New View of the QCD Phase Diagram
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Transcript of New View of the QCD Phase Diagram
New View of the QCD Phase Diagram
Krzysztof Redlich (Wroclaw, GSI)
Chihiro Sasaki (Munich)
Rob Pisarski and Yoshimasa Hidaka
BNL RBRC
Confined World
O(1)
Unconfined World
Conventional Wisdom
Will argue real world looks more like large N
Unconfined World
Confined World
O(1)
Quarkyonic World
Large N
Conjectured Phase Diagram for Nc = 3
Brief Review of Large N
Mesons: quark-antiquark, Non-Interacting, masses ~
Baryons: N quarks, masses ~ , baryon interactions ~
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!
Finite Baryon Density:
No baryons in the confined phase for
For weakly coupled gas of quarks.
If T < T_c, no free gluons, degrees of freedom are ~ Nc
Unconfined World
Confined World
O(1)
Quarkyonic World
Large N
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
Width of the Transition Region:
Baryons are non-relativistic:
Nuclear physics is in a width of order 1/N around the baryon mass!2
c
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
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Straight line in temperature-chemical potential plane
As T increases from Hadronic world => Quark
Gluon Plasma
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Quarks
Great Wall of Weakly Interacting Mesons
Hadronic World:
Confined world of very weakly interacting mesons. At low
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Mesons and glueballs
As baryon chemical potential increases:
Hadronic World => Quarkyonic MatterQuickTime™ and a decompressorare needed to see this picture.Quarks
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Mesons and glueballs
Great Wall of Strongly Interacting Lowest Mass Baryons =>
Triple point where walls meet
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With Redlich and Sasaki
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The Non-Perturbative Fermi Surface:
Deep in the Fermi sea, a momentum of order the Fermi momenta must be exchanged in interactions
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Near the Fermi surface,QuickTime™ and a
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Excitations are confined and color singletIf form a bound state with negative biding energy =>
Chiral condensate
Condensate breaks translational invariance => crystal
Chiral symmetry breaking of order QuickTime™ and a decompressorare needed to see this picture.
Quarkyonic phase at most weakly breaks chiral symmetry
Might be parity double and chiral symmetric
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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.