2,052 research outputs found

### Instanton-induced production of QCD jets

We consider the instanton contributions for the production of a gluon jet
with large transverse momentum in QCD. We find that Mueller's corrections
corresponding to the rescattering of hard quanta are likely to remove
contributions of large instantons, making this cross section well defined. This
observation generalizes the previous discussion of instanton effects in the
deep inelastic scattering and suggests that all hard processes in the QCD
receive hard non-perturbative corrections from instantons of small size, of
order $\rho\sim 1/(Q\alpha_s)$.Comment: LATEX, 7 pages, DESY 94-17

### Photon impact factor in the next-to-leading order

An analytic coordinate-space expression for the next-to-leading order photon
impact factor for small-$x$ deep inelastic scattering is calculated using the
operator expansion in Wilson lines.Comment: 5 pages, 3 figure

### Photon impact factor and $k_T$-factorization for DIS in the next-to-leading order

The photon impact factor for the BFKL pomeron is calculated in the
next-to-leading order (NLO) approximation using the operator expansion in
Wilson lines. The result is represented as a NLO $k_T$-factorization formula
for the structure functions of small-$x$ deep inelastic scattering.Comment: 13 pages, 4 figures, typos corrected. arXiv admin note: substantial
text overlap with arXiv:1009.472

### Instanton-induced production of jets with large transverse momentum in QCD

We consider the instanton-induced cross section for production of a gluon jet
with large transverse momentum in QCD and point out that Mueller's corrections
corresponding to the rescattering of hard quanta are likely to remove
contributions of large instantons, making this cross section well defined. Some
speculations about possible phenomenological signatures are presented.Comment: LATEX, requires espcrc2.sty file, appended at the end. (Invited talk
presented by V. Braun at the conference ``QCD-94'', Montpellier, France, July
7 -13, 1994), MPI-PhT/94-5

### NLO evolution of color dipoles

The small-$x$ deep inelastic scattering in the saturation region is governed
by the non-linear evolution of Wilson-line operators. In the leading
logarithmic approximation it is given by the BK equation for the evolution of
color dipoles. In the next-to-leading order the BK 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
small-x evolution of Wilson lines (the quark part was obtained earlier).Comment: 43 pages, 12 figure

### Factorization and Effective Action for High-Energy Scattering in QCD

I demonstrate that the amplitude of the high-energy scattering can be
factorized in a convolution of the contributions due to fast and slow fields.
The fast and slow fields interact by means of Wilson-line operators -- infinite
gauge factors ordered along the straight line. The resulting factorization
formula gives a starting point for a new approach to the effective action for
high-energy scattering.Comment: Talk presented at the workshop "Continuous Advances in QCD",
(Minneapolis), April 1998. 15 pages, 3 eps figures, Latex using sprocl.sty
and psfig.te

### Factorization for high-energy scattering

I demonstrate that the amplitude of the high-energy scattering can be
factorized in a product of two independent functional integrals over "fast" and
"slow" fields which interact by means of Wilson-line operators -- gauge factors
ordered along the straight lines.Comment: 4 pages, Latex, 1 postscript figure, to appear in PR

### Rapidity factorization and evolution of gluon TMDs

I discuss how the rapidity evolution of gluon transverse momentum dependent
distribution changes from nonlinear evolution at small $x\ll 1$ to linear
evolution at moderate $x\sim 1$.Comment: 10 pages, contribution to Proceedings of QCD Evolution Workshop 201

### Gluon Distributions and Color Charge Correlations in a Saturated Light-cone Wavefunction

We describe the light-cone wavefunction in the saturation regime in terms of
the density of gluons per unit of transverse phase space, the occupation
number, and in terms of the color charge correlator. The simple McLerran-
Venugopalan model gives what are claimed to be general results for the phase
space gluon density, but it does not well describe the general case for the
charge correlator. We derive the general momentum dependence and rapidity
dependence of the color charge correlator which exhibits strong color
shielding. A simplel physical picture which leads to these general results is
described.Comment: 17 pages, Latex, 7 figure

- …