Location: Cyclotron Building (434), Seminar Room
Dr. Andrei Kryjevski, Seattle
Meson Condensates in CFL Superconductors
Abstract:
I will discuss properties of quark matter at asymptotically high baryon number density in the presence of non-zero quark masses and will present results of some recent calculations.
1. Working near the chiral limit, O(alpha_s) corrections to the squared masses of the pseudo Nambu-Goldstone excitations due to chiral symmetry breaking were considered and it was found that these contributions tended to destabilize the symmetric Color Flavor Locked (CFL) vacuum, leading to a surprisingly complex phase structure for quark matter as a function of quark masses. In particular, two new meson condensed phases of matter possibly relevant for the real world were found.
2. Extending previously existing analysis based on perturbative expansion in quark masses, free energy of CFL quark matter at non-zero strange quark mass including dynamics of pseudo Nambu-Goldstone bosons was calculated. It was demonstrated that the K0 condensed state (CFLK0) had lower free energy than the symmetric CFL state for the values of strange quark mass up to the point of the CFL-gapless CFL (gCFL) phase transition. Also, the spectrum of the fermionic quasiparticle excitations about the kaon condensed ground state was calculated. In particular, it was found that i. CFLK0 had only one gapless fermionic mode, compared to the two gapless modes found in the symmetric CFL case, and ii. the CFL-gCFL transition critical value of strange quark mass was higher than the previously reported symmetric CFL state value.
I will conclude by outlining description of gCFL phase including the non-trivial flavor alignment in the ground state (time permitting).