http://cds.cern.ch/record/326993/files/9705477.pdf

Quantum chromodynamics and other field theories on the light cone

Conformal properties of four-gluon planar amplitudes and Wilson loops

MHV amplitudes in N=4 super Yang-Mills and Wilson loops

On planar gluon amplitudes/Wilson loops duality

Conformal Ward identities for Wilson loops and a test of the duality with gluon amplitudes

High-energy scattering in QCD and cross singularities of Wilson loops

Gauge invariance and anomalous dimensions of a light-cone Wilson loop in light-like axial gauge

We consider elastic quark-quark scattering at high energy and fixed transferred momentum. Performing factorization of soft gluon exchanges into Wilson line expectation value we find that there is one-to-one correspondence between high energy asymptotics in QCD and renormalization properties of the so called cross singularities of Wilson lines. Using this relation we show that the asymptotic behavior of the quark-quark scattering amplitude is controlled by a $2\times 2$ matrix of the cross anomalous dimensions. We evaluate the matrix of cross anomalous dimension to two-loop order and study the properties of the obtained expressions to higher loop order.

High energy scattering in QCD and cross singularities of Wilson loops

Complete two-loop calculation of a dimensionally regularized Wilson loop with light-like segments is performed in the light-like axial gauge with the Mandelstam-Leibbrandt prescription for the gluon propagator. We find an expression which {\it exactly} coincides with the one previously obtained for the same Wilson loop in covariant Feynman gauge. The renormalization of Wilson loop is performed in the $\MS-$scheme using a general procedure tailored to the light-like axial gauge. We find that the renormalized Wilson loop obeys a renormalization group equation with the same anomalous dimensions as in covariant gauges. Physical implications of our result for investigation of infrared asymptotics of perturbative QCD are pointed out.

I.A. Korchemskaya

Papers

High-energy scattering in QCD and cross singularities of Wilson loops

Gauge invariance and anomalous dimensions of a light-cone Wilson loop in light-like axial gauge

High energy scattering in QCD and cross singularities of Wilson loops

Gauge Invariance and Anomalous Dimensions of a Light-Cone Wilson Loop in Light-Like Axial Gauge