标题： 共形SU(N)规范理论的物理谱 显示英文标题

标题： The Physical Spectrum of Conformal SU(N) Gauge Theories

摘要： 我们研究了具有近红外耦合但高于共形相变临界值的矢量型SU(N)规范理论的物理谱。 我们利用色散关系、动力学费米子质量的动量依赖性以及共振饱和性。 我们表明，第二谱函数求和规则受到连续区贡献的显著影响，与类似QCD的理论相比，这允许轴矢量-矢量质量分裂减小。 在技术彩色理论中，这一特性可能导致弱电S参数的小值甚至负值贡献。 显示英文摘要

摘要： We investigate the physical spectrum of vector-like SU(N) gauge theories with infrared coupling close to but above the critical value for a conformal phase transition. We use dispersion relations, the momentum dependence of the dynamical fermion mass and resonance saturation. We show that the second spectral function sum rule is substantially affected by the continuum contribution, allowing for a reduction of the axial vector - vector mass splitting with respect to QCD-like theories. In technicolor theories, this feature can result in a small or even negative contribution to the electroweak S parameter.