Suggested Course Layout Move class from 3 days a week to 2 days a week Proposal: Mo 2-4 p.m., Tu 11 a.m.-1 p.m. Jan8,9: week1 – Intro and kinematic variables Jan15,16: Bormio Winter Workshop, no class Jan 22,23: weeks 2 & 3 – Spacetime evolution of asymptotic freedom Jan 29,30: week 4 – thermal and hydromodels Feb 5,6: week 5 – pQCD in QGP physics Feb 12,13: Big Sky Winter Workshop, no class Feb 19,20: week 6 – lattice QCD Feb 26,27: weeks 7 & 8 – initial conditions and complete modeling Mar 5,6: week 9 – bulk signatures and properties Mar 12,13: Spring Break, no class Mar 19,20: week 10 – rare particle production Mar 26,27: week 11 – high momentum probes Apr 2,3: week 12 – RHIC and its detectors Apr, 9,10: week 13 – essays (I) Apr 16,17: week 14 – essays (II) Apr 23: overflow

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

The phase diagram of QCD Early universe quark-gluon plasma critical point ? Tc Temperature colour superconductor hadron gas nucleon gas nuclei CFL r0 Neutron stars vacuum baryon density

Evolution of Forces in Nature

RHIC, LHC & FAIR RIA & FAIR Going back in time… Age Energy Matter in universe 0 1019 GeV grand unified theory of all forces 10-35 s 1014 GeV 1st phase transition (strong: q,g + electroweak: g, l,n) 10-10 s 102 GeV 2nd phase transition (strong: q,g + electro: g + weak: l,n) 10-5 s 0.2 GeV 3rd phase transition (strong:hadrons + electro:g + weak: l,n) 3 min. 0.1 MeV nuclei 6*105 years 0.3 eV atoms Now 3*10-4 eV = 3 K (15 billion years) 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

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

Nuclear Equation of State

Nuclear Equation of State

Golden Rule 1: Entropy per co-moving volume is conserved 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 3: All chemical potentials are negligible Golden Rule 4:

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

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

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

How many hadrons? Density of hadron mass states dN/dM increases exponentially with mass. TH ~ 21012 oK Broniowski, et.al. 2004 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

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

QCD to the rescue! Replace Hadrons (messy and numerous) D. Gross H.D. Politzer F. Wilczek Replace Hadrons (messy and numerous) by Quarks and Gluons (simple and few) American QCD Asymptotic Freedom (1973) e/T4  g*S Thermal QCD ”QGP” (Lattice) “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) Hadron gas Karsch, Redlich, Tawfik, Eur.Phys.J.C29:549-556,2003

Nobel prize for Physics 2005 “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) g*S Thermal QCD -- i.e. quarks and gluons -- makes the very early universe tractable; but where is the experimental proof? n Decoupling Nucleosynthesis e+e- Annihilation Heavy quarks and bosons freeze out QCD Transition Mesons freeze out Kolb & Turner, “The Early Universe”

The main features of Quantum Chromodynamics (QCD) 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 ?

Why RHIC Physics ?