标题： 强耦合下的晶格规范理论与重子 显示英文标题

标题： Lattice gauge theory with baryons at strong coupling

摘要： 我们研究了非零重子密度情况下强耦合格点QCD的有效哈密顿量。在主阶近似下，有效哈密顿量是一个广义反铁磁体。对于 naïve 费米子，对称性为 U(4N_f)，自旋属于一个依赖于局域重子数的表示。哈密顿量中的次近邻项将对称性破坏为 U(N_f) × U(N_f)。我们将量子问题转化为一个欧几里得 σ 模型，并在 1/N_c 展开中对其进行分析。在真空扇区，我们恢复了最近邻和次近邻理论的自发对称性破缺。对于非零重子密度，我们仅研究最近邻理论，并证明自发对称性破缺的模式依赖于重子密度。 显示英文摘要

摘要： We study the effective Hamiltonian for strong-coupling lattice QCD in the case of non-zero baryon density. In leading order the effective Hamiltonian is a generalized antiferromagnet. For naive fermions, the symmetry is U(4N_f) and the spins belong to a representation that depends on the local baryon number. Next-nearest-neighbor (nnn) terms in the Hamiltonian break the symmetry to U(N_f) x U(N_f). We transform the quantum problem to a Euclidean sigma model which we analyze in a 1/N_c expansion. In the vacuum sector we recover spontaneous breaking of chiral symmetry for the nearest-neighbor and nnn theories. For non-zero baryon density we study the nearest-neighbor theory only, and show that the pattern of spontaneous symmetry breaking depends on the baryon density.