A Non-Principal Value Prescription for the Temporal Gauge

A non-principal value prescription is used to define the spurious singularities of Yang-Mills theory in the temporal gauge. Typical one-loop dimensionally-regularized temporal-gauge integrals in the prescription are explicitly calculated, and a regularization for the spurious gauge divergences is introduced. The divergent part of the one-loop self-energy is shown to be local and has the same form as that in the spatial axial gauge with the principal-value prescription. The renormalization of the theory is also briefly mentioned.Comment: 13 pages, NCKU-HEP/93-0

The UL(3)×UR(3)U_L(3) \times U_R(3) Extended Nambu--Jona-Lasinio Model in Differential Regularization

We employ the method of differential regularization to calculate explicitly the one-loop effective action of a bosonized $U_L(3)\times U_R(3)$ extended Nambu--Jona-Lasinio model consisting of scalar, pseudoscalar, vector and axial vector fields.Comment: LaTeX, 17 page

Baryon wave function in large-Nc QCD: Universality, nonlinear evolution equation and asymptotic limit

The 1/Nc expansion is formulated for the baryon wave function in terms of a specially constructed generating functional. The leading order of this 1/Nc expansion is universal for all low-lying baryons [including the O(1/Nc) and O(Nc^0) excited resonances] and for baryon-meson scattering states. A nonlinear evolution equation of Hamilton-Jacobi type is derived for the generating functional describing the baryon distribution amplitude in the large-Nc limit. In the asymptotic regime this nonlinear equation is solved analytically. The anomalous dimensions of the leading-twist baryon operators diagonalizing the evolution are computed analytically up to the next-to-leading order of the 1/Nc expansion.Comment: 44 page

Baryon Distribution Amplitudes in QCD

We develop a new theoretical framework for the description of leading twist light-cone baryon distribution amplitudes which is based on integrability of the helicity $\lambda=3/2$ evolution equation to leading logarithmic accuracy. A physical interpretation is that one can identify a new `hidden' quantum number which distinguishes components in the $\lambda=3/2$ distribution amplitudes with different scale dependence. The solution of the corresponding evolution equation is reduced to a simple three-term recurrence relation. The exact analytic solution is found for the component with the lowest anomalous dimension for all moments $N$, and the WKB-type expansion is constructed for other levels, which becomes asymptotically exact at large $N$. Evolution equations for the $\lambda=1/2$ distribution amplitudes (e.g. for the nucleon) are studied as well. We find that the two lowest anomalous dimensions for the $\lambda=1/2$ operators (one for each parity) are separated from the rest of the spectrum by a finite `mass gap'. These special states can be interpreted as scalar diquarks.Comment: 75 pages, LaTeX style, 18 figures embedded with epsf.st