290 likes | 455 Views
DENSE QUARK MATTER IN A MAGNETIC FIELD. Vivian de la Incera. University of Texas at El Paso. CSQCD II Peking University, Beijing May 20-24, 2009. OUTLINE. Color Superconductivity CS in a Magnetic Field Magnetic Phases: MCFL, PCFL Conclusions. QCD Phases.
E N D
DENSE QUARK MATTER IN A MAGNETIC FIELD Vivian de la Incera University of Texas at El Paso CSQCD II Peking University, Beijing May 20-24, 2009
OUTLINE • Color Superconductivity • CS in a Magnetic Field • Magnetic Phases: MCFL, PCFL • Conclusions
QCD Phases The biggest puzzles lie in the intermediate regions RHIC Crystalline CS, Gluonic Phases, other? Magnetic Field
NEUTRON STARS ? • At the core • Super-High Densities (~ 10 times nuclear density) • Relatively Low Temperatures (T < 10 MeV) • High Magnetic Fields (probably larger than B~ 1015–1016G for core of magnetars) 4
COLOR SUPERCONDUCTIVITY Cooper instability at the Fermi surface Asymptotic freedom plus Formation ofQuark-Quark Pairs: ColorSuperconductivity Attractive interactions Bailin & Love, Phys Rep. ‘84
COLOR–FLAVOR LOCKED PHASE Rapp, Schafer, Shuryak and Velkovsky, PRL’98 Alford, Rajagopal and Wilczek, PLB ’98 Diquark condensate O=ODirac⊗Oflavor⊗Ocolor If density great enough, Ms can be neglected and 6
CFL MAIN FEATURES • All quark pair. No gapless fermions, no massless gluons. • Color superconductivity is more robust than conventional superconductivity (no need to resort to phonons). Hence is a high Tc superconductor. • Chiral symmetry is broken in an unconventional way: through the locking of flavor and color symmetries. 7
ROTATED ELECTROMAGNETISM d u u d u d s s s
ROTATED CHARGES The pairs are all -neutral, but the quarks can be neutral or charged - CHARGES s s s d d d u u u All-chargedquarks have integer charges
CFL SCALES At very large densities
MAGNETISM IN COLOR SUPERCONDUCTIVITY Can a magnetic field modify the Pairing Pattern? Can the CS produce a back reaction of the magnetic field? Can a color superconductor generate a magnetic field?
MCFL Ansatz only get contributions from pairs of neutral quarks get contributions from pairs of neutral and pairs of charged quarks Ferrer, V.I. and Manuel, PRL’05, NPB’06
NAMBU-GORKOV FIELDS IN NONZERO B , where the Gorkov fields separate by their rotated charge as and the corresponding Gorkov inverse propagators and contain the gaps:
GAP SOLUTIONS at LARGE MAGNETIC FIELD Ferrer, V.I. and Manuel, PRL’05, NPB’06
CFLVSMCFL SU(3)C × SU(3)L × SU(3)R × U(1)B SU(3)C × SU(2)L × SU(2)R × U(1)B × U(1)A • 9 Goldstone modes: charged and neutral. • 5 Goldstone modes: all neutral • Low energy MCFL similar to low density hadronic matter in a magnetic field. • Ferrer, VI and Manuel, PRL’05 NPB’06 • Low energy CFL similar to low density hadronic matter. • Schafer & Wilzcek, PRL’99
LOW ENERGY CFL THEORY IN A MAGNETIC FIELD B = 0 B 0 Ferrer & VI, PRD’07
LOW ENERGY THEORY IN A MAGNETIC FIELD The dispersion relations for the charged Goldstone bosons is Showing that the charged Goldstone bosons acquire a magnetic-field-induced mass For a meson to be stable its mass should be less than twice the gap, otherwise it could decay into a particle-antiparticle pair. Hence, CFLMCFL crossover Ferrer & VI, PRD’07
HAAS-VAN ALPHEN OSCILLATIONS OF THE GAP AND MAGNETIZATION Fukushima and Warringa, PRL’08 Noronha and Shovkovy, PRD’07
PARAMAGNETIC CFL Because of the modified electromagnetism, gluons are charged in the color superconductor Fields bigger than the square Meissner gluon mass induce an instability which is removed by the formation of a paramagnetic vortex state PCFL Ferrer & VI, PRL’06
PHASES IN THREE-FLAVORS THEORY CFL: SU(3)C SU(3)LSU(3)R U(1)B U(1)e.m. SO(3)rot SU(3)C+L+R U(1)e.m SO(3)rot Rapp, Schafer, Shuryak& Velkovsky, PRL’98 Alford, Rajagopal and Wilczek, PLB ‘98 MCFL: SU(3)C SU(2)LSU(2)R U(1)B U(-)(1)AU(1)e.m SO(2)rotSU(2)C+L+R U(1)e.m SO(2)rot Ferrer, V.I. and Manuel PRL’05; NPB ’06 PCFL:gluon condensate G4i iG5i& induced SU(3)C SU(2)L SU(2)R U(1)B U(-)(1)AU(1)e.m SO(2)rot SU(2)C+L+R U(1)e.m Ferrer & V.I. PRL ’06
MAGNETIC PHASES AT HIGH DENSITY E.J. Ferrer and V.I. Phys.Rev.D76:045011,2007 Chromomagnetic Instability
DIFFICULTIES OF THE STANDARD MAGNETAR MODEL Supernova remnants associated with magnetarsshould be an order of magnitude more energetic, but Recent calculations indicate that their energies are similar. When a magnetar spins down, the rotational energy output should go into a magnetized wind of ultra-relativistic electrons and positrons that radiate via synchrotron emission. So far nobody has detected the expected luminous pulsar wind nebulae around magnetars. Possible Alternatives: B can be boosted (Ferrer& VI, PRL’06) or even induced (Ferrer& VI, PRD’07; Son and Stephanov, PRD’08) by a CS core
Neutron stars provide a natural lab to explore the effects of B in CS What is the correct ground state at intermediate densities? Is it affected by the star’s magnetic field? Inhomogeneous Gluon Condensates, other field-related effects… Explore possible signatures of the CS-in-B phase in neutron stars CONCLUSIONS
SB and Dynamical Anomalous Magnetic Moment Let us consider a chiral theory (Massless QED, NJL etc.) Once the chiral symmetry is broken by the chiral condensate, any structure that breaks chiral symmetry is allowed in the full propagator. In the presence of a magnetic field, there will be then a dynamically generated mass and a dynamically generated anomalous magnetic moment. Induced Zeeman Effect
MCFL Ansatz only get contributions from pairs of neutral quarks get contributions from pairs of neutral and pairs of charged quarks
OUTLOOK • It seems to be a profound connection between magnetism and color superconductivity. More work needs to be done to explore this association at a deeper level and to establish a link between theory and astrophysical observations. • Connections between MCFL/PCFL and Quark-Nova Mechanism? • Ouyed et al. (this conference)