2005/10/22 by Kenji Fukushima, Fukushima, Kenji
Earth and Planetary Sciences · Engineering · Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #High-pressure geophysics and materials #Pulsars and Gravitational Waves Research #Superconducting Materials and Applications
paper · pdf · doi:10.48550/arxiv.hep-ph/0510299
openalex publication_date 2005/10/22 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We address the phase structure of color superconducting quark matter at high quark density. Under the electric and color neutrality conditions there appear various phases as a result of the Fermi surface mismatch among different quark flavors induced by finite strange quark mass; the color-flavor locked (CFL) phase where quarks are all energy gapped, the u-quark superconducting (uSC) phase where u-quarks are paired with either d- or s-quarks, the d-quark superconducting (dSC) phase that is the d-quark analogue of the uSC phase, the two-flavor superconducting (2SC) phase where u- and d-quarks are paired, and the unpaired quark matter (UQM) that is normal quark matter without pairing. Besides these possibilities, when the Fermi surface mismatch is large enough to surpass the gap energy, the gapless superconducting phases are expected. We focus our discussion on the chromomagnetic instability problem related to the gapless CFL (gCFL) onset and explore the instability regions on the phase diagram as a function of the temperature and the quark chemical potential. We sketch how to reach stable physical states inside the instability regions.