Quark Gluon Plasma in Laboratory and in the Universe December 2, 2008, NTU, Taipei

[ I] Structure and the early Universe in the Lab. Micro-Bang and Big-Bang [II] of the Quark Universe [III] Recombination of Quarks into Hadrons Statistical Hadronization and study of QGP properties [IV] Chemical potentials in the early Universe Particle populations in the early Universe

presented by J. Rafelski, Arizona and LMU- QGP in Laboratory and in the Universe December 2 , 2008, NTU, Taipei, page 2

Relativistic heavy ion collisions at BNL-RHIC and (soon) CERN-LHC Heavy ions: atomic nuclei e.g. Au, Pb Relativistic: at RHIC E = 100mc2, and at LHC (see below): E =3, 500mc2 Experimental tools: BIG, large collaborations (on right: STAR at RHIC 1999) J. Rafelski, Arizona and LMU-Munich QGP in Laboratory and in the Universe December 2 , 2008, NTU, Taipei, page 3 ROOTS OF RELATIVISTIC HEAVY ION COLLISION PROGRAM STRUCTURED VACUUM – ORIGIN OF MASS: Melt the vacuum structure and demonstrate mobility of quarks – ‘deconfinement’ – vacuum state determines what fundamental laws prevail in nature. The confining vacuum state is the origin of 99.9% of the rest mass present in the Universe. The celebrated Higgs mechanism covers the remaining 0.1% .

RECREATE THE EARLY UNIVERSE IN LABORATORY: Recreate and understand the high energy density conditions pre- vailing in the Universe when matter formed from elementary de- grees of freedom (quarks, gluons) at about 10-40 µs after . Hadronization of the Universe led to nearly matter-antimatter sym- 10 metric state, the sequel annihilation left the small 10− matter asymmetry, the world around us. J. Rafelski, Arizona and LMU-Munich QGP in Laboratory and in the Universe December 2 , 2008, NTU, Taipei, page 4

Stages in the evolution of the Universe

Visible Matter Density [g cm −3 ] 15 3 −9 10 10 10 10 27 LHC 16 quarks 10 1 TeV combine RHIC atoms antimatter form disappears photons 13 neutrinos 10 decouple decouple 1 GeV SPS nuclear reactions: light nuclei formed era of 10 galaxies 10 and stars 1 MeV Particle energy Particle 7 Temperature [K] OBSERVATIONAL 10 COSMOLOGY 1 keV

4 10 PARTICLE/NUCLEAR ASTROPHYSICS 1 eV

10 10 10 −12 −6 6 12 18 10 10 1 10 day year ky My today Time [s] J. Rafelski, Arizona and LMU-Munich QGP in Laboratory and in the Universe December 2 , 2008, NTU, Taipei, page 5

What is deconfinement? A domain of (space, time) much larger than normal hadron size in which color-charged quarks and gluons are propagating, con- strained by external ‘frozen vacuum’ which abhors color.

We expect a pronounced boundary in temperature and density be- tween confined and deconfined phases of matter: phase diagram. Deconfinement expected at both: high temperature and at high matter density. In a finite size system not a singular boundary, a ‘transformation’. THEORY: What knowledge we need Hot QCD in equilibrium (QGP from QCD-lattice) and out of chemical equilibrium

DECONFINEMENT NOT A ‘NEW PARTICLE’, there is no good answer to journalists question: How many new vacuua have you produced today? J. Rafelski, Arizona and LMU-Munich QGP in Laboratory and in the Universe December 2 , 2008, NTU, Taipei, page 6 Vacuum structure Quantum vacuum is polarizable: see atomic vac. pol. level shifts Quantum structure of gluon-quark fluctuations: glue and quark condensate evidence from LGT, ’onium sum rules Permanent fluctuations/structure in ‘space devoid of matter’: even though V Ga V = 0, with G2 Ga Gµν =2 [B~ 2 E~ 2] , h | µν| i ≡ µν a a − a Xa Xa αs 2 2 4 4 we have V G V (2.3 0.3)10− GeV = [390(12)MeV] , h | π | i ≃ ± and V uu¯ + dd¯ V = 2[225(9) MeV]3 . h | | i −

Vacuum and Laws of Physics Vacuum structure controls early Universe properties Vacuum determines inertial mass of ‘elementary’ particles by the way of the Higgs mechanism, m = g V h V , i ih | | i Vacuum is thought to generate color charge confinement: hadron mass originates in QCD vacuum structure. Vacuum determines interactions, symmetry breaking, etc..... DO WE REALLY UNDERSTAND HOW THE VACUUM CON- TROLS INERTIA (RESISTANCE TO CHANGE IN VELOCITY)?? J. Rafelski, Arizona and LMU-Munich QGP in Laboratory and in the Universe December 2 , 2008, NTU, Taipei, page 7

RECREATING THE EARLY UNIVERSE IN LABORATORY

Micro-Bang

Pb Pb AuQGP Au

Big-Bang Micro-Bang

τ −∼ 10 µ s τ −∼ 4 10-23 s ∼ -10 ∼ NBB / N − 10 N / N − 0.1

Orders of Magnitude STAR at RHIC ENERGY density ǫ 1–50GeV/fm3 = 0.18–91016g/cc ≃ Latent vacuum heat B 0.1–0.4GeV/fm3 (166–234MeV)4 ≃ 1 ≃30 PRESSURE P = 3ǫ = (0.52 26)10 barn − 12 TEMPERATURE T0,Tf 700–250, 175–145 MeV; 300MeV 3.5 10 K ≃ J. Rafelski, Arizona and LMU-Munich QGP in Laboratory and in the Universe December 2 , 2008, NTU, Taipei, page 8

Where is T, µb phase boundary System very fine-tuned. Is there a Phase transition, what if? La- tent heat? Will lattice yield answers, are heavy ion experiments ABLE to provide the answer? Another fine-tuning: the “true” vac- uum state has about 100 orders of magnitude lower energy density than the deconfined phase. • Lattice explores equilibrium conditions, temperature of phase transition depends on available degrees of freedom. For 2+1 flavors: T = 162 3 10 For 2 flavors T 170 MeV,± the± nature of phase transition/transformation changes when→ number of flavors rises from 2 to 2+1 to 3 • Nuclear collision explore non-equilibrium, there are two distinct dynamical effects – Matter expansion, flow effect: colored partons like a wind, displace the boundary

– Active degrees of freedom are 2+ γs J. Rafelski, Arizona and LMU-Munich QGP in Laboratory and in the Universe December 2 , 2008, NTU, Taipei, page 9 Challenge: Discover / Diagnosis and Study of 23 QGP properties at 10− s scale • Deep probes (diletpons and photons) • J/Ψ • Dynamics of quark matter flow • Jet tomography • Strangeness • Strange Antibaryons J. Rafelski, Arizona and LMU-Munich QGP in Laboratory and in the Universe December 2 , 2008, NTU, Taipei, page 10 Strangeness: a popular laboratory QGP diagnostic tool • There are many strange particles allowing to study different physics questions (q = u, d): φ(ss¯), K(qs¯), K(¯qs), Λ(qqs), Λ(¯qq¯s¯), Ξ(qss), Ξ(¯qs¯s¯), Ω(sss), Ω(¯ss¯s¯) . . . resonances . . . • Several strange hadrons subject to a self analyzing decay within a few cm from the point of production π π

Ξ Λ p

• Production rates hence statistical significance is high J. Rafelski, Arizona and LMU-Munich QGP in Laboratory and in the Universe December 2 , 2008, NTU, Taipei, page 11 • production of strangeness in thermal processes in plasma

g s s g s dominant processes: g GG T ss¯ h i → g s g strangeness g s s abundance due to ‘free’ gluons =evidence for plasma q s

10–15% of total rate: qq¯ T ss¯ h i → q s • coincidence of scales: ms Tc τs τ ≃ → ≃ QGP → clock for QGP phase strangeness chemical equilibration in QGP possible

• s¯ q¯ strange antibaryon enhancement at≃ RHIC→ (anti)hyperon dominance of (anti)baryons. J. Rafelski, Arizona and LMU-Munich QGP in Laboratory and in the Universe December 2 , 2008, NTU, Taipei, page 12

QCD Thermal strangeness production/equilibration Kinetic (momentum) equilibration is faster than chemical, use thermal particle distributions f(~p1, T ) to obtain average rate: 3 3 d p1 d p2σ12v12f(~p1, T )f(~p2, T ) σvrel T 3 3 . h i ≡ R d Rp1 d p2f(~p1, T )f(~p2, T ) R R The generic angle averaged cross sections for (heavy) flavor s, s¯ production pro- cesses g + g s +¯s and q +q ¯ s +¯s , are: → → 2 2 4 2 2παs 4ms ms 1 7 31ms σ¯gg ss¯(s) = 1 + + tanh− W (s) + W (s) , → 3s  s s2  − 8 8s   2 2 8παs 2ms 2 σ¯qq¯ ss¯(s) = 1 + W (s) .W (s) = 1 4ms /s → 27s  s  − PARTIAL RESUMMATIONp The relatively small experimental value α (M ) 0.118, established in recent years s Z ≃ QCD resummation with running αs and ms taken at the energy scale µ √s . Effective T -dependence: ≡ α (T ) α (µ =2πT ) α (T ) s c s ≡ s ≃ 1+(0.760 0.002) ln(T/T ) ± c with αs(Tc)=0.50 0.04 and Tc =0.16 GeV. 2 ± NOTE: αs varies by factor 10 J. Rafelski, Arizona and LMU-Munich QGP in Laboratory and in the Universe December 2 , 2008, NTU, Taipei, page 13

Strangeness relaxation to chemical equilibrium in QGP Strangeness density time evolution in local rest frame:

dρs dρs¯ 1 2 gg ss¯ qq¯ ss¯ ss¯ gg,qq¯ = = ρ (t) σv → + ρ (t)ρ (t) σv → ρ (t) ρ (t) σv → dτ dτ 2 g h iT q q¯ h iT − s ¯s h iT

Evolution for s and s¯ identical, which allows to set ρs(t) = ρs¯(t). Note invariant production rate A and the characteristic time constant τs:

12 34 1 12 34 ρs( ) A → γ1γ2ρ1∞ρ2∞ σsv12 T → . 2τs gg ss¯ ∞qq¯ ss¯ ≡ 1+δ1,2 h i ≡ A → +A → +... J. Rafelski, Arizona and LMU-Munich QGP in Laboratory and in the Universe December 2 , 2008, NTU, Taipei, page 14 NEW HADRON FORMATION MECHANISM FROM QGP

1. GG ss¯ (thermal gluons collide) → Ω GG cc¯ (initial parton collision) → ¯ u s s s GG bb (initial parton collision) u u → g s gluon dominated reactions u d d d s s s s d g d 2. RECOMBINATION of pre-formed g s g u g u ¯ u s g s, s,¯ c, c,¯ b, b quarks s s d u u d g s d Formation of complex rarely produced d d multi flavor (exotic) (anti)particles s g g u s s from QGP enabled by coalescence u d d g u between s, s,¯ c, c,¯ b, ¯b quarks made in different microscopic reactions; s s u this is signature of quark mobility Ξ and independent action, thus of deconfinement. Moreover, strangeness enhancement = gluon mobility. Enhancement of flavored (strange, charm,. . . ) antibaryons pro- gressing with ‘exotic’ flavor content. J. Rafelski, Arizona and LMU-Munich QGP in Laboratory and in the Universe December 2 , 2008, NTU, Taipei, page 15

A new dominant mechanism of particle formation clearly visible

2.5 Λ Baryon to Meson Ratio 0 AuAu200 (STAR) AuAu130 (STAR) KS p Ratios Λ/KS and p/π in Au-Au com- 2 - AuAu200 (PHENIX) pp200 (STAR) π pared to pp collisions as a function of 1.5 p . The large ratio at the intermediate ⊥ p region: evidence that particle for- 1 ⊥

Baryon/Meson mation (at RHIC) is distinctly different from fragmentation processes for the el- 0.5 + ementary e e− and pp collisions.

0 0 2 4

pT [GeV/c] In statistical hadronization: nonequilibrium parameters needed

• γq (γs,γc,...): u,d (s, c, . . .) quark phase space yield, absolute chemical equilib- n rium: γi 1 γ3 → baryons q γs 2 mesons ∝ γq · γq 

• γs/γq shifts the yield of strange vs non-strange hadrons: Λ(¯ud¯s¯) γ K+(us¯) γ φ γ2 Ω(sss) γ2 s , s , s , s , ¯ + ¯ 2 2 p¯(¯uu¯d) ∝ γq π (ud) ∝ γq h ∝ γq Λ(sud) ∝ γq J. Rafelski, Arizona and LMU-Munich QGP in Laboratory and in the Universe December 2 , 2008, NTU, Taipei, page 16

MATTER-ANTIMATTER SYMMETRY (COMPARE TO EARLY UNIVERSE) Recombination hadronization implies symmetry of m spectra of ⊥ (strange) baryons and antibaryons also in baryon rich environment.

THIS IMPLIES: A common matter-antimatter particle formation mechanism, AND negligible antibaryon re-annihilation/re-equilibration/rescattering.

Such a nearly free-streaming particle emission by a quark source into vacuum also required by other observables: e.g. reconstructed yield of hadron resonances and HBT particle correlation analysis

v Practically no hadronic ‘phase’ f No ‘mixed phase’ Direct emission of free-streaming hadrons from exploding filamentary QGP QGP

Develop analysis tools viable in SUDDEN QGP HADRONIZATION

Possible reaction mechanism: filamentary/fingering instability when in expan- sion the pressure reverses. J. Rafelski, Arizona and LMU-Munich QGP in Laboratory and in the Universe December 2 , 2008, NTU, Taipei, page 17

WA97 T Pb [MeV] 0 ⊥ 2 T K 230 2 10 WA97 Pb-Pb ± ] 158 A GeV T Λ 289 3 -2 ± 10 T Λ 287 4 Ξ ± 1 T 286 9 [GeV × Λ ± T -1 10 T Ξ 284 17 10  ± ×10 Λ T Ω+Ω 251 19 -2 Ξ ± 10  + dN/dm Ξ

T -3 10

1/m -4 × 10-1 Ω- 10  -5 ×10-2 Ω+ Λ within 1% of Λ 10 Kaon – hyperon difference: 1 2 3 4 EXPLOSIVE FLOW effect mT [GeV] Difference between Ω+ Ω: presence of an excess of low p particles ⊥ we will return to study this in spectral analysis J. Rafelski, Arizona and LMU-Munich QGP in Laboratory and in the Universe December 2 , 2008, NTU, Taipei, page 18

Ξ−, Ξ− Spectra RHIC-STAR 130+130 A GeV 1 -2 )

2 - + + 10 -1 (a) Ξ (b) Ξ

10 -2 dy (GeV/c ⊥ 10 -3 N/dm 2

d -4 ⊥ 10 m π -5

1/(2 10

evt [0-10%] [10-25%] (/5) [25-75%] (/10) -6 1/N 10 0 1 2 0 1 2 2 m ⊥ - m (GeV/c ) J. Rafelski, Arizona and LMU-Munich QGP in Laboratory and in the Universe December 2 , 2008, NTU, Taipei, page 19 Where is phase boundary as function of energy? Competition between speed of strangeness production and baryon density (i.e. transparency). 〉 + π〈 / 〉

+ Rise of s¯ Rise of d¯

K decrease of baryon density 〈 0.2

0.1

A+A: NA49 AGS p+p RHIC

0 2 1 10 10

The NA49 HORN sNN (GeV) J. Rafelski, Arizona and LMU-Munich QGP in Laboratory and in the Universe December 2 , 2008, NTU, Taipei, page 20

Discovery of early thermalization: Azimuthal asymmetry

K++K- 0 STAR

2 K 0.1 S v Λ+Λ Quark v 2 = v 2/n(p T/n) Ξ+Ξ

0.05 Quark Anisotropy Quark Anisotropy

0 0 1 2 3

Quark Transverse Mom. pT [GeV/c] Evidence for common bulk q, q,s,¯ s¯-partonic matter flow. The ab- sence of gluons at hadronization is consistent with the absence of charge fluctuations, Quark scaling seen at STAR: A superb confir- mation that dynamics of the fireball is in thermal partonic degrees of freedom, and quarks hadronize. J. Rafelski, Arizona and LMU-Munich QGP in Laboratory and in the Universe December 2 , 2008, NTU, Taipei, page 21

Hadronization of the Quark Universe Just about the same as in laboratory (first impression)

Upon QGP hadronization there is initially nearly as much matter as antimatter . In an initially nearly homogeneous Universe this symmetry remains during the ensuing annihilation period till an- nihilation consumed all but the tiny initial state asymmetry that remains today. This remnant is an INPUT into any analysis, de- rives from Baryon/Photon ratio (= baryon/entropy). • When do antinucleons, strangeness, pions disappear in homoge- neous Universe? • What happens to the Universe during matter-antimatter anni- hilation? • When is pion density equal to baryon density? J. Rafelski, Arizona and LMU-Munich QGP in Laboratory and in the Universe December 2 , 2008, NTU, Taipei, page 22

Baryon to photon ratio in the Universe

G. Steigman, astro-ph/0511534 G. A. Steigman, astro−ph/0202187 (2002) Int.J.Mod.Phys. E15 (2006) 1-36 1

Deuterium Abundance and Big Bang Nucleosynthesis Modeling 0.8

Baryon density perturbations and anisotropy 0.6 in the Cosmic Microwave Background at photon freeze−out Likelihood

0.4

0.2 SNIa magnitude−redshift combined with the Sunyaev−Zeldovich effect

0 0 5 10 15 η10 γ 10 = 10 B/ 10 Deuteron abundance, W-MAP: η =6.1 0.15 10− ; 10 ± × This yields entropy per baryon: S S N 8.0 = γ = =1.3 0.11010 B B¯ Nn B B¯ η ± − γ − + (Sγ + Sν + Si)/nγ is evaluated using stat.mech. and remembering e e− reheating of photons. J. Rafelski, Arizona and LMU-Munich QGP in Laboratory and in the Universe December 2 , 2008, NTU, Taipei, page 23

Hadronization of the Quark Universe

• We need to establish chemical conditions in the early Universe (chemical potentials, equilibria); • We need to resolve conflict of Gibbs hadronization conditions with super- selection rules such as local charge conservation/neutrality, require mixed phase, separation of phases To obtain the evolution of hadron yields: Quantitative Tasks 1)Time scale of Universe hadronization determines which interactions are active.

2) Identify the chemical conservation laws constraining potentials µi(T ) and the pertinent conservation laws; 3) Trace out chemical potentials as function of T , (which we can study separately as function of time); 4) Evaluate the composition of the Universe during evolution toward the condi- tion of neutrino decoupling at T 1 MeV t 10 s ≃ ≃ 5) Explore the quark-hadron phase transformation dynamics, and distillation of conserved quantum numbers: baryon, electrical charge (not in this talk, time constraint). J. Rafelski, Arizona and LMU-Munich QGP in Laboratory and in the Universe December 2 , 2008, NTU, Taipei, page 24 Compare time scales in QGP hadronization STRONG INTERACTIONS TIME CONSTANT: 23 Nucleon size / light velocity 10− s ≃ The expanding Universe cools, the hot quark-gluon plasma freezes into individual hadrons. In laboratory we do this suddenly, in the early Universe slowly as seen on time scale of strong interactions.

UNIVERSE HADRONIZATION TIME CONSTANT: 2 3c 0 GeV τU = = 36 µs B , 0 0.19 r32πG r B ≃ fm3 B B Here, 4 is energy density inside particles like protons, and is the B amount of energy required per unit of volume to deconfined quarks.

IN THE EARLY UNIVERSE aside of strong also EM and WEAK reactions relax towards equilibrium. Many additional (compared to heavy ion reactions) active degrees of freedom. J. Rafelski, Arizona and LMU-Munich QGP in Laboratory and in the Universe December 2 , 2008, NTU, Taipei, page 25 CHEMICAL POTENTIALS IN THE UNIVERSE The slow hadronization of the Universe implies hadronic chemical equilibrium and full participation of electromagnetically interacting photon and lepton degrees of freedom. • Photons in chemical equilibrium, Planck distribution, zero pho- ton chemical potential; i.e.: µγ =0 • reactions such as f + f¯ ⇋ 2γ are in equilibrium, (here f and f¯ are a fermion – anti-fermion pair), hence: µ = µ ¯ f − f • Minimization of the Gibbs free energy implies that chemical equilibrium arises for the condition: νiµi =0 for any reaction νiAi = 0, where νi are the reaction equation coefficients of the chemical species Ai;

• Example: weak interaction reactions lead to: µs = µd = µu +∆µl µ µ = µ µ = µ µ ∆µ e − νe µ − νµ τ − ντ ≡ l • For the “large mixing angle” solution the neutrino oscillations ν ⇋ ν ⇋ ν imply that: µ = µ = µ µ e µ τ νe νµ ντ ≡ ν neutrino mixing may be accelerated in ‘dense’ matter. J. Rafelski, Arizona and LMU-Munich QGP in Laboratory and in the Universe December 2 , 2008, NTU, Taipei, page 26

Physical observables and chemical conditions The three chemical potentials not constrained by chemical reactions are obtained from three physical constraints: i. Local electrical charge neutrality (Q =0): n Q n (µ ,T )=0, Q ≡ i i i Xi

where Qi and ni are the charge and number density of species i.

ii. Net lepton number equals net baryon number (L = B): n n (L B ) n (µ ,T )=0, L − B ≡ i − i i i Xi (standard condition in baryo-genesis models, generalization to finite B L easily possible) − iii. Universe evolves adiabatically i.e. at constant in time entropy-per-baryon S/B σ σ (µ ,T ) i i i = 1.3 0.1 1010 nB ≡ Pi Bi ni(µi,T ) ± × P J. Rafelski, Arizona and LMU-Munich QGP in Laboratory and in the Universe December 2 , 2008, NTU, Taipei, page 27

THE (EARLY) UNIVERSE: PROCEDURE: There are three chemical potentials which are ‘free’ and we choose to follow: µd, µe, and µν. (we need physical observables to fix these values)

Quark chemical potentials are convenient to characterize the particle abundances in the hadron phase, e.g. Σ0 (uds) has chem- ical potential µΣ0 = µu + µd + µs

The baryochemical potential is: µ + µ µ + µ 3 3 µ P N =3 d u =3µ ∆µ = 3µ (µ µ ). b ≡ 2 2 d − 2 l d − 2 e − ν J. Rafelski, Arizona and LMU-Munich QGP in Laboratory and in the Universe December 2 , 2008, NTU, Taipei, page 28

TRACING µd IN THE UNIVERSE T (MeV) 700 170 100 10 2 10 10 -6 313.6 MeV 0 10 10 -7 µ -2 -8 d 10 10 10 20 30 40 50 µ e µ ν

(MeV) -4

µ 10 mixed phase HG / QGP 1 eV 10 -6 Minimum µ =1.1 0.1 0.16 eV b ± ± 10 -8 10 0 10 1 10 2 10 3 10 4 t ( µ s) J. Rafelski, Arizona and LMU-Munich QGP in Laboratory and in the Universe December 2 , 2008, NTU, Taipei, page 29

TRACING µd IN A UNIVERSE: different presentation

11 150 S/B = 4.5 x 10 10 S/B = 4.5 x 10 9 S/B = 4.5 x 10 125 8 S/B = 4.5 x 10 7 S/B = 4.5 x 10 6 100 S/B = 4.5 x 10 5 S/B = 4.5 x 10

75 T (MeV)

50

25

Fromerth & Rafelski, January 2003 0 -6 -4 -2 0 2 10 10 10 10 10 µ (MeV) d J. Rafelski, Arizona and LMU-Munich QGP in Laboratory and in the Universe December 2 , 2008, NTU, Taipei, page 30

Hadronic Particle Densities 10 40 nuclear dens. protons neutrons 35 π 0 10 − ) π 3 π + lambdas 30 antiprotons 10 antineutrons antilambdas 10 25 atomic dens. density (particles / cm (particles density 10 20

15 10 1 10 100 T (MeV) Note the baryon freeze-out at T 37 MeV and that pion density ≃ remains at baryon density down to T 4.5 MeV ≃ J. Rafelski, Arizona and LMU-Munich QGP in Laboratory and in the Universe December 2 , 2008, NTU, Taipei, page 31

Lepton Densities 10 40 nuclear dens. electrons muons 35 taus 10 positrons )

3 antimuons antitaus neutrinos (total) 10 30 antineutrinos (total)

10 25 atomic dens. density (particles / cm (particles density 10 20

15 10 1 10 100 T (MeV) J. Rafelski, Arizona and LMU-Munich QGP in Laboratory and in the Universe December 2 , 2008, NTU, Taipei, page 32

Distillation Process–Separation of Phases Strangeness distillation mechanism proposed for QGP hadroniza- tion. In HI collisions no time to distill, applicable in early Universe to electrical charge, baryon number etc. distillation. Mixed phase partition function for the SLOW phase transformation period:

VHG VQGP ln Ztot = ln ZHG + ln ZQGP Vtot = VHG + VQGP Vtot Vtot At QGP hadronization there is in general unequal conserved quan- tum number density in QGP and in hadron gas (HG) phases.

The constraints are accordingly, e.g. for electrical charge:

QGP HG QGP HG Q =0= nQ VQGP + nQ VHG = Vtot (1 fHG) nQ + fHG nQ h − i f V /V is the fraction of space belonging to HG phase. HG ≡ HG tot Note: Mixed phase lasts 10 µs (25% of prior lifespan), we had as- ≃ sumed that fHG changes linearly in time. Actual values will require dynamic nucleation and transport theory description of the phase transformation. J. Rafelski, Arizona and LMU-Munich QGP in Laboratory and in the Universe December 2 , 2008, NTU, Taipei, page 33

Charge (and baryon number) asymmetry distillation

Initially at fHG =0 all matter in QGP phase, as hadronization progresses with fHG 1 the baryon component in hadronic→ gas reaches 100%.

The constraint to a charge neutral universe conserves the SUM of charges in both fractions. Charge in each fraction can be and is non-zero. 0.1

0.05 B

/ n 0 Q

n Even a small charge separation be- tween phases introduces a finite -0.05 non-zero local Coulomb potential HG QGP and this amplifies any existent -0.1 baryon asymmetry (protons vs 0 0.5 1 antiprotons). f HG J. Rafelski, Arizona and LMU-Munich QGP in Laboratory and in the Universe December 2 , 2008, NTU, Taipei, page 34 SUMMARY–EARLY UNIVERSE There is a lot left to do. Nonequilibrium effects for 1 < T < 45 MeV: kinetic reaction method to describe evolution, statistical densities no reliable.

Separation of phases leads to inhomogeneous Universe, how is this erased, and or not, signatures?

Influence and participation of dark matter. J. Rafelski, Arizona and LMU-Munich QGP in Laboratory and in the Universe December 2 , 2008, NTU, Taipei, page 35

QGP Study Summary

• Strangeness experimental results fulfill all our expectations: clear production anomalies following pattern predicted for QGP • Analysis of strangeness and hadron energy excitation functions and centrality dependence is now available. Behavior agrees with kinetic models of QCD thermal strangeness production

• QCD based kinetic evaluation of the two QGP global observables γs and s/S agrees with experiment. CHEMICAL equilibration of the QGP at RHIC; • QCD kinetic model tuned to describe strangeness at RHIC, predicts further increase of specific enhancement at LHC. • Strangeness equilibration can impact phase boundary and transition proper- ties since QCD matter with 2+1 flavors exceptionally fine tuned.