New View of the QCD Phase Diagram Unconfined World Unconfined World Quarkyonic World Confined World O(1) Confined World O(1) Conventional Wisdom Krzysztof Redlich (Wroclaw, GSI) Chihiro Sasaki (Munich) Rob Pisarski and Yoshimasa Hidaka BNL RBRC Large N Will argue real world looks more like large N
Mesons: quark-antiquark, Non-Interacting, masses ~ Baryons: N quarks, masses ~ , baryon interactions ~ Brief Review of Large N Spectrum of Low Energy Baryons: Multiplets with I = J; I,J = 1/2 -> I,J = N/2 The confined world has no baryons! About 20 degenerate lowest mass baryons
Confinement at Finite Density: Generates Debye Screening => Deconfinement at Tc Quark loops are always small by 1/N_c For finite baryon fermi energy, confinement is never affected by the presence of quarks! T_c does not depend upon baryon density!
No baryons in the confined phase for Unconfined World For weakly coupled gas of quarks. Quarkyonic World Confined World O(1) Large N Finite Baryon Density: If T < T_c, no free gluons, degrees of freedom are ~ Nc Quarkyonic Matter: Confined gas of perturbative quarks! Confined: Mesons and Glueballs Quarkyonic: Quarks and Glueballs Unconfined: Quarks and Gluons
Some Properties of Quarkyonic Matter Quarks inside the Fermi Sea: Perturbative Interactions => At High Density can use perturbative quark Fermi gas for bulk properties At Fermi Surface: Interactions sensitive to infrared => Confined baryons Perturbative high density quark matter is chirally symmetric but confined => violates intuitive arguments that confinement => chiral symmetry Quarkyonic matter appears (at T= 0) when
Baryons are non-relativistic: Nuclear physics is in a width of order 1/N around the baryon mass! 2 c Width of the Transition Region: Large Nc world looks like our world: Nuclear matter is non-relativistic, and there is a narrow transition between confined and quarkyonic world
Nf/Nc fixed, large Nc Confinement not an order parameter Baryon number is Large density of states: Number of Lowest mass baryons Straight line in temperature-chemical potential plane
As baryon chemical potential increases: Hadronic World => Quarkyonic Matter Hadronic World: Confined world of very weakly interacting mesons. At low As T increases from Hadronic world => Quark Gluon Plasma Quarks Gluons Goldstone Bosons Quarks Goldstone Bosons Mesons and glueballs Great Wall of Weakly Interacting Mesons Mesons and glueballs Great Wall of Strongly Interacting Lowest Mass Baryons => Triple point where walls meet
The Non-Perturbative Fermi Surface: Deep in the Fermi sea, a momentum of order the Fermi momenta must be exchanged in interactions Near the Fermi surface, interactions are strong Excitations are confined and color singlet If form a bound state with negative biding energy => Chiral condensate Condensate breaks translational invariance => crystal Chiral symmetry breaking of order Quarkyonic phase at most weakly breaks chiral symmetry Might be parity double and chiral symmetric
Conclusions: There are three phases of QCD at large N: Confined Unconfined Quarkyonic They have very different bulk properties There may be a tri-critical point somewhere near AGS energies The early observations of Cleymans, Redlich,Braun-Munzinger and Stachel strongly support that this picture reflects N = 3.