33 research outputs found
Rapidity evolution of Wilson lines at the next-to-leading order
At high energies particles move very fast so the proper degrees of freedom
for the fast gluons moving along the straight lines are Wilson-line operators -
infinite gauge factors ordered along the line. In the framework of operator
expansion in Wilson lines the energy dependence of the amplitudes is determined
by the rapidity evolution of Wilson lines. We present the next-to-leading order
hierarchy of the evolution equations for Wilson-line operators.Comment: 5 pages and 2 figures, PRD version with typos correcte
High-energy amplitudes in N=4 SYM in the next-to-leading order
The high-energy behavior of the N=4 SYM amplitudes in the Regge limit can be
calculated order by order in perturbation theory using the high-energy operator
expansion in Wilson lines. At large , a typical four-point amplitude is
determined by a single BFKL pomeron. The conformal structure of the four-point
amplitude is fixed in terms of two functions: pomeron intercept and the
coefficient function in front of the pomeron (the product of two residues). The
pomeron intercept is universal while the coefficient function depends on the
correlator in question. The intercept is known in the first two orders in
coupling constant: BFKL intercept and NLO BFKL intercept calculated in Ref. 1.
As an example of using the Wilson-line OPE, we calculate the coefficient
function in front of the pomeron for the correlator of four currents in
the first two orders in perturbation theory.Comment: 10 pages, 3 figure
Next-to-Leading Order Evolution of Color Dipoles
The small-x deep inelastic scattering in the saturation region is governed by the nonlinear evolution of Wilson-line operators. In the leading logarithmic approximation it is given by the Balitsky-Kovchegov equation for the evolution of color dipoles. In the next-to-leading order the Balitsky-Kovchegov equation gets contributions from quark and gluon loops as well as from the tree gluon diagrams with quadratic and cubic nonlinearities. We calculate the gluon contribution to the small-x evolution of Wilson lines (the quark part was obtained earlier)
Regularization of the Light-Cone Gauge Gluon Propagator Singularities Using Sub-Gauge Conditions
Perturbative QCD calculations in the light-cone gauge have long suffered from
the ambiguity associated with the regularization of the poles in the gluon
propagator. In this work we study sub-gauge conditions within the light-cone
gauge corresponding to several known ways of regulating the gluon propagator.
Using the functional integral calculation of the gluon propagator, we rederive
the known sub-gauge conditions for the theta-function gauges and identify the
sub-gauge condition for the principal value (PV) regularization of the gluon
propagator's light-cone poles. The obtained sub-gauge condition for the PV case
is further verified by a sample calculation of the classical Yang-Mills field
of two collinear ultrarelativistic point color charges. Our method does not
allow one to construct a sub-gauge condition corresponding to the well-known
Mandelstam-Leibbrandt prescription for regulating the gluon propagator poles.Comment: 19 pages, 2 figure
Rapidity Evolution of Wilson Lines at the Next-to-Leading Order
At high energies, particles move very fast, so the proper degrees of freedom for the fast gluons moving along the straight lines are Wilson-line operators—infinite gauge factors ordered along the line. In the framework of operator expansion in Wilson lines, the energy dependence of the amplitudes is determined by the rapidity evolution of Wilson lines. We present the next-to-leading order hierarchy of the evolution equations for Wilson-line operators
Classical Gluon Production Amplitude for Nucleus-Nucleus Collisions: First Saturation Correction in the Projectile
We calculate the classical single-gluon production amplitude in
nucleus-nucleus collisions including the first saturation correction in one of
the nuclei (the projectile) while keeping multiple-rescattering (saturation)
corrections to all orders in the other nucleus (the target). In our
approximation only two nucleons interact in the projectile nucleus: the
single-gluon production amplitude we calculate is order-g^3 and is
leading-order in the atomic number of the projectile, while resumming all
order-one saturation corrections in the target nucleus. Our result is the first
step towards obtaining an analytic expression for the first projectile
saturation correction to the gluon production cross section in nucleus-nucleus
collisions.Comment: 37 pages, 24 figure
Conformal Kernel for the Next-to-Leading-Order BFKL equation in = 4 Super Yang-Mills Theory
Using the requirement of Möbius invariance of = 4 super Yang-Mills amplitudes in the Regge limit, we restore the explicit form of the conformal next-to-leading-order Balitsky-Fadin-Kuraev-Lipatov (BFKL) kernel out of the eigenvalues known from the forward next-to-leading-order BFKL result
Photon Impact Factor and \u3csub\u3eT\u3c/sub\u3e Factorization for DIS in the Next-to-Leading Order
The photon impact factor for the Balitsky-Fadin-Kuraev-Lipatov pomeron is calculated in the next-to-leading order approximation using the operator expansion in Wilson lines. The result is represented as a next-to-leading order T-factorization formula for the structure functions of small- deep inelastic scattering