Figure'2.25'from'page'92'of' Exploring*the*Heart*of*Ma2er* - PowerPoint PPT Presentation

Figure'2.25'from'page'92'of' Exploring*the*Heart*of*Ma2er* Temperature Early Universe The Phases of QCD LHC Experiments RHIC Experiments R H I C E n e r g y Quark-Gluon Plasma S c a n Crossover Future FAIR Experiments ~170 MeV s 1 t o r d e r p h a s e t r a n s Critical Point i t i o n Color Hadron Gas Superconductor Nuclear Vacuum Neutron Stars Matter 0 MeV 0 MeV 900 MeV Baryon Chemical Potential FIGURE 2.25 The phase diagram of QCD is shown as a function of baryon chemical potential (a measure of the matter to antimatter excess) and temperature. A prominent feature in this landscape is the location of the critical point, which indicates the end of the first-order phase transition line in this plane. SOURCE: DOE/NSF, Nuclear Science Advisory Committee, 2007, The Frontiers of Nuclear Science: A Long Range Plan.

QCD Phase Diagram Big Bang T Quark Gluon Plasma RHIC SPS Supernova Hadron Gas Nuclear Liquid Color Superconductivity Neutron Stars µ ( ρ ) From'Thomas'Schaefer,'NC'State'

More'phase'diagrams'of'QCD'.'.'.'

What is QCD? What is a Phase of QCD? What is a Phase Diagram? Phase Diagram: Equilibrium state as a function of thermodynamic (or other: m q , N c , N f , B ) variables. Here : Ω ( T, µ, V ) = − V P ( µ, T ) • Other choices of independent variables: G ( P, T, N ) , . . . • At T = 0 have µ = E ( N q + 1) − E ( N q ) . • In real experiments control parameters are more compli- cated (beam energy E cm , impact parameter b ( → N ch ), system size A ). From'Thomas'Schaefer,'NC'State'

Pressure'vs.'Temperature'for'3'“substances”'

Thermodynamic'PotenFals' • Use'the'thermodynamic'potenFal' appropriate'to'the'system:'what'is'held' fixed?''If'S,V,N'then'use'internal'energy'U.' • At'equilibrium,'the'appropriate' thermodynamic'potenFal'is'minimized,' which'determines'the'phase;'e.g.,'S,V,N' constant' ! 'U'minimized;'T,V,μ'constant' ! 'Ω'minimized.' • For'the'grand'potenFal'Ω,'phase' boundaries'have'equal'temperature'T'and' chemical'potenFal(s)'μ'for'each'phase.'

What is QCD (Quantum Chromo Dynamics)? Elementary fields: Quarks Gluons ⎧ color a = 1 , . . . , 3 ⎧ ⎪ color a = 1 , . . . , 8 ⎪ ⎨ ⎨ ( q α ) a A a spin α = 1 , 2 f µ � ± spin ⎪ ⎩ µ ⎪ flavor f = u, d, s, c, b, t ⎩ Dynamics: Generalized Maxwell (Yang-Mills) + Dirac theory / − m f ) q f − 1 4 G a µ ν G a L = ¯ q f ( iD µ ν G a µ ν = ∂ µ A a ν − ∂ ν A a µ + gf abc A b µ A c ν / q = γ µ � i ∂ µ + gA a µ t a � iD q From'Thomas'Schaefer,'NC'State'

“Seeing” Quarks and Gluons ALEPH DALI Run=9063 Evt=7848 Run=15768 Evt=5906 Filename: DC015768_005906_960828_1338.PS_2J_3J Made on 28-Aug-1996 13:39:06 by DREVERMANN with DALI_D7. e + q e + q g q q e − e − From'Thomas'Schaefer,'NC'State'

Jet'Quenching'in'RelaFvisFc'Heavy[Ion'Collisions'(at'LHC)' • LHC'usually'collides'protons'on'protons' • Four'weeks'each'year'switches'to'Pb[Pb' • Principal'component'of'ALICE'detector'is'a'Fme' projecFon'chamber'(TPC).'Wikipedia:'“consists' of'a'gas[filled'detecFon'volume'in'an'electric' field'with'a'posiFon[sensiFve'electron'collecFon' system.'The'original'design'(and'the'one'most' commonly'used)'is'a'cylindrical'chamber'with' mulF[wire'proporFonal'chambers'(MWPC)'as' endplates.'' ALICE'detector' • RHIC:'Au'on'Au'at'100'GeV/A' • LHC:'Pb'on'Pb'at'2'TeV/A!' • Jets'lose'energy'traversing'the' fireball' ! 'jet'quenching' • Amount'of'quenching'gives' info'about'the'QGP'

Jet'Quenching'in'RelaFvisFc'Heavy[Ion'Collisions'(at'RHIC)' From:'hfps://www.star.bnl.gov/central/focus/highPt/'