2维SU(N_C)格点规范理论中夸克真空凝聚

Quark Condensate in Two-Dimensional SU(N_C) Lattice Gauge Theory with Massive Wilson Quarks

用改进的Wilson夸克格点哈密顿量和变分法研究2维SU(N_C)规范场中夸克真空凝聚(?)与夸克质量m_q和Wilson参数r的依赖关系．结果表明：对于给定的r,当N_C=2,3,4,5,6,7,…时,(ψ)_(sub)a/ (gN_C^(3/2))的值随m_q的增大而减小．对于较大的N_C(如N_C＞3),当m_q很小时,(ψ)_(sub)a/(gN_C^(3/2))对r的依赖性很小,但随着m_q的增大,(ψ)_(sub)a/(gN_C^(3/2))对r的依赖性增大,且(ψ)_(sub)a/(gN_C^(3/2))的值随r的增大而增大；特别是,当m_q→0时,本文的格点结果与Zhitnitsky的连续理论分析结果(在弱耦合相中)很好地一致,这意味着本文在m_q≠0时所得到的结果是可靠的．

Using the improved lattice Hamiltonian with massive Wilson quark and the variational method, we study the quark mass mq and the Wilson parameter r dependences of the quark condensate （^ψψ） in the two-dlmensional SU（Nc） lattice gauge theory. The numerical results show that when r is given, for Nc=2, 3, 4, 5, 6, 7,…, the value of （^ψψ）suba/（gNc^3/2） decreases as mq increases. For Nc 〉3, when mq is small,（^ψψ）suba/（gNc^3/2） is almost independent of r; when mq is large, （^ψψ）suba/（gNc^3/2） increases with increasing r. Particularly, when mq→0, our numerical results agree very well with Zhitnitsky＇s analytical weak coupling result in the continuum, which implys that our numerical results in the case of mq ≠ 0 are reliable.