Quark confinement in a random background Gross-Neveu model
نویسنده
چکیده
We study an extended Gross-Neveu model with Nf quark flavors and with an additional SU(2) (global color) degree of freedom of the quarks. The four fermion interaction in the color channel is mediated by a random color matrix with fixed strength. The effective potential for the quark condensate and the scalar correlation function is investigated in the large Nf -limit. Quark antiquark thresholds are absent in the scalar correlation function implying that the decay of the scalar meson in free quarks is avoided. The transition from the low energy to the high energy perturbative regime is found to be smooth. Perturbation theory provides a good description of Green’s functions at high energies, although there is no quark liberation. ∗ Supported in part by DFG under contracts La–932/1− 1/2.
منابع مشابه
Quark Confinement due to Random Interactions
On the level of an effective quark theory, we define confinement by the absence of quark anti-quark thresholds in correlation functions. We then propose a confining Nambu-Jona-Lasinio-type model. Its four fermion interaction in the color channel is mediated by a random color matrix. We study the model's phase structure as well as its behavior under extreme conditions, i.e. high temperature and/...
متن کاملMesons a in Collinear QCD Model
A phenomenological model for the quark structure of mesons is considered. The model is based on the tube model for QCD, where all quanta with nonzero transverse momenta are neglected. In the limit that the mass term of the gluons goes to infinity, the model is equivalent to a combination of the ’t Hooft and Gross-Neveu models and can be solved semianalytically. The model has the properties of c...
متن کاملStrange Form Factors, the a-Term and Strange Quark Distributions in the Gross-Neveu Model
For NC -+ 00 the structure function of physical fermions in the Gross-Neveu model is of pure valence type. Nevertheless several strange form factors of u-quarks, including the induced magnetic moment and the a-term acquire substantial O(Ni) contributions from virtual ss pairs. Those arise from matrix elements which are off-diagonal in Fock space, i.e. they do not have a simple interpretation in...
متن کاملDuality between quark-quark and quark-antiquark pairing in 1+1 dimensional large N models
A few years ago, Chodos, Minakata and Cooper [1] proposed a 1+1 dimensional field theoretical model which can be solved in the 1/N -expansion and illustrates nicely the phenomenon of Cooper pairing. Independently, the same model has been analyzed by Kleinert and Babaev [2] at finite N in 2+ǫ dimensions, in a somewhat different context. It is closely related to the Gross-Neveu model [3] from whi...
متن کاملRenormalon disappearance in Borel sum of the 1 / N expansion of the Gross - Neveu model mass gap
The exact mass gap of the O(N) Gross-Neveu model is known, for arbitrary N , from non-perturbative methods. However, a “naive” perturbative expansion of the pole mass exhibits an infinite set of infrared renormalons at order 1/N , formally similar to the QCD heavy quark pole mass renormalons, potentially leading to large O(Λ) perturbative ambiguities. We examine the precise vanishing mechanism ...
متن کامل