New color-magnetic defects in dense quark matter

Abstract

Color-flavor locked (CFL) quark matter expels color-magnetic fields due to the Meissner effect. One of these fields carries an admixture of the ordinary abelian magnetic field and therefore flux tubes may form if CFL matter is exposed to a magnetic field, possibly in the interior of neutron stars or in quark stars. We employ a Ginzburg-Landau approach for three massless quark flavors, which takes into account the multi-component nature of color superconductivity. Based on the weakcoupling expressions for the Ginzburg-Landau parameters, we identify the regime where CFL is a type-II color superconductor and compute the radial profiles of different color-magnetic flux tubes. Among the configurations without baryon circulation we find a new solution that is energetically preferred over the flux tubes previously discussed in the literature in the parameter regime relevant for compact stars. Within the same setup, we also find a new defect in the 2SC phase, namely magnetic domain walls, which emerge naturally from the previously studied flux tubes if a more general ansatz for the order parameter is used. Color-magnetic defects in the interior of compact stars allow for sustained deformations of the star, potentially strong enough to produce detectable gravitational waves. * Electronic address: ahaber@hep.itp.tuwien.ac.at † Electronic address: a.schmitt@soton.ac.uk

Magnetic monopoles with internal structure

“…In Fig. 1, we depict the solution (16) and the energy density (17). We use this source to generate the magnetic permeability controlled by the function…”

“…(19) with the source field given by Eq. (16). We depict a planar section of the energy density passing through the center of the structure, with the darkness of the color directly related to the intensity of the energy density.…”

“…The solutions H(r) (ascending line) and K(r) (descending line) of Eqs (19). (left) with the source field given by(16) and the corresponding energy density of the monopole (right).…”

Small and hollow magnetic monopoles

“…Another motivation comes from the possibility that magnetic monopoles in specific materials [15] can support an electric dipole and, in this sense, may be endowed with internal structure. We also think that the current investigation is of interest to describe other possibilities, such as the enlarged system that couples a superconductor to a superfluid recently investigated in [16] and also, the presence of color-magnetic defects [17] recently found in dense quark matter, that are energetically preferred in the parameter regime relevant for compact stars.…”

Vortices in a Generalized Maxwell-Higgs Model with Visible and Hidden Sectors

“…We are also thinking of enlarging the model to accommodate other symmetries, such as the SU (2) × U (1) symmetry, to explore the presence of solutions within the non-Abelian context examined before in [35], and also the SU (3) × U (1) symmetry, to investigate color-magnetic structures in the dense quark matter scenario explored recently in [56]. The presence of non-Abelian symmetries makes the problem much harder, so the search for first order differential equations that solve the equations of motion is of current interest and would be welcome.…”