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THE ROLE OF MAGNETIC FIELDS IN DENSE QUARK MATTER. Vivian de la Incera. University of Texas at El Paso. OUTLINE. Color Superconductivity Color Superconductivity in a Magnetic Field: Magnetic CFL Magnetic-Field-Induced Gluon Condensate: Paramagnetic CFL
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THE ROLE OF MAGNETIC FIELDS IN DENSE QUARK MATTER Vivian de la Incera University of Texas at El Paso
OUTLINE • Color Superconductivity • Color Superconductivity in a Magnetic Field: Magnetic CFL • Magnetic-Field-Induced Gluon Condensate: Paramagnetic CFL • Chromomagnetic Instabilities at Intermediate Densities (unstable gapped 2SC) • Solution to the CI in 2SC: Spontaneous Generation of GC and B • 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)
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
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.
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 on 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
MAGNETIC EFFECTS ON THE GLUONS EJF & de la Incera,PRL 97 (2006) 122301 Because of the modified electromagnetism, gluons are charged in the color superconductor Charged Gluon Sector of Mean-Field Effective Action in CFL:
MAGNETIC FIELD INDUCED INSTABILITY IN CHARGED SPIN-ONE FIELDS Assuming that there is an external magnetic field in the z-direction, one mode becomes unstable when with corresponding eigenvector: “Zero-mode problem” for non-Abelian gauge fields whose solution is the formation of a vortex condensate of charged spin-1 fields. Nielsen & Olesen NPB 144 (1978) Skalozub, Sov.JNP23 (1978);ibid 43 (1986) Ambjorn & Olesen, NPB315 (1989)
PARAMAGNETIC CFL Minimum Equations: + Magnetic Antiscreening Abrikosov's Equation
DIFFERENT BEHAVIOR in a B Conventional Superconductor H < Hc H ≥ Hc PCFL MCFL Color Superconductor H ≥ Hc H < Hc
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
CHROMOMAGNETIC INSTABILITIES IN 2SC Color Neutrality and beta equilibrium Gluons Masses Stable Gapped 2SC a=1,2,3massless a=4,5,6,7 positive a=8positive Unstable Gapped 2SC a=1,2,3massless a=4,5,6,7 negative a=8positive Gapless 2SC a=1,2,3massless a=4,5,6,7 negative a=8 negative Huang/Shovkovy, PRD 70 (2004) 051501
CHROMOMAGNETIC INSTABILITIES IN 2SC Huang/Shovkovy, PRD 70 (2004) 051501 charged gluons 8th gluon µ8 Tachyonic Mode of Charged Gluons At
GLUON CONDENSATE AND INDUCED MAGNETIC FIELD Solutions: The gluon condensate generates a magnetic field E.J. Ferrer and V.I. , Phys.Rev.D76:114012, 2007.
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
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? • (CSQCD II conference)