Eight-quark interactions as a chiral thermometer

Abstract

A NJL Lagrangian extended to six and eight quark interactions is applied to study temperature effects (SU(3) flavor limit, massless case), and (realistic massive case). The transition temperature can be considerably reduced as compared to the standard approach, in accordance with recent lattice calculations. The mesonic spectra built on the spontaneously broken vacuum induced by the 't Hooft interaction strength, as opposed to the commonly considered case driven by the four-quark coupling, undergoes a rapid crossover to the unbroken phase, with a slope and at a temperature which is regulated by the strength of the OZI violating eight-quark interactions. This strength can be adjusted in consonance with the four-quark coupling and leaves the spectra unchanged, except for the sigma meson mass, which decreases. A first order transition behavior is also a possible solution within the present approach.

4 pages, 4 figures, prepared for the proceedings of Quark Matter 2008 - 20th International Conference on Ultra-Relativistic Nucleus Nucleus Collisions, February 4-10, Jaipur (India)

References in corpus (8)

• The order of the quantum chromodynamics transition predicted by the standard model of particle physics
• Multi-quark interactions with a globally stable vacuum
• Effects of eight-quark interactions on the hadronic vacuum and mass spectra of light mesons
• Chiral phase transition in an extended NJL model with higher-order multi-quark interactions
• Lowering the critical temperature with eight-quark interactions
• Inverse Mass Expansion of the One-Loop Effective Action
• Aspects of U_A(1) breaking in the Nambu and Jona-Lasinio model
• OZI violating eight-quark interactions as a thermometer for chiral transitions