Finite Density Lattice Gauge Theories with Positive Fermion Determinants (Two-color QCD at finite density and finite isospin model)

概要

論文の詳細を見る
We perform simulations of (3-colour) QCD with 2 quark flavours at a finite chemical potential μ_I for isospin (I_3), and of 2-colour QCD at a finite chemical potential μ for quark number. At zero temperature, QCD at finite μ_I has a mean-field phase transition at μ_I=m_π to a superfluid state with a charged pion condensate which spontaneously breaks I_3. We study the finite temperature transition as a function of μ_I. For μ_I<m_π, where this is closely related to the transition at finite μ, this appears to be a crossover independent of quark mass, with no sign of the proposed critical endpoint. For μ_I>m_π this becomes a true phase transition where the pion condensate evaporates. For μ_I just above m_π the transition seems to be second order, while for larger μ_I it appears to become first order. At zero temperature, 2-colour QCD also possesses a superfluid state with a diquark condensate. We study its spectrum of Goldstone and pseudo-Goldstone bosons associated with chiral and quark-number symmetry breaking.
理論物理学刊行会の論文
2004-05-31