Rare fluctuations of the $S$-matrix at NLO in QCD

Abstract

We calculate the rare fluctuations of the $S$-matrix on top of the full next-to-leading order corrections in the center of mass frame. The relevant result in the saturation regime shows that the exponential factor of the $S$-matrix is $\sqrt{2}$ as large as the result which emerges when the rare fluctuation effects are taken into account. We find that the factor of $\sqrt{2}$ change of the exponential factor is induced by the gluon loop corrections which compensate part of rapidity decrease of the $S$-matrix made by quark loops and lead to the rare fluctuations becoming important again. To ensure the relevant results of the $S$-matrix are independent of the frame choice, the rare fluctuations of the $S$-matrix are also derived in a general frame. It is found that all the results are consistent with each other in both frames.

15 pages, 4 figures

References in corpus (10)

• NLO evolution of color dipoles
• Quark contribution to the small-$x$ evolution of color dipole
• Triumvirate of Running Couplings in Small-x Evolution
• Solving The High Energy Evolution Equation Including Running Coupling Corrections
• Resumming double logarithms in the QCD evolution of color dipoles
• Direct numerical solution of the coordinate space Balitsky-Kovchegov equation at next to leading order
• High energy scattering in the saturation regime including running coupling and rare fluctuation effects
• On parton number fluctuations at various stages of the rapidity evolution
• CGC/saturation approach: a new impact-parameter dependent model in the next-to-leading order of perturbative QCD
• Fluctuations of the multiplicity of produced particles in onium-nucleus collisions