We study the static responses of cold quark matter in the intermediate baryonic density region(characterized by a chemical potentialμ) in the presence of a strong-magnetic field. We consider inparticular, the so-called magnetic dual Chiral Density Wave (MDCDW) phase, which is materialized by aninhomogeneous condensate formed by a particle-hole pair. It is shown, that the MDCDW phase is morestable in the weak-coupling regime than the one considered in the magnetic catalysis of chiral symmetrybraking phenomenon and even than the chiral symmetric phase that was expected to be realized atsufficiently high baryonic chemical potential. The different components of the photon polarization operatorof the MDCDW phase in the one-loop approximation are calculated. We found that in the MDCDW phasethere is neither Debye screening nor Meissner effect in the lowest-Landau-level approximation. Theobtained Debye length depends on the amplitudemand modulationbof the inhomogeneous condensateand it is only different from zero if the relation |μ−b|>m holds. But, we found that in the region ofinterest this inequality is not satisfied. Thus, no Debye screening takes place under those conditions. On theother hand, since the particle-hole condensate is electrically neutral, the U(1) electromagnetic group is notbroken by the ground state and consequently there is no Meissner effect. These results can be of interest forthe astrophysics of neutron stars
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Effect of Strong Magnetic Field on Competing Order Parameters in Two-Flavor Dense Quark Matter
We study the effect of strong magnetic field on competing chiral and diquark order parameters in a regime of moderately dense quark matter. The interdependence of the chiral and diquark condensates through nonperturbative quark mass and strong coupling effects is analyzed in a two-flavor Nambu-Jona-Lasinio (NJL) model. In the weak magnetic field limit, our results agree qualitatively with earlier zero-field studies in the literature that find a critical coupling ratio G D / G S ~ 1.1 below which chiral or superconducting order parameters appear almost exclusively. Above the critical ratio, there exists a significant mixed broken phase region where both gaps are nonzero. However, a strong magnetic field B ≳ 1 0 18 G disrupts this mixed broken phase region and changes a smooth crossover found in the weak-field case to a first-order transition for both gaps at almost the same critical density. Our results suggest that in the two-flavor approximation to moderately dense quark matter strong magnetic field enhances the possibility of a mixed phase at high density, with implications for the structure, energetics, and vibrational spectrum of neutron stars.
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- Award ID(s):
- 1608959
- NSF-PAR ID:
- 10024397
- Date Published:
- Journal Name:
- Advances in High Energy Physics
- Volume:
- 2017
- ISSN:
- 1687-7357
- Page Range / eLocation ID:
- 1 to 11
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1155/2017/6472909
