THE FUTURE OF RELATIVISTIC HEAVY ION COLLISIONS Workshop on “Future of Nuclear Collisions at High Energy”, Kielce, October 14-17, 2004

This is not a workshop summary. I describe major accomplishments (some not yet mentioned) and offer implied and/or explicit challenges. +50% of content is for STUDENTS who ARE actually THE FUTURE of relativistic heavy ion nuclear collisions. [ I] Why and How: deconfinement [ II] Where and what we do p6 [III] Flavor QGP Signatures p11 [IV] production Resonances p16 [V] Onset of deconfinement QGP p24 [VI] Flavor at LHC p28

Supported by a grant from the U.S. Department of Energy, DE-FG02-04ER41318

Johann Rafelski Department of Physics University of Arizona TUCSON, AZ, USA

1 J. Rafelski, Arizona The future of RHI Collisions Kielce, October 17, 2004, page 2

The origin of this research program to move on with other issues in fundamental understanding of the world around us, we need to make this ‘next step’ STRUCTURED VACUUM: Melt the vacuum structure and demonstrate mobility of – ‘deconfinement’. This demonstrates that the vacuum is a key component in the understanding of what we observe in terms of the fundamental laws of nature. This leads to understanding of the origin of 99% of the rest mass present in the Universe – The Higgs mechanism covers the remaining 1% (or less). EARLY UNIVERSE: Recreate and understand the high energy density conditions pre- vailing in the Universe when formed from elementary de- grees of freedom (quarks, ) at about 10-40µs after big bang. Hadronization of the Universe led to nearly -antimatter sym- metric state, the sequel annihilation left the small 10−10 matter asymmetry, the world around us. J. Rafelski, Arizona The future of RHI Collisions Kielce, October 17, 2004, page 3

What is deconfinement? A domain of (space, time) much larger than normal 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 FUTURE What we need as background knowledge: 1) Hot QCD in/out of equilibrium (QGP from QCD-lattice) 2) Understanding from first principles and not as descriptive method of hadronization dynamics and final hadron yields, 3) More sensitive (hadronic and other) signatures of deconfinement beware: final always , many decay into DECONFINEMENT NOT A ‘NEW PARTICLE’, there is no answer to journalists question: How many new vacuua have you produced today? J. Rafelski, Arizona The future of RHI Collisions Kielce, October 17, 2004, page 4 Vacuum structure Quantum vacuum is polarizable: see atomic vac. pol. level shifts Quantum structure of - fluctuations: glue and quark condensate evidence from LGT, ’onium sum rules Permanent fluctuations/structure in ‘space devoid of matter’: a 2 a µν ~ 2 ~ 2 even though hV |Gµν|V i = 0, with G ≡ GµνGa = 2 [Ba − Ea ] , a a α X X we have hV | sG2|V i ' (2.3 § 0.3)10−2GeV4 = [390(12) MeV]4 , π and hV |uu¯ + dd¯ |V i = −2[225(9) MeV]3 .

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,

mi = gihV |h|V 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 The future of RHI Collisions Kielce, October 17, 2004, page 5

Do we really understand how annihilation of almost all matter-antimatter occurs?

Visible Matter Density [g cm −3 ] 15 3 −9 10 10 10 10 27 LHC 16 quarks 10 1 TeV combine RHIC antimatter form disappears 13 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 1 keV COSMOLOGY

4 10 PARTICLE/NUCLEAR ASTROPHYSICS 1 eV

10 10 10 −12 −6 6 12 18 10 10 1 Time [s] 10 day year ky My today J. Rafelski, Arizona The future of RHI Collisions Kielce, October 17, 2004, page 6 EXPERIMENTAL HEAVY ION PROGRAM

— LHC

AT CERN: LHC opens after 2007 and SPS resumes after 2009 J. Rafelski, Arizona The future of RHI Collisions Kielce, October 17, 2004, page 7 ...and at BROOKHAVEN NATIONAL LABORATORY

Relativistic Heavy Ion Collider: RHIC J. Rafelski, Arizona The future of RHI Collisions Kielce, October 17, 2004, page 8 BROOKHAVEN NATIONAL LABORATORY

12:00 o’clock PHOBOS BRAHMS 10:00 o’clock 2:00 o’clock

RHIC PHENIX 8:00 o’clock STAR 4:00 o’clock 6:00 o’clock Design Parameters: BeamEnergy = 100 GeV/u U-line 9 GeV/u No. Bunches = 57 High Int. Source BAF (NASA) µg-2 9 Q= +79 No. Ions /Bunch = 1×10 LI NAC T = 10 hours BOOSTER store L = 2×1026 cm-2sec-1 Pol. Proton Source ave AGS HEP/NP

1 MeV/u Q= +32 TANDEMS

Relativistic Heavy Ion Collider: RHIC J. Rafelski, Arizona The future of RHI Collisions Kielce, October 17, 2004, page 9

CERN SPS: THE FIRST LOOK AT DECONFINED UNIVERSE IN THE LABORATORY

Micro-Bang 135

81

Pb QGP Pb Au Au 115 47

363

353 Big-Bang Micro-Bang

τ −∼ 10 µ s τ −∼ 4 10-23 s ∼ -10 ∼ NB / N − 10 NB / N − 0.1 Order of Magnitude ENERGY density ² ' 1–5GeV/fm3 = 1.8–9 1015g/cc

Latent vacuum heat B ' 0.1–0.4GeV/fm3 ' (166–234MeV)4

1 30 PRESSURE P = 3² = 0.52 10 barn Peter Seyboth, NA35 1986: S–Ag at 200AGeV

12 TEMPERATURE T0, Tf 300–250, 175–145 MeV; 300MeV'3.5 10 K J. Rafelski, Arizona The future of RHI Collisions Kielce, October 17, 2004, page 10

THE EARLY UNIVERSE AT RHIC

STAR . . . and BRAHMS, PHOBOS: How is this maze of tracks of newly produced particles telling us what we want to know about the early Universe and its properties? Study of patterns in particle production: correlations, new flavors (strangeness, charm), resonances, etc.. J. Rafelski, Arizona The future of RHI Collisions Kielce, October 17, 2004, page 11

Tasks for hadronic/flavor QGP signatures 1. New directions: LHC Flavor signatures = Signatures of flavor

* Mixed charm-bottom states Bc(bc¯) etc. will be made extremely abundantly (comparing to pp) in the quark soup at LHC, this opens up precision laboratory of atomic QCD * Charm and bottom yield at LHC: in depth tests of small-x structure functions 2. Search for onset of deconfinement as function of energy and of system size Marek Ga´zdzicki with NA49 3. Resonances, statistical hadronization, bulk matter dynamics, critical (phase boundary) chemical nonequilibrium Furthermore: recall 1) J/Ψ suppression turns into enhancement as soon as ‘enough’ charm pairs per reaction available. 2) Hard parton jets: is it absorption of decay products, or energy stopping or both; relation to QGP physics? 3) Dileptons and photons are predominantly produced in final state decays J. Rafelski, Arizona The future of RHI Collisions Kielce, October 17, 2004, page 12 TWO STEP HADRON FORMATION MECHANISM IN QGP Ω 1. GG → ss¯ GG → cc¯ u s s s u u g s reaction gluon dominated u d d d s s s s 2. hadronization of pre-formed d g d g s g u g u s, s,¯ c, c¯ quarks u s g s s d u u Formation of complex rarely d g s d d produced (multi)exotic flavor d s g g u (anti)particles from QGP enabled s s u d by coalescence between s, s,¯ c, c¯ d g u quarks made in different microscopic s s u reactions; this is signature of quark Ξ mobility and independent action, thus of deconfinement. Enhance- ment of flavored (strange, charm) antibaryons progressing with ‘exotic’ flavor content. AVAILABLE RESULT (SPS, RHIC): Enhancement of strange (anti) progresses with strangeness content. J. Rafelski, Arizona The future of RHI Collisions Kielce, October 17, 2004, page 13

(MULTI)STRANGE (ANTI) ENHANCEMENT

WA97: central 158 A GeV Pb - Pb 10 Enhancement Enhancement

1 - 0 ± ± ± h KS Λ Ξ Λ Ξ Ω+Ω

0 1 2 1 2 3 Strangeness Enhancement GROWTH with strangeness antiquark content. Enhancement is here defined with respect to the yield in p–Be col- lisions, scaled up with the number of collision ‘wounded’ nucleons.

0 1 2 3 4 5 6 J. Rafelski, Arizona The future of RHI Collisions Kielce, October 17, 2004, page 14 ENHANCEMENT AS FUNCTION OF REACTION VOLUME

> < > < pT 0, |y-ycm| 0.5 NA57 158 A GeV pT 0, |y-ycm| 0.5 NA57 158 A GeV  Ω-+Ω+

10 10 Ξ-

 Ξ+ Λ

 Λ Particle / event / wound. nucl. relative to pBe Particle / event / wound. nucl. Particle / event / wound. nucl. relative to pBe nucl. relative / event / wound. Particle 1 1

pBe pPb PbPb pBe pPb PbPb

2 3 2 3 1 10 10 10 1 10 10 10 < > < > Nwound Nwound Note the gradual onset of enhancement with reaction volume. “Canonical enhancement” (a hadronic equilibrium model) is grossly inconsistent with these results. Gradual enhancement shown pre- dicted by kinetic strangeness production. J. Rafelski, Arizona The future of RHI Collisions Kielce, October 17, 2004, page 15

ENHANCEMENT at low SPS Energy

> < > < pT 0, |y-ycm| 0.5 NA57 40A GeV pT 0, |y-ycm| 0.5 NA57 40A GeV

Ξ- 10 10

 Ξ+ Λ

 Λ Particle / event / wound. nucl. relative to pBe Particle / event / wound. nucl. Particle / event / wound. nucl. relative to pBe nucl. relative / event / wound. Particle 1 1

pBe PbPb pBe PbPb

1 10 102 103 1 10 102 103 < > < > Nwound Nwound At 40A GeV we still see a strong volume dependent hyperon en- hancement, in agreement with expectations for deconfined state formation. J. Rafelski, Arizona The future of RHI Collisions Kielce, October 17, 2004, page 16

REACTION MECHANISM OF PARTICLE PRODUCTION

several CERN experiments since 1991 demonstrate symmetry of m⊥ spectra of strange baryons and antibaryons in rich environment, now also observed at RHIC. Interpretation: Common matter-antimatter particle formation mechanism, little reannihilation in sequel evolution. Appears to be emission by a quark source into vacuum. Fast hadronization confirmed by HBT particle correlation analysis: same size source at all energies

Practically no hadronic ‘phase’! vf No ‘mixed phase’ either! Direct emission of free-streaming hadrons from exploding filamenitating QGP QGP Develop analysis tools viable in SUDDEN QGP HADRONIZATION

Proposed reaction mechanism: filamentation/fingering instability when in ex- pansion pressure reverses. A big player is filamentation is Stanislaw Mr´owczynski, chair of this meeting J. Rafelski, Arizona The future of RHI Collisions Kielce, October 17, 2004, page 17 STATISTICAL HADRONIZATION: Resonances Fermi (micro canonical)-Hagedorn (grand canonical) particle ‘evap- oration’ from hot fireball:particles produced into accessible phase space, yields and spectra thus predictable. 1.0 T=140 MeV 0.9 HOW TO TEST SH: T=160 MeV T=180 MeV Study of particle yields with 0.8 π Λ same quark content, e.g. the 0.7 p relative yield of ∆(1230)/N , 0.6 K K∗/K, Σ∗(1385)/Λ, etc, which is 0.5 Ξ controlled by chemical freeze- 0.4 out temperature T : 0.3 * Resonance contribution Resonance K ∗ ∗ ∗ 3/2 −m∗/T 0.2 N g (m T ) e φ Ω~0 = 0.1 N g(mT )3/2e−m/T 0.0 0.0 0.5 1.0 1.5 Mass Resonances decay rapidly into ‘stable’ hadrons and dominate the yield of most stable hadronic particles. Resonances test both statistical hadronization principle and per- haps more importantly, due to their short and diverse lifespan characterize the dynamics of QGP hadronization. J. Rafelski, Arizona The future of RHI Collisions Kielce, October 17, 2004, page 18 OBSERVABLE RESONANCE YIELDS Invariant mass method: construct invariant mass from decay prod- ucts: 2 2 2 2 2 2 2 M = ( ma + p~a + mb + p~b + . . .) − (p~a + p~b + . . .) If one of decay prop ducts rescatterq the reconstruction not assured.

Strongly interacting matter essentially non-transparent. Simplest model: If resonance decays N ∗ → D + . . . within matter, resonance can disappear from view. Model implementation: dN ∗ dD dN ∗ = −ΓN ∗ + R, = ΓN ∗, rec = ΓN ∗ − D hσ v iρ (t) dt dt dt Dj Dj j j X Γ is N ∗ in matter width, N ∗(t = 0), D(t = 0) from statistical hadroniza- tion, and ρj(t) is the time dependent particle ‘j’ density: To obtain ∗ the observable resonance yield Nrec we integrate to the time t = τ spend by N ∗ in the opaque matter, and add the remainder from free INEL space decay. Regeneration term R ∝ hσDi vDiiρi negligible since production reactions very much weaker than scattering, {i} ¿ {j}. Hadronic matter acts as black cloud, practically all in matter decays cannot be reconstructed. J. Rafelski, Arizona The future of RHI Collisions Kielce, October 17, 2004, page 19

TWO resonance ratios combined natural widths spread ΓΣ∗ = 150 MeV 0 10 NA49 sudden 0.60 NA49 STAR STAR Γ =150 MeV Γ = Σ∗ Κ∗ 50 MeV Γ K*=50 MeV )

Γ = ) Σ∗ 35 MeV Λ T=200 Λ 0.40

/(all −1 /(all Thermally produced τ=1fm 10 T=175 T=200 MeV

T=150 (1385) (1385) ∗ ∗

Σ T=100 MeV T=125 Σ 0.20 τ=2 fm

T=100 MeV τ= τ=20 fm 3 fm ... −2 10 −3 −2 −1 0 0.00 10 10 10 10 0.00 0.20 0.40 0.60 * + * + K(892)/(all )K K(892)/(all )K Dependence of the combined Σ∗/(all Λ) with K∗(892)/(all K) signals on the chemical freeze-out temperature and HG phase lifetime.

Even the first rough measurement of K∗/K indicates that there is no long lived hadron phase. In matter widening makes this conclusion stronger. J. Rafelski, Arizona The future of RHI Collisions Kielce, October 17, 2004, page 20

Discovery: Azimuthal asymmetry of particle spectra

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, observed B. Wosiek. Quark scaling: Paul Sorenson and Huan-Zhong Huang. Idea due to J.-Y. Ollitrault. J. Rafelski, Arizona The future of RHI Collisions Kielce, October 17, 2004, page 21 Excursion to Statistical hadronization allows to explore the rate of production of pentaquarks which are very sensitive to chemical potentials: Θ+(1540)[uudds¯] (‘wrong strangeness’ baryon) and Ξ−−(1862)[ssqqq¯], Σ−(1776?)[sqqqq¯]. (PRC68, 061901 (2003), hep-ph/0310188)

Expected relative yield of Θ+(1540)(left); Ξ−−(1862) and Σ−(1776?) (right), based on statistical hadronization fits at SPS and RHIC: solid lines γs and γq fitted; dashed lines γs fitted, γq = 1; dotted lines γs = γq = 1. J. Rafelski, Arizona The future of RHI Collisions Kielce, October 17, 2004, page 22 Some issues in description of hadron yields 1. FAST phase transformation implies chemical nonequilibrium, see ‘Gadzic´ ki horn’: the phase space density is in general dif- ferent in the two phases. To preserve entropy (valance quark pair number) across the phases need a jump in the phase space occupancy parameters γi. This replaces the jump in volume in a slow reequilibration with mixed phase. 2. Incorporate the complete tree of resonance decays please note: not only for yields but also most important for spectra. 3. Production weight with width of the resonances accounts for experimental reaction rates Full analysis of experimental results requires a significant numer- ical effort. Short-cut projects produce results which alter physi- cal conclusions. For this reason the Krak´ow-Tucson collaboration produced a public package SHARE Statistical Hadronization with Resonances which is available e.g. at http://www.physics.arizona.edu/˜torrieri/SHARE/share.html (see talk by W. Broniowski)

IN FUTURE: we hope that the more accurate, standardized and debugged hadronization studies will reduce misunderstandings J. Rafelski, Arizona The future of RHI Collisions Kielce, October 17, 2004, page 23 FOUR QUARKS: s, s, q, q → FOUR CHEMICAL PARAMETERS

γi controls overall abundance Absolute chemical

of quark (i = q, s) pairs equilibrium

λi controls difference between Relative chemical

strange and non-strange quarks (i = q, s) equilibrium

HG-EXAMPLE: redistribution, production of strangeness Relative chemical equilibrium Absolute chemical equilibrium

s q q s q s q s

EXCHANGE REACTION PAIR PRODUCTION REACTION λi γi J. Rafelski, Arizona The future of RHI Collisions Kielce, October 17, 2004, page 24

Particle yields in chemical (non)equilibrium The counting of hadrons is conveniently done by counting the va- lence quark content (u, d, s, . . .), and it leads to characterization of HG equivalent to QGP phase. There is a natural relation of quark fugacities with hadron fugacities, for particle ‘i’

ni ki σi/T Υi ≡ Πiγi λi = e but for one complication: for historical reasons hyperon number is µb 3 µb/T 2 opposite to strangeness, thus µS = 3 − µs, where λq = e , λq = λuλd. Example of NUCLEONS: 3 µb/T 3 two particles N, N → two chemical factors, with λq = e , γN = γq ;

σN ≡ µb + T ln γN , σN ≡ −µb + T ln γN ;

µb/T −µb/T ΥN = γN e , ΥN = γN e . Meaning of parameters from e.g. the first law of thermodynamics:

dE + P dV − T dS = σN dN + σN dN

= µb(dN − dN) + T ln γN (dN + dN).

The (baryo)chemical potential µb controls the particle difference = baryon number. γ regulates the number of particle- pairs present. J. Rafelski, Arizona The future of RHI Collisions Kielce, October 17, 2004, page 25

STRANGENESS PRODUCTION: Theoretical perspective

STRANGENESS / NET BARYON NUMBER s/b Baryon number b is conserved, strangeness could increase slightly in hadroniza- tion. s/b ratio probes the mechanism of primordial fireball baryon deposition and strangeness production. Ratio eliminates dependence on reaction geometry.

STRANGENESS / ENTROPY CONTENT s/S Strangeness s and entropy S produced predominantly in early hot parton phase. Ratio eliminates dependence on reaction geometry. Strangeness and entropy could increase slightly in hadronization. s/S relation to K+/π+ is not trivial when precision better than 25% needed.

HADRON PHASE SPACE OVERPOPULATION

γs, γq allow correct measure of yields of strangeness and baryon number, probe dynamics of hadronization, allow fast breakup without ‘mixed phase’ J. Rafelski, Arizona The future of RHI Collisions Kielce, October 17, 2004, page 26 Instead: Marek Ga´zdzicki study of s¯/d¯ 〉 + π

〈 ¯

/ Rise of s¯ Rise of d 〉

+ decrease of baryon density K 〈 0.2

0.1

A+A: NA49 AGS p+p RHIC

0 2 1 10 10

sNN (GeV) The ‘peak’ is result of two effects: approach to saturation of strangeness, followed by reduction of baryon density which allows growth of d¯. To confirm this let us eliminate from the presented measurement the last effect: J. Rafelski, Arizona The future of RHI Collisions Kielce, October 17, 2004, page 27

Probing strangeness excitation by ratio K/π The particle yield products

+ − + − K ≡ K (us¯)K (us¯ ) ∝ λu/λs λs/λu π ≡ π (ud¯)π (ud¯ ) ∝ λu/λd λd/λu are muchpless dependent onp chemical conditionsqincluding baryonp density.

There is a notable enhance- central rapidity AA ment in K/π above the K+/π+ ratio recorded in pp reactions, which provides an upper limit on K/π. There is a clear 4π AA change in the speed of rise in the K/π ratio at the lower en- ergy limit at SPS; This com- bined with change in nuclear NN K+/π+ > K/π compression results in a peak in the K+/π+. J. Rafelski, Arizona The future of RHI Collisions Kielce, October 17, 2004, page 28

STRANGENESS vs NET BARYON CONTENT: requires fit to yield data

* AGS: s/b = 0.11

Strangeness per thermal baryon deposited within rapidity slice (RHIC) or par- ticipating in the reaction (AGS, SPS) grows rapidly and continuously. YIELD MUCH GREATER THAN IN NN-REACTIONS AGS with SHARE, other re- sults with earlier programs, soon SHARE. J. Rafelski, Arizona The future of RHI Collisions Kielce, October 17, 2004, page 29

Charm and bottom at LHC Given high energy threshold charm (and certainly bottom)heavy flavor is be- lieved to be produced predominantly in initial parton collisions and not in ther- mal relatively soft collisions. Will it thermalize?

Ycc¯ ' 150 − 300; Yb¯b ' 5 − 15 Precise prediction is a challenge to nLO pQCD since it requires parton distri- bution and initial time evolution within colliding nuclei. Thermal yields are at 10-30% for charm, negligible for b¯b.

No significant reannihilation expected in dense matter evolution. The phase space occupancy rises rapidly. The way it works: assuming effective thermaliza- tion of local distributions, the integral of the Boltzmann spectrum yields at each local temperature T :

m 3 g π N = k V T 3 γ (t) em/T (t), V T 3 = Const., k = . c c T (t) 2π2 2 sµ ¶ r Since at hadronization mc/T ' 10 and mb/T ' 30 the thermal yields need to be multiplied by large γc, or resp. γb to maintain the initially produced yield. We 2 expect ABOVE equilibrium yields. Since e.g. J/Ψ ∝ γc we expect multi charmed meson, baryon production enhancement. J. Rafelski, Arizona The future of RHI Collisions Kielce, October 17, 2004, page 30

Thermal Charm Example at LHC

thermal charm as function T , the time Total thermal charm yield as function dependent local temperature. of initial temperature. J. Rafelski, Arizona The future of RHI Collisions Kielce, October 17, 2004, page 31

Strangeness at LHC has some surprises At LHC fast dilution of initial high density phase. Strangeness is slower to reequilibrate chemically. Initial high yield preserved, this leads to overpopu- lation of phase space at hadronization. Here, let us estimate the maximum possible. Limits generated by condensation boundary. For , an m m −m 2 mπ K K π limits are: π : γq ≤ e T , K : γsγq ≤ e T → γs/γq ≤ e T → K/π

Expect a shift toward strange meson production. Aside of K/π shown, the en- hanced γs/γq will enhance other strange particles. J. Rafelski, Arizona The future of RHI Collisions Kielce, October 17, 2004, page 32

Is QGP discovered??

At SPS and RHIC: Predicted QGP behavior confirmed by strangeness and strange antibaryon enhancement which imply mobility. Enhanced source entropy content consistent with initial state thermal gluon degrees of freedom, also expected given strangeness enhancement. Chemical properties consistent with sudden hadron production in fast, filamenting breakup of QGP.

Furthermore at RHIC: quark coalescence explains features of non-azimuthally symmetric production. Early thermalization and strange quark participation in matter flow. Jet quenching indicates dense and highly absorptive matter.

Strangeness excitation function fingerprints QGP as the new state of matter: Probable onset of ‘valon’ quark deconfinement at AGS;

NEAR FUTURE The deconfinement specific hadronic ‘deep’ probe at LHC is charm and bottom flavor Search for deconfinement boundary next priority

Immediate FUTURE Wojtek Broniowski presents a vote of thanks