标题： 重子密度与膨胀的手征夸克模型 显示英文标题

标题： Baryon Density and the Dilated Chiral Quark Model

摘要： 我们利用包含QCD迹异常的手征夸克模型摄动地计算了密度对强子性质的影响，以考察在有限密度下构造洛伦兹不变拉氏量的可能性。 我们用热场论技术在一环阶计算了组分夸克、标量场和π介子的密度相关质量。 在手征极限下，π介子在有限密度下仍保持无质量。 发现蝌蚪型修正导致随着重子密度增加而质量减小，而辐射修正则引入洛伦兹对称破缺项。 我们发现在大 $N_c$ 极限且标量质量较大时，蝌蚪项占主导地位，平均场近似是可靠的，产生一个洛伦兹不变的拉氏量，并且随着重子密度的增加质量减小。 显示英文摘要

摘要： We calculate perturbatively the effect of density on hadronic properties using the chiral quark model implemented by the QCD trace anomaly to see the possibility of constructing Lorentz invariant Lagrangian at finite density. We calculate the density dependent masses of the constituent quark, the scalar field and the pion in one-loop order using the technique of thermo field dynamics. In the chiral limit, the pion remains massless at finite density. It is found that the tadpole type corrections lead to the decreasing masses with increasing baryon density, while the radiative corrections induce Lorentz-symmetry-breaking terms. We found in the large $N_c$ limit with large scalar mass that the tadpoles dominate and the mean-field approximation is reliable, giving rise a Lorentz-invariant Lagrangian with masses decreasing as the baryon density increases.