STRANGENESS AND THE DISCOVERY OF QUARK GLUON PLASMA Bloomington, November 30, 2004 Decon¯nement of quarks and gluons into a plasma (QGP) at high temperature is a predicted paradigm shifting feature of strong interactions. The production of strange particles in relativistic heavy ion collisions at CERN and BNL con¯rms that a new phase of matter with the expected properties is being formed. I will survey the key theoretical predictions and the related experimental results. Time permitting, I will discuss how the newly gained knowledge leads to the study of the hot nearly matter-antimatter symmetric post quark-gluon Universe. +50% of content is for STUDENTS. BONUS material after 50 transparencies: THE QUARK UNIVERSE 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 STRANGENESS AND THE DISCOVERY OF QUARK GLUON PLASMA Bloomington, November 30, 2004,page 2 EXPERIMENTAL HEAVY ION PROGRAM | LHC CERN: LHC opens after 2007 and SPS resumes after 2009 J. Rafelski, Arizona STRANGENESS AND THE DISCOVERY OF QUARK GLUON PLASMA Bloomington, November 30, 2004,page 3 ...and at BROOKHAVEN NATIONAL LABORATORY Relativistic Heavy Ion Collider: RHIC J. Rafelski, Arizona STRANGENESS AND THE DISCOVERY OF QUARK GLUON PLASMA Bloomington, November 30, 2004,page 4 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: Beam Energy = 100 GeV/u U-line 9 GeV/u No. Bunches = 57 High Int. Proton Source BAF (NASA) µ g-2 9 Q = +79 No. Ions /Bunch = 1×10 LI NAC T = 10 hours BOOSTER store L = 2 × 1026 cm-2 sec -1 Pol. Proton Source ave AGS HEP/NP 1 MeV/u Q = +32 TANDEMS Relativistic Heavy Ion Collider: RHIC J. Rafelski, Arizona STRANGENESS AND THE DISCOVERY OF QUARK GLUON PLASMA Bloomington, November 30, 2004,page 5 The origin of this research program STRUCTURED VACUUM: Melt the vacuum structure and demonstrate mobility of quarks { `decon¯nement'. 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 nucleons formed from elementary de- grees of freedom (quarks, gluons) at about 10-40¹s after big bang. 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 STRANGENESS AND THE DISCOVERY OF QUARK GLUON PLASMA Bloomington, November 30, 2004,page 6 What is decon¯nement? 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 con¯ned and decon¯ned phases of matter: phase diagram. Decon¯nement expected at both: high temperature and at high matter density. In a ¯nite 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 ¯rst principles and not as descriptive method of hadronization dynamics and ¯nal hadron yields, 3) More sensitive (hadronic and other) signatures of decon¯nement beware: ¯nal particles always hadrons, many decay into leptons DECONFINEMENT NOT A `NEW PARTICLE', there is no answer to journalists question: How many new vacuua have you produced today? J. Rafelski, Arizona STRANGENESS AND THE DISCOVERY OF QUARK GLUON PLASMA Bloomington, November 30, 2004,page 7 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 G¹º = 2 [B~ 2 E~ 2] ; h j ¹ºj i ´ ¹º a a ¡ a a a ®s 2 2 X 4 X 4 we have V G V (2:3 0:3)10¡ GeV = [390(12) MeV] ; h j ¼ j i ' § and V uu¹ + dd¹ V = 2[225(9) MeV]3 : h j j 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 j j i Vacuum is thought to generate color charge con¯nement: 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 STRANGENESS AND THE DISCOVERY OF QUARK GLUON PLASMA Bloomington, November 30, 2004,page 8 Do we understand how annihilation of almost all matter-antimatter occurs? Visible Matter Density [g cm−3 ] 1027 1015 103 10−9 1 TeV LHC 1016 quarks combine RHIC atoms antimatter form disappears 1 GeV photons 1013 neutrinos decouple SPS decouple nuclear reactions: light nuclei formed 1 MeV era of 1010 galaxies and stars 7 Particle energy 1 keV 10 Temperature [K] OBSERVATIONAL COSMOLOGY 1 eV 104 PARTICLE/NUCLEAR ASTROPHYSICS 10 10−12 10−6 1 106 1012 1018 day year ky My today Time [s] J. Rafelski, Arizona STRANGENESS AND THE DISCOVERY OF QUARK GLUON PLASMA Bloomington, November 30, 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 NA35 1986: S{Ag at 200AGeV 12 TEMPERATURE T0; Tf 300{250, 175{145 MeV; 300MeV 3.5 10 K ' J. Rafelski, Arizona STRANGENESS AND THE DISCOVERY OF QUARK GLUON PLASMA Bloomington, November 30, 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 STRANGENESS AND THE DISCOVERY OF QUARK GLUON PLASMA Bloomington, November 30, 2004,page 11 TWO STEP HADRON FORMATION MECHANISM IN QGP Ω 1. GG ss¹ (thermal gluons collide) ! GG cc¹ (initial parton collision) u s s s ! u u g s gluon dominated reactions u d d d s s s s 2. hadronization of pre-formed d g d g s g u g u s; s;¹ c; c¹ 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;¹ c; c¹ d g u quarks made in di®erent microscopic s s u reactions; this is signature of quark Ξ mobility and independent action, thus of decon¯nement. Enhance- ment of flavored (strange, charm) antibaryons progressing with `exotic' flavor content. AVAILABLE RESULT (SPS, RHIC): Enhancement of strange (anti)baryons progresses with strangeness content. J. Rafelski, Arizona STRANGENESS AND THE DISCOVERY OF QUARK GLUON PLASMA Bloomington, November 30, 2004,page 12 Why Strangeness is a diagnostic tool EXPERIMENTAL REASONS ² There are many strange particles allowing to study di®erent physics questions (q = u; d): Á(ss¹); K(qs¹); K(q¹s); ¤(qqs); ¤(q¹q¹s¹); ¥(qss); ¥(q¹s¹s¹); ­(sss); ­(s¹s¹s¹) : : : resonances : : : ² Strange hadrons are subject to a self analyzing de- cay within a few cm from the point of production; π π Ξ Λ p ² Production rates hence statistical signi¯cance is high; (strong interaction reaction cross sections) J. Rafelski, Arizona STRANGENESS AND THE DISCOVERY OF QUARK GLUON PLASMA Bloomington, November 30, 2004,page 13 THEORETICAL CONSIDERATIONS ² production of strangeness in gluon fusion GG ss¹ strangeness linked to gluons from QGP; ! (a) g (b) s (c) s g s dominant processes: g GG ss¹ abundant strangeness! g s g =evidence for gluons g s s q (d) s 10{15% of total rate: qq¹ ss¹ ! q s ² coincidence of scales: ms Tc ¿s ¿ ' ! ' QGP ! strangeness a clock for QGP phase ² s¹ q¹ strange antibaryon enhancement at'RHIC! (anti)hyperon dominance of (anti)baryons. J. Rafelski, Arizona STRANGENESS AND THE DISCOVERY OF QUARK GLUON PLASMA Bloomington, November 30, 2004,page 14 (MULTI)STRANGE (ANTI)HYPERON ENHANCEMENT WA97: central 158 A GeV Pb - Pb 10 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 de¯ned 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 STRANGENESS AND THE DISCOVERY OF QUARK GLUON PLASMA Bloomington, November 30, 2004,page 15 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.