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COLOR SUPERCONDUCTIVITY and MAGNETIC FIELD: Strange Bed Fellows in the Core of Neutron Stars?. Vivian de la Incera Western Illinois University. IRGAC 2006. Barcelona, Spain, July 11-15, 2006. Neutron Stars. Diameter:. Mass:. Density:. Magnetic fields:.
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COLOR SUPERCONDUCTIVITY and MAGNETIC FIELD: Strange Bed Fellows in the Core of Neutron Stars? Vivian de la Incera Western Illinois University IRGAC 2006 Barcelona, Spain, July 11-15, 2006
Neutron Stars Diameter: Mass: Density: Magnetic fields: B~ 1012 – 1014 G in the surface of pulsars B~ 1015 – 1016 G in the surface of magnetars IRGAC 2006
Outline • Color Superconductivity • Magnetic Field and Color Superconductivity • MCFL: Symmetry, gap structure, gap solutions • Conclusions and Outlook • E.J. Ferrer, V.I. and C. Manuel, • PRL 95, 152002 ; NPB 747, 88. IRGAC 2006
ColorSuperconductivity Bailin and Love ‘84 IRGAC 2006
Three flavors at very high density: CFL phase Pairs: spin zero, antisymmetric in flavor and color Rapp, Schafer, Shuryak and Velkovsky, ‘98 Alford, Rajagopal and Wilczek, ‘98 IRGAC 2006
Magnetic Field Inside a Color Superconductor In spin-zero color superconductivity a linear combination of the photon and one gluon remains massless (in-medium electromagnetic field). An external magnetic field penetrates the superconductor in the form of a “rotated” field (no Meissner effect) - CHARGES s s s d d d u u u All-chargedquarks have integer charges All pairs are -neutral IRGAC 2006
ColorSuperconductivity & B Will a magnetic field reinforce color superconductivity? IRGAC 2006
Dominant attractive interactions in 3-flavor QCD lead to a general order parameter of the form CFL: SU(3)CX SU(3)L X SU(3)R X U(1)BX U(1)e.m. SU(3)C+L+RX U(1)e.m Rapp, Schafer, Shuryak and Velkovsky, PRL 81 (1998) Alford, Rajagopal and Wilczek, PLB 422 (1998) B 0 B = 0 MCFL: SU(3)C X SU(2)LX SU(2)R X U(1)B X U(1)e.mX U(-)(1)ASU(2)C+L+R X U(1)e.m Ferrer, V.I. and Manuel PRL 95,152002 IRGAC 2006
Three-flavor NJL Theory with Rotated Magnetic Field
MCFL ansatz including subdominant interactions only get contributions from pairs of neutral quarks get contributions from pairs of neutral and pairs of charged quarks IRGAC 2006
The mean-field action can be written as: where the Gorkov fields are defined by: and the Gorkov inverse propagators are IRGAC 2006
Gap Equations IRGAC 2006
For fields the gap equations can be reduced to IRGAC 2006
Gap Solutions IRGAC 2006 Ferrer, V.I. and Manuel, NPB 747, 88
The magnetic field “helps” CS. The field reinforces the gap that gets contributions from pairs of -charged quarks. • The physics behind MCFL is different from the phenomenon of magnetic catalysis. In MCFL the field reinforces the diquark condensate through the modification of the density of state IRGAC 2006
CFLvs MCFL • 9 Goldstone modes: charged and neutral. • 5 Goldstone modes: all neutral • Low energy similar to low density QCD in a magnetic field. • Ferrer, VI and Manuel, NPB’06 • Low energy similar to low density QCD.Schafer & Wilzcek’ PRL 82 (1999) IRGAC 2006
CONCLUSIONS and OUTLOOK • Neutron stars provide a natural lab to explore the effects of B in CS • Is MCFL the correct state at intermediate, more realistic, magnetic fields? Gluon condensates? • What is the correct ground state at intermediate densities; is it affected by the star’s magnetic field? • Explore possible signatures of the CS-in-B phase in neutron stars: neutrino cooling, thermal conductivity, etc. IRGAC 2006