You can find this page at QUARTER: Fall 2008 LECTURES: 432 Phys/Geo, TR 2:10 to 3:30 INSTRUCTOR: Daniel Cebra, 539 P/G, , GRADERS: none TEXT: No required text. The following could be useful: R.L Vogt Ultrarelativistic Heavy Ion Collisions C.Y. Wong Introduction to High-Energy Heavy-Ion Collisions L.P. Csernai Introduction to Relativistic Heavy Ion Collisions J. Letessier and J. Rafelski Hadrons and Quark-Gluon Plasma HOMEWORK: There will be presentations assigned through the quarter. EXAM: There will be no exams for this course GRADE DETERMINATION: Grade will be determined presentations and class participation OFFICE HOURS: Cebra (any time) Course Overview: The class will be taught as a seminar class. We will alternate between lectures to overview the concepts with readings and discussions of critical papers in the field. There will be no homework assignments, no exams. Students are read the discussion papers ahead and to come prepared for presentations. PHYSICS 224C Nuclear Physics III - Experimental High Energy

Course Outline I.Overview and Historical Perspective a.Hagedorn Bootstrap Model b.Bjorken energy density c.Basic Kinematics I.Quantum Chromodynamics a.Asymptotic freedom b.Confinement c.Chirality d.Drell-yan II.Initial Conditions and First Collisions a.Glauber Model --- pre-collision and initial geometry (impact parameter) b.Color-Glass Condensate c.Parton Cascade --- I.Quark-Gluon Plasma Formation and Evolution a.Lattice QCD b.Hydrodynamics c.Elliptic flow II.Probes of the Dense Partonic Phase a.J/y Suppression and open charm b.Upsilon c.Jets d.Direct Photons e.Di-Leptons I.Hadronization a.Recombination vs. Fragmentation b.Chemical Equilibrium, Chemical freeze-out c.Strangeness enhancement II.Thermal Freeze-out a.Pion production/Entropy b.Radial Flow c.HBT I.Implications a.Big Bang Cosmology b.BBN c.Supernovae d.Neutron, Strange, and Quark Stars

Broad Historic Developments 6/26/20153Physics 224C – Lecture 1 -- Cebra 1896Discovery of Radioactivity (Becquerel) 1911Nuclear Atom (Rutherford) 1932Discovery of the neutron (Chadwick) 1935Meson Hypothesis (Yukawa) 1939Liquid-Drop model of nucear fission (Bohr and Wheeler) 1947Discovery of the pion (Powell) 1949Nuclear Shell Model (Mayer and Jensen) 1953Strangeness Hypothesis (Gell-Mann and Nishjima) 1953First production of strange particles (Brookhaven) 1955Discovery of the anti-proton (Chamberlain and Segre) 1964Quark model of hadrons (Gell-Mann and Zweig) 1967Electroweak model proposed (Weinberg and Salam) 1970Charm hypothesis (Glashow) 1974Discovery of the J/  (Ricther, Ting) 1977  Discovered and bottom inferred (Lederman) 1980First Quark Matter meeting (Darmstadt, Germany) 1983W and Z discovered (Rubbia) 1983Isabelle cancelled 1984RHIC Proposal 1986Heavy-ion operations at the AGS and SPS 1992Au beams at the AGS and Pb beams at the SPS 1995Top quark observed (Fermilab) 2000Au+Au operations at RHIC 2009?Pb+Pb operations at the LHC

A brief history of relativistic heavy-ion facilities 6/26/20154Physics 224C – Lecture 1 -- Cebra LBNL – Bevalac (1980 – 1992) [Au 0.1 to 1.15 AGeV] EOS --- TPCEOS --- TPC : DLS --- DiLepton spectrometer DLS --- DiLepton spectrometer GSI – SIS () [] TAPS : KaoS : FoPi BNL – AGS ( ) [Si, 1994 Au 10 AGeV, 8, 6, 4, 2] E802/866/917 ; E810/891 ; E877 ; E878; E864; E895 ; E CERN – SPS (1986-present) [O 60, 200 AGeV ( ); S 200 AGeV ( ): Pb 158, 80, 40, 30, 20 AGeV ( ), In] HELIOS(NA34) ; NA35/NA49/NA61(Shine) ; NA36; NA38/NA50/NA60; NA44 ; CERES(NA45); NA52 WA85/WA94/WA97/NA57 ; WA80/WA9898 BNL – RHIC (2000-present) [Au+Au 130, 200, 62.4, 19.6, d+Au 200, Cu+Cu 200, 62.4, 22, p+p 200, 450] STAR PHENIX Phobos BRAHMS pp2pp CERN – LHC (2009?)[Pb+Pb] ALICE CMS ATLAS

Quark-Gluon Plasma 6/26/20155Physics 224C – Lecture 1 -- Cebra

Motivation for Relativistic Heavy Ion Collisions Two big connections: cosmology and QCD

The phase diagram of QCD Temperature baryon density Neutron stars Early universe nuclei nucleon gas hadron gas colour superconductor quark-gluon plasma TcTc 00 critical point ? vacuum CFL

Evolution of Forces in Nature

Age Energy Matter in universe GeV grand unified theory of all forces s10 14 GeV1 st phase transition (strong: q,g + electroweak: g, l,n) s10 2 GeV2 nd phase transition (strong: q,g + electro: g + weak: l,n) s0.2 GeV3 rd phase transition (strong:hadrons + electro:g + weak: l,n) 3 min.0.1 MeVnuclei 6*10 5 years0.3 eVatoms Now ( 1.5*10 9 years) 3*10 -4 eV = 3 K Going back in time… RHIC, LHC & FAIR RIA & FAIR

Connection to Cosmology Baryogenesis ? Dark Matter Formation ? Is matter generation in cosmic medium (plasma) different than matter generation in vacuum ?

Sakharov (1967) – three conditions for baryogenesis Baryon number violation C- and CP-symmetry violation Interactions out of thermal equilibrium Currently, there is no experimental evidence of particle interactions where the conservation of baryon number is broken: all observed particle reactions have equal baryon number before and after. Mathematically, the commutator of the baryon number quantum operator with the Standard Model hamiltonian is zero: [B,H] = BH - HB = 0. This suggests physics beyond the Standard Model The second condition — violation of CP-symmetry — was discovered in 1964 (direct CP-violation, that is violation of CP-symmetry in a decay process, was discovered later, in 1999). If CPT- symmetry is assumed, violation of CP-symmetry demands violation of time inversion symmetry, or T-symmetry. The last condition states that the rate of a reaction which generates baryon-asymmetry must be less than the rate of expansion of the universe. In this situation the particles and their corresponding antiparticles do not achieve thermal equilibrium due to rapid expansion decreasing the occurrence of pair-annihilation.

Dark Matter in RHI collisions ? Possibly (not like dark energy) The basic parameters: mass, charge

Sudden expansion, fluid fills empty space without loss of energy. dE = 0 PdV > 0 therefore dS > 0 Gradual expansion (equilibrium maintained), fluid loses energy through PdV work. dE = -PdV therefore dS = 0 Isentropic Adiabatic Hot Cool Basic Thermodynamics

Nuclear Equation of State

Golden Rule 1: Entropy per co-moving volume is conserved Golden Rule 3: All chemical potentials are negligible Golden Rule 2: All entropy is in relativistic species Expansion covers many decades in T, so typically either T>>m (relativistic) or T<<m (frozen out) Golden Rule 4:

g *S 1 Billion o K 1 Trillion o K Start with light particles, no strong nuclear force

g *S 1 Billion o K 1 Trillion o K Previous Plot Now add hadrons = feel strong nuclear force

g *S 1 Billion o K 1 Trillion o K Previous Plots Keep adding more hadrons….

Density of hadron mass states dN/dM increases exponentially with mass. Prior to the 1970’s this was explained in several ways theoretically Statistical Bootstrap Hadrons made of hadrons made of hadrons… Regge Trajectories Stretchy rotators, first string theory Broniowski, et.al T H ~ 2  o K How many hadrons?

Rolf Hagedorn German Hadron bootstrap model and limiting temperature (1965) Ordinary statistical mechanics For thermal hadron gas (somewhat crudely): Energy diverges as T --> T H Maximum achievable temperature? “…a veil, obscuring our view of the very beginning.” Steven Weinberg, The First Three Minutes (1977) Hagedorn Limiting Temperature

What do I mean “Bjorken”? yy Increasing E y’=y-y beam 0 dN/dy’ “Inside-out” & 1 dimensional Boost-invariant

Impact of “Bjorken” dN/dy distribution is flat over a large region except “near the target”. v 2 is independent of y over a large region except “near the target”. (2d-hydro.) p T (y) described by 1d or 2d-hydro. Usual HBT interpretation starts from a boost- invariant source. T(t) described by 1d-hydro. Simple energy density formula X X

Notations We’ll be using the following notations: proper time and rapidity

Most General Boost Invariant Energy-Momentum Tensor The most general boost-invariant energy-momentum tensor for a high energy collision of two very large nuclei is (at x 3 =0) which, due to gives There are 3 extreme limits.

Limit I: “Free Streaming” Free streaming is characterized by the following “2d” energy-momentum tensor: such that and  The total energy E~  is conserved, as expected for non-interacting particles.

Limit II: Bjorken Hydrodynamics In the case of ideal hydrodynamics, the energy-momentum tensor is symmetric in all three spatial directions (isotropization): such that Using the ideal gas equation of state,, yields Bjorken, ‘83  The total energy E~  is not conserved, while the total entropy S is conserved.

Most General Boost Invariant Energy-Momentum Tensor Deviations from the scaling of energy density, like are due to longitudinal pressure, which does work in the longitudinal direction modifying the energy density scaling with tau.  Non-zero positive longitudinal pressure and isotropization If then, as, one gets. ↔ deviations from

Limit III: Color Glass at Early Times In CGC at very early times such that, since we get, at the leading log level, Energy-momentum tensor is (Lappi, ’06)

Karsch, Redlich, Tawfik, Eur.Phys.J.C29: ,2003  /T 4  g *S D. Gross H.D. Politzer F. Wilczek American QCD Asymptotic Freedom (1973) “In 1972 the early universe seemed hopelessly opaque…conditions of ultrahigh temperatures…produce a theoretically intractable mess. But asymptotic freedom renders ultrahigh temperatures friendly…” Frank Wilczek, Nobel Lecture (RMP 05) QCD to the rescue! Replace Hadrons (messy and numerous) by Quarks and Gluons (simple and few) Hadron gas Thermal QCD ”QGP” (Lattice)

Nobel prize for Physics 2005 Kolb & Turner, “The Early Universe” QCD Transition e + e - Annihilation Nucleosynthesis Decoupling Mesons freeze out Heavy quarks and bosons freeze out “Before [QCD] we could not go back further than 200,000 years after the Big Bang. Today…since QCD simplifies at high energy, we can extrapolate to very early times when nucleons melted…to form a quark-gluon plasma.” David Gross, Nobel Lecture (RMP 05) Thermal QCD -- i.e. quarks and gluons -- makes the very early universe tractable; but where is the experimental proof? g *S

The main features of Quantum Chromodynamics Confinement – At large distances the effective coupling between quarks is large, resulting in confinement. – Free quarks are not observed in nature. Asymptotic freedom – At short distances the effective coupling between quarks decreases logarithmically. – Under such conditions quarks and gluons appear to be quasi-free. (Hidden) chiral symmetry – Connected with the quark masses – When confined quarks have a large dynamical mass - constituent mass – In the small coupling limit (some) quarks have small mass - current mass

Quarks and Gluons

Basic Building Blocks ala Halzen and Martin

Quark properties ala Wong

What do we know about quark masses ? Why are quark current masses so different ? Can there be stable (dark) matter based on heavy quarks ?

Elementary Particle Generations

Some particle properties

Elemenary particles summary

Comparing QCD with QED (Halzen & Martin)

Quark and Gluon Field Theory == QCD (I)

Quark and Gluon Field Theory == QCD (II)

Quark and Gluon Field Theory == QCD (III) Boson mediating the q-qbar interaction is the gluon. Why 8 and not 9 combinations ? (analogy to flavor octet of mesons) – R-Bbar, R-Gbar, B-Gbar, B-Rbar, G-Rbar, G-BBar – 1/sqrt(2) (R-Rbar - B-Bbar) – 1/sqrt(6) (R-Rbar + B-Bbar – 2G-Gbar) – Not: 1/sqrt(3) (R-Rbar + G-Gbar + B-Bbar) (not net color)

Hadrons

QCD – a non-Abelian Gauge Theory

Particle Classifications

Quarks

Theoretical and computational (lattice) QCD In vacuum: - asymptotically free quarks have current mass - confined quarks have constituent mass - baryonic mass is sum of valence quark constituent masses Masses can be computed as a function of the evolving coupling Strength or the ‘level of asymptotic freedom’, i.e. dynamic masses. But the universe was not a vacuum at the time of hadronization, it was likely a plasma of quarks and gluons. Is the mass generation mechanism the same ?

Confinement Represented by Bag Model

Bag Model of Hadrons

Comments on Bag Model

Still open questions in the Standard Model

Why RHIC Physics ?