Abstract
The spectrum of meson and diquark excitations of dense color neutral cold quark matter is investigated in the framework of a two-flavored Nambu–Jona-Lasinio–type model, including a quark - and color -chemical potential. It was found that, in the color superconducting (2SC) phase, i.e. at , acquires rather small values in order to ensure the color neutrality. In this phase the and meson masses are evaluated around . The spectrum of scalar diquarks in the color neutral 2SC phase consists of a heavy [-singlet] resonance with mass , four light diquarks with mass , and one Nambu-Goldstone boson, which is in accordance with the Goldstone theorem. Moreover, in the 2SC phase there are five light stable particles as well as a heavy resonance in the spectrum of pseudoscalar diquarks. In the color symmetric phase, i.e. for , a mass splitting of scalar diquarks and antidiquarks is shown to arise if , contrary to the case of , where the masses of scalar antidiquarks and diquarks are degenerate at the value . If the coupling strength in the pseudoscalar diquark channel is the same as in the scalar diquark one (as for QCD-inspired Nambu–Jona-Lasinio models), then in the color symmetric phase pseudoscalar diquarks are not allowed to exist as stable particles.
- Received 5 May 2005
DOI:https://doi.org/10.1103/PhysRevD.72.056007
©2005 American Physical Society