Mei Huang Paramagnetic Meissner Effect in the g

黄梅 Mei Huang Paramagnetic Meissner Effect in the g 2 SC Phase Mei Huang 黄 梅 Institute for Theoretical Physics, Frankfurt University Collaborate with I. Shovkovy ``The QCD-phase diagram”, Skopelos, May 29 – June 2, 2004

黄梅 Mei Huang QCD Phase Diagram: from weak to strong coupling Based on T. Hatsuda’s talk (1. 5 -2) Tc Tc Strongly interacting matter GSI ? M. H, S. Scherer, H. Weber, M. Bleicher, H. Stoecker BEC BCS Crossover from BCS to BEC ?

It is possible that CS exists in the core of compact stars Charge neutrality ! 1. Global charge neutrality: 2. mixed phase M. Buballa, I. Shovkovy, M. Hanauske, M. H Phys. Rev. D 67: 103004, 2003 2. Local charge neutrality: 3. homogeneous phase g 2 SC: M. H. , P. F. Zhuang, W. Q. Chao Phys. Rev. D 67: 0650152, 2003 I. Shovkovy, M. H Phys. Lett. B 564: 205, 2003 M. H, I. Shovkovy Nucl. Phys. A 729: 835, 2003 黄梅 Mei Huang

黄梅 Mei Huang Whether Cooper pairing will be destroyed by mismatch?

黄梅 Mei Huang -equilibrium : ur ug ub dr dg db

§ 黄梅 Mei Huang SU(2) NJL Model

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黄梅 Mei Huang Whethere is still Cooper pairing ?

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Gluon self-energy in g 2 SC M. H. , I. Shovkovy, hep-ph/0406…, will appear in ar. Xiv 黄梅 Mei Huang

黄梅 Mei Huang Debye Mass: Meissner Mass:

黄梅 Mei Huang Special properties of g 2 SC 1. Pairing quarks have different number densities at T=0 2. Finite temperature properties: nonmonotonic behavior not a BCS ratio

黄梅 Mei Huang 1 -3 gluons 8 gluon 4 -7 gluons

黄梅 Mei Huang 1 -3 gluons 8 gluon 4 -7 gluons Meissner Masses for the 8 th gluon and 4 th-7 th are negative!!!

How to understand the minus sign? Meissner Effect 黄梅 Mei Huang

黄梅 Mei Huang Why Meissner Effect in regular superconductor ? Response function: related to matter’s properties Induced current External Field

黄梅 Mei Huang Paramagnetic current and diamagnetic current 1. Normal metal 2. free eletrons 2. Superconductor 3. BCS pair, gap parameter Perfect Diamagnet

黄梅 Mei Huang 3. Paramagnetic Meissner Effect Mesoscopic superconductors: a) A loop made of three crystals of HTSC; b) Aluminium disc

黄梅 Mei Huang in small superconductors Nature 396, 144 - 146 (1998); doi: 10. 1038/24110 mixed state of Y–Ba–Cu–O ceramics Low Temperature Physics (1996) -- V 22, 539 -541 J. Phys. : Condens. Matter 9 (1997) L 525 -L 531 …. . .

Paramagnetic contributions 黄梅 Mei Huang Paramagnetic contribution

黄梅 Mei Huang Summary 1. Cold-dense charge neutral 2 -flavor quark matter at intermediate coupling region is in g 2 SC phase, it is a thermal stable state. 2. Unstable chromo-magnetic gluon modes appear in g 2 SC phase. 3. Paramagnetic Meissner effect ! 4. Spontaneous magnetization ? 5. Need gluon condensate to stabilize ?