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Hot Gold : Life at a Trillion Degrees

Hot Gold : Life at a Trillion Degrees. Paul Stankus Oak Ridge Nat’l Lab Vanderbilt REU, July ‘07. Our approach: Applied Laziness. Solid, liquid, vapor; old stuff…. 1337 o K. 3129 o K. (Somewhat higher at constant volume). Ludwig Boltzmann Austrian.

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Hot Gold : Life at a Trillion Degrees

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  1. HotGold: Life at a Trillion Degrees Paul Stankus Oak Ridge Nat’l Lab Vanderbilt REU, July ‘07

  2. Our approach: Applied Laziness

  3. Solid, liquid, vapor; old stuff…. 1337 oK 3129 oK (Somewhat higher at constant volume)

  4. Ludwig Boltzmann Austrian Distributions in classical statistical mechanics (1877) Outermost electrons partially ionized 103oK ~ 0.1 eV Nearly all electrons fully ionized 107oK ~ 1000 eV (Electron-Ion) Plasma k (11,600 oK)  1eV E

  5. Nuclei change and come apart Colliding nuclei change identities Kepler’s Supernova (SN 1604) remnant ~ 1 MeV 1010oK Disassemble nuclei completely ~ 8 MeV 1011oK

  6. Thermal wavelength One photon per wavelength3 Electrons/ positrons log(e) e/T4 Photons T4 Nuclei log(kT) log(kT) 109oK Radiation-Matter equivalence in Gold ~ 0.1 MeV Photon gases

  7. 1 Billion oK 1 Trillion oK 1012oK  e/T4 me mm Start with light particles, no strong nuclear force

  8. 1 Billion oK 1 Trillion oK 1012oK  e/T4 Previous Plot Now add hadrons = feel strong nuclear force

  9. 1 Billion oK 1 Trillion oK 1012oK  e/T4 Previous Plots Keep adding more hadrons….

  10. How many hadrons? Density of particle mass states dNPart/dM increases exponentially with mass. Broniowski, et.al. 2004 TH ~ 21012oK Prior to the 1970’s this was explained in several ways theoretically Statistical Bootstrap Hadrons made of hadrons made of hadrons… Regge TrajectoriesStretchy rotators, first string theory

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

  12. QCD to the rescue! 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 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 21012oK 170 MeV

  13. EM Plasma Strong self-interactions Quark-Gluon Plasma Non-ideal gases Atom e/T4 Ideal Quark-Gluon Gas Thermal QCD ”QGP”(Lattice) Hadrons

  14. National Research Council Report (2003) Eleven Science Questions for the New Century Question 8 is:

  15. BNL-RHIC Facility Also:BNL-AGS, CERN-SPS, CERN-LHC

  16. Side-to-beam view STAR Experiment at RHIC Hot Zone Along-the-beam view Au+Au at √sNN = 200 GeV

  17. Jet Jet Jet 80% Depletion! Jet Jet-Medium Interaction? PHENIX PRL88 (2002) 022301 Dense Medium Absorption Side-to-beam Parton Parton Along-the-beam

  18. Pedestal&flow subtracted Away-side Disappearance STAR PRL 91, 072304 (2003) Along-the-beam view Jet Jet Jet Proton-Proton Collision Nucleus-Nucleus Collision

  19. Pair opening angle Trigger particle Cherenkov cones? Mach cones? Suggestive of…

  20. Early High Fast Slow Later Elliptic momentum anisotropy Low High Initial (10-24 sec) Thermalized Medium Density, Pressure Pressure Gradient Low

  21. Fluid dynamics predicts momentum anisotropy correctly for 99% of particles produced in Au+Au What does it mean? PHENIX Data • Strong self-re-interaction • Early thermalization (10-24 sec) • Low dissipation (viscosity) • Equation of stateP/rsimilar to relativistic gas

  22. Ideal gas Ideal fluid Long mfp Short mfp High dissipation Low dissipation Data imply (D. Teaney): lMean Free Path~lde Broglie Quantum Limit! “Perfect Fluid!”

  23. Beam energy Anisotropy increases with increasing beam energy & energy density What does it mean? • High acceleration requires high P/rpressure/energy density. Hagedorn picture would be softer since massive hadrons are non-relativistic. • Increase/saturate with higher energydensities. In Hagedorn picture pressure decreases with density.

  24. Thermal photon radiation from quarks and gluons? Direct photons from nuclear collisions suggest initial temperatures > TH Ti> 500 MeV 51012oK

  25. Summary: The States of Gold 1012oK 103oK 106oK 109oK Solid L Vapor EM Plasma g gas g e+e- gas QGP We think we’ve created T>1012 oK matter in the lab It’s apparently very dense (opaque to high-E partons) It apparently thermalizes very quickly (self-interaction) It apparently behaves as a nearly-perfect fluid (very low viscosity, near quantum lower limit)

  26. Conclusions • Describing high-temperature matter is straightforward, if you’re lazy enough. • Strong interaction/hadron physics made it hard to understand T > 100 MeV ~ 1012 K;QCD theory rescues high temperatures. • We are only now delivering on a 30-year-old promise to test it experimentally. Matter with T > ~ 1012 K has been created in the lab and displays many surprising properties.

  27. Backup material

  28. “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”

  29. The QCD quark-hadron transition is typically ignored by cosmologists as uninteresting Weinberg (1972): Considers Hagedorn-style limiting-temperature model, leads to a(t)t2/3|lnt|1/2; but concludes “…the present contents…depends only on the entropy per baryon…. In order to learn something about the behavior of the universe before the temperature dropped below 1012oK we need to look for fossils [relics]….” Kolb & Turner (1990): “While we will not discuss the quark/hadron transition, the details and the nature (1st order, 2nd order, etc.) of this transition are of some cosmological interest, as local inhomogeneities in the baryon number density could possible affect…primordial nucleosythesis…”

  30. T(t) a(t) r(t) t How do we relate T to a,r? i.e. thermodynamics

  31. a(t)  a Friedmann-Robertson-Walker (FRW) cosmology Three basic solutions for a(t): • Relativistic gas, “radiation dominated” P/r = 1/3 ra-4a(t)t1/2 2. Non-relativistic gas, “matter dominated” P/r = 0 ra-3a(t)t2/3 3. “Cosmological-constant-dominated” or “vacuum-energy-dominated” P/r = -1 rconstant a(t)eHt“de Sitter space”

  32. The New Standard Cosmology in Four Easy Steps Inflation, dominated by “inflaton field” vacuum energy Radiation-dominated thermal equilibrium Matter-dominated, non-uniformities grow (structure) Start of acceleration in a(t), return to domination by cosmological constant and/or vacuum energy. w=P/r +1/3 accdec t -1/3 -1 aeHt at1/2 at2/3 now

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

  34. 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 1: Entropy per co-moving volume is conserved Golden Rule 3: All chemical potentials are negligible Golden Rule 4:

  35. Electron-Positron pairs appear 2me 1010oK ~ 1 MeV Mass of e+e- pair

  36. Ideal gas Ideal fluid Long mfp Short mfp High dissipation Low dissipation Data imply (D. Teaney): lMean Free Path~lde Broglie Quantum Limit! “Perfect Fluid!” Sakharov criteria for baryogenesis B violation C,CP violation Out of equilibrium Most of the early universe is QCD! Dissipation could be relevant here:

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