non Zero , Det M is not positive definite-- Sign problem
Four approaches
Reweighting : Z = < e -S() det D() / e-S(0
) det D(0) >=0
Taylor expansion of thermodynamic observables in /T about = 0 Imaginary chemical potential : imaginary, fermion determinant positive Canonical ensemble - predicts existence of QCD critical point
For > 0 the quark determinant becomes complex
(TE ~ 160 MeV and E ~ 600 MeV, m ~ 700 MeV) QM09 : A. Li
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Lattice : QCD critical pointReweighting
Z. Fodor and S.D. Katz JHEP 0404, 50 (2004)
TE = 162 +/- 2 MeVE = 360 +/- 40 MeV
Imaginary Chemical PotentialP. De Forcrand and O. Philipsen PoS LATTICE2008, 208 (2008)
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nf = 2+1 continuum limit ?Spatial volume, stable results for different Nt ?
QM09 : Owe Philipsen
Taylor ExpansionR. Gavai and S. Gupta Phys. Rev. D 78, 14503 (2008)
TE/TC = 0.94 +/- 0.01 E /TE = 1.8 +/- 0.1
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Signature of QCD Critical Point : Higher Moments
At Critical point < (N)2> ~ 2
= Correlation length
Value limited in heavy-ion collisions Finite size effects < 6 fm Critical slowing down, finite time effects ~ 2 - 3 fm (model assumptions)
Challenging to measure
Experimentally : Look for non-monotonic variation of higher moments of multiplicity distributions and mean pT distributions as a function of beam
energy
B. Berdnikov & K. Rajagopal, Phys. Rev. D 61, 105017 (2000)Stephanov, Rajagopal, Shuryak, Phys. Rev. D 60, 114028 (1999)
< (N)3> ~ 4.5
< (N)4> - 3 < (N)2>2 ~ 7
M. A. Stephanov, Phys. Rev. Lett. 102, 032301 (2009)
Higher Moments
Higher sensitivity as stronger dependence on
Non Gaussian features increase if the system freezes-out closer to QCD Critical point
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Signature of QCD Critical Point : Net protons
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Net Proton number is sufficientConnection between Lattice and Experimental data possible
M. Cheng et al., arXiv: 0811.1006
Equilibrium thermodynamic system
Q = B/2 + I3
Q ~ (1/VT) < (Q)2> = (1/4) B + I
~ (1/VT) < (Np-pbar)2>
Net Proton number fluctuations ~ singularity of the charge and baryon number susceptibility-iso-spin blindness of field
Y. Hatta and M. A. Stephanov, Phys. Rev. Lett. 91, 102003 (2003)
Divergence of susceptibilities at Tc
Susceptibilities are related to higher moments of multiplicity observables.Also seen in QCD model based calc.
QM09 :Chuan Miao
QM09 : C. Sasaki
B = 0
S. Gupta
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Experimental Results on Higher Moments
F2 = (2 - <N>)/<N>2
First look at net-protons First look at higher moments
Monotonic behavior observedWe are probing a small B region
QM09 : T.K. Nayak B. Mohanty
Setting the baseline for the futureQCD critical point search program
Net Protons
Npart
STAR Preliminary
STAR Preliminary
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Signature of QCD Critical Point : pbar/p
The presence of a critical point deforms the isoentropic trajectories (S/nB = constant)
The critical point serves as an attractor of the hydrodynamical trajectories.
Below TC :Both T and B decrease for critical point B remains fairly constant for others trajectories
Experimentally observable : Drop in pbar/p vs. pT (Coalescence region)Provided nucleons of high pT are chemically frozen out earlier - supported
by UrQMD simulations
QM09 : C. Nonaka
M. Asakawa et al, PRL 101, 122302 (2008)
pbar/p ~ exp (-2B/T)
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Experimental Results on pbar/p vs. pT
Fitting Procedure : y = a (mT - m) + b
Slope vs. Beam Energy/B
No large drop in ratio observed for intermediate pT range
Phys. Rev. C73, 044910 (2006)Phys.Rev. C78, 034918 (2008)
QM09 : K. Grebieszkow
STAR : PLB 655, 104 (2007) PRL 97, 152301 (2006)
STAR
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Signature of QCD Critical Point : Disappearance of Mach Cone
Experimentally : Disappearance of mach cone like signals
QM09 : Teiji KunihiroStudy focused on critical dynamics around QCD critical point with relativistic dissipative hydrodynamics
Uses the idea of coupling the density fluctuations to thermal energy
At the soft mode around QCD critical point is the thermally induced density fluctuations (Rayleigh peak) and the sound modes get suppressed (Brillouin peak)
STAR : Phys. Rev. Lett. 102, 052302 (2009)
Rayleigh peak
Brillouin peak Brillouin peak
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SPS Fluctuation Results on QCD Critical Point
Assuming correlation length 3-6 fm and experimental acceptances
QM09 : K. Grebieszkow
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Critical Point ?
B ~ 250 MeVT ~ 178 MeV
No signature for energydependenceSystem size dependence shows a jump
Stephanov, Rajagopal, Shuryak, Phys. Rev. D 60, 114028 (1999)Hatta, Ikeda Phts. Rev. D 67, 014028 (2003)
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Part - 3
New Phase of QCD
New Experimental Programs
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New Phase of Matter in Large Colour Limit
In the limit of large number of colors (Nc)
There could exist three phase of matter
Confined phase
De-confined phase
Quarkyonic phase
Matter has and p that of a gas of quarks yet confined. (O(Nc))
Order parameter
Baryon number
QM09 : L. McLerran
Experimental signature :Baryon-Baryon correlations to look for nucleation of baryon rich bubbles surrounded by baryon free regions
QM09 : P. Sorensen & A. Mocsy
QM09 : C. Sasaki
RHIC
LHCSPS
FAIR
AGS
Confined
No Baryons
N ~0(1)
Not Chiral
Confined
Baryons
N ~ NcNf
Chiral
Debye Screened
Baryons Number
N ~ Nc
Chiral
2
Color SuperconductivityLiquid Gas
Transition
Critical Point
Baryon energy density ~ Meson energy density
Quark Gluon Plasma
Quarkyonic Matter
Confined Matter
T
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Conjectured Phase Diagram for Nc = 3
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New Program : Explore QCD phase diagram
Looking for onset of various observationsAu+Au 200 GeV
Pb+Pb 17.3 GeV
Baryon-meson differencemeson will play a crucial role
Jet quenching
Chiral Magnetic effect
QM09 : S. Shi
WA98 : PRL 100, 242301 (2008)
PHENIX : PRL 101, 232301 (2008)
QM09 : S. Voloshin
STAR Preliminary
Partonic collectivity
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New Program : Look for QCD critical point
Most lattice calculation predicts critical point B > 160 MeVCurrent studies at RHIC probes B ~ 14 -60 MeV
Need a beam energy scan program - but fixed target experiments were there ..
R.V. Gavai and S. Gupta, Phys.Rev.D71:114014,2005
Cross over
QCD critical point
Hadrons
1st order
QGP
The real voyage of discovery consists not in seeking new lands but seeing with new eyes.-- Marcel Proust, French novelist, 1871-1922.
At RHIC
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RHIC Critical Point Search Program - Advantage
Uniform acceptance for different particle species and for different beam
energies in the same experimental setup (advantage over fixed traget expt.)
Hadron Mass
Bea
m E
nerg
y
200 GeV
62.4 GeV
9.2 GeV
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RHIC Critical Point Search Program - Advantage
Collider experiment : Variation of particle density withbeam energy slower. Occupancy in detectors reasonable
compared to fixed target experiments at similar collision energy
G. Roland
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RHIC - Collider Demonstrated Capabilities
All setup worked very well with RF harmonic number 366
Defocusing sextupole reversal and octupole improved blue lifetime by factor 4
~ 50-60% injection efficiency
STAR collisions about 13h after 1st beam and PHENIX about 24h after 1st beam
Experiment useful event rates 0.7-1Hz with 56 bunches.
Maximum luminosity 3.5 1023 cm-2s-1 Average luminosity 1.2 1023 cm-2 s-1
Factor of 3 increase in luminosity easily achievable
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RHIC - Experiments Demonstrated Capabilities
These results from the lowest beam energy collisions at RHIC demonstrate experiment’s readiness to take up the proposed Beam Energy Scan Program.
Large and uniform acceptance for all beam energies in a collider set up, excellent particle identification (TPC+TOF) and higher statistics will provide ideal data to experimentally measure fluctuations/Kurtosis to locate QCD critical point
Results with only 3000 events ! QM09 : L. Kumar
STAR Preliminary
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RHIC Critical Point Search - Future Plans
Run Number 9071097
First paper from RHIC was based on ~ few thousand events; PHOBOS : PRL 85 (2000) 3100
“The measurements shown here represent the first step toward the development of a full picture of the dynamical evolution of nucleus-nucleus collisions at RHIC energies.”
The results shown at QM2009 from RHIC low energy test running :“These measurements shown here could become the first step towardsa detailed study of the QCD phase diagram at RHIC”
Experiments have proposed the following plan
Beam Energy (GeV)
PHENIX STAR Event count
Realistic Time scales
(days)
5.0 100 K 7
6.1 1M 23
7.7 2M 20
8.6 2M 15
12.3 5M 12
17.3 10M 12
22.4
27.0 10M 7
39.0 10M 6
62.4
May a good idea to start with energies common to both experiments
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New Program : SPS - SHINEA significant difference between freeze-out and transition temperature can lead to dilution of the signatures of the QCD critical point. One way
address this is to vary system size/colliding ion size.
F. Becattini et al., PRC 73, 044905
QM09 : A. Laszlo
Experimental set up :New spectator calorimeter for centrality selectionForward Time-Of-FlightBeam pipeTPC readout
What is the difference vs. NA49 ?
Physics Program :Studying QCD Critical Point and Onset of various observations with varying colliding ion size, collision centrality and having a proper p+p baseline
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New Program : FAIR - CBMClaudia Hoehne
QM09 : C. Höhne, J. Heuser
CBM at SIS 300 will start in 2017 10-45A GeV beam energy, high availability of beam (order of
10 weeks per year), interaction rates up to 10 MHz
“CBM light” at SIS 100 in 2015 Au beam up to 11A GeV, p beam up to 30 GeV (multistrange hyperons, charm production in pA)
Assume 10 weeks beam time, 25A Gev Au+Au (minbias), no trigger, 25 kHz interaction (and storage) rate:
• “unlimited statistics” of bulk observables, e.g. ~1010-11 kaons, 1010 Λ
• low-mass di-electrons with high statistics, 106 -mesons (each)
• multistrange hyperons with high statistics, 108 , 106
High luminosity, rare probes, higher B reach
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Current StatusLattice and other QCD based models :B = 0 - Cross-overTC ~ 170-195 MeVB > 160 MeV - QCD critical point
Experiments :See distinct signatures that relevant d.o.fare quark and gluons[Tinitial(direct photons) > TC(Lattice)]No signatures of QCD critical point established, possible hints at SPS.
New distinct signatures proposed by Lattice and QCD based model calculations.Future program :Exploring the QCD phase diagramneeds to be vigorously pursued to know properties of basic constituents of matterunder extreme conditions.
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Future
With the starting of LHC (B~ 0) - we have unique opportunity to understand the properties of matter governed by quark-gluon degrees of freedom at unprecedented initial temperatures achieved in the collisions.
To make the QCD phase diagram a reality equal attention needs to be given to high baryon density region.
These two complementary programs will make our understanding clearer on
characterization of quark-gluon matter at varying baryon density finding the QCD critical point and locating the QCD phase boundary
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Thanks
Thanks to ……..J. Alam, R. Bhalerao, A. Bhasin , X. Dong, K. Grebieszkow, S. Gupta, J. M. Heuser, C. Hoehne, J. Kapusta, T. Kunihiro, L. Kumar, A. Laszlo, M. Lisa, L. Mclerran, T. K. Nayak, C. Nonaka, P. Petercky, C. Pruneau, S. Raniwala, K. Rajagopal, L. Ruan, C. Sasaki, P. Sorensen,M. Stephanov, G. Westfall, N. Xu, Z. Xu, andAll other STAR & WA98 Collaborators … for inputs/discussions/suggestions
Thanks to the Organizers.
See you at next Quark Matter …
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Multiplicity Fluctuation Results
Observable Experiment (Beam energy in GeV)
Conclusions
Multiplicity WA98(17.3)
PRC 65, 054912 (2002)
As expected from simple pp superposition models and models without phase transition
Multiplicity NA49(6 - 17.3 GeV)
PRC 78, 034914 (2008)
UrQMD approximately reproduces the scaled variances
Multiplicity PHENIX(22.5 - 200 GeV)
PRC 78, 044902 (2008)
Consistent with or below expectations from a superposition participant NN collision models
NA49WA98 PHENIX
QM09 : K. Grebieszkow
47
pT Fluctuation/Correlation Results
Observable Experiment (Beam energy in GeV) Conclusions
Mean pT NA49 (6.3 - 17.3 GeV)
arXiv : 0810.5580
Comparable to UrQMD and no energy dependence
pT
correlationsCERES (17.3 GeV)
Nucl.Phys. A 811, 179 (2008)
No non-trivial contributions beyond from HBT, coulomb interactions and jets. The correlation in range 30 < < 60 deg are zero
Mean pT and correlations
STAR (19.6 - 200 GeV)
Cu+Cu and Au+Au, PRC 72, 044902 (2005); 71, 64906 (2005)
Non-zero correlations measured, no energy dependence, HIJING under predicts. 13% excess compared to statistical reference.
<pT> and ET PHENIX (130 GeV) Non statistical fluctuations consistent with zero in <pT> and ET
NA49
PHENIXCERES STARQM09 : K. Grebieszkow
48
Old Program : Fixed Target
Hadron Mass
Bea
m E
nerg
y
6.3 GeV
7.6 GeV
12.3 GeV
Non-Uniform acceptance for different particle species
and for different beam energies in the same experimental setup
8.7 GeV
17.3 GeV
NA49 : arXiv : 0808.1237