ANALYTIC STRUCTURE OF SCABS COMPOSITES IN THE SYMMETRICAL PHASE OF THE GAUGED NAMBU-JONA-LASINIO MODEL

The gauged Nambu-Jona-Lasinio model in the quenched-ladder approximati on has nontrivial dynamics near a critical scaling region (critical cu rve) separating a chiral symmetric and a dynamically chiral symmetry b roken phase. Scalar and pseudoscalar composites corresponding to the f our-fermion and gauge interactions become relevant degrees of freedom at long distances, which is reflected in the appearance of a large ano malous dimension of the four-fermion operators. A method is introduced for solving the Schwinger-Dyson equation for the Yukawa vertex in spe cific kinematic regimes. This allows one to derive an analytic express ion for the scalar propagator, which is valid along the entire critica l curve. The mass and width of the scalar composites in the critical s caling region are reexamined and the conformal phase transition at gau ge coupling alpha(0)=alpha(c) is discussed.