141 research outputs found
The effective action and the triple Pomeron vertex
We study integrations over light-cone momenta in the gauge invariant
effective action of high energy QCD. A regularization mechanism which allows
for the evaluation of the longitudinal integrations is presented. After a
rederivation of the reggeized gluon and the BFKL-equation from the effective
action, we study the 1-3 and 2-4 reggeized gluon transition vertex of QCD
Reggeon field theory and discuss their connection with the usual triple Pomeron
vertex of perturbative QCD.Comment: Talk given at the 3rd International Hadron Structure '09 Conference,
Tatranska Strba, Slovakia, 30 Aug - 3 Sep 2009; 4 pages, 16 figure
The growth with energy of exclusive and photo-production cross-sections and BFKL evolution
We investigate whether NLO BFKL evolution is capable to describe the energy
dependence of the exclusive photo-production cross-section of vector mesons
and on protons. Our description is based on available NLO
BFKL fits of the proton impact factor in inclusive DIS, which allow us to
construct the necessary scattering amplitude at zero momentum transfer .
Assuming an exponential drop-off with , this result allows us to calculate
the exclusive photoproduction cross-section. Comparing our results with both
HERA data (measured by H1 and ZEUS collaborations in collision) and LHC
data (measured by ALICE, CMS and LHCb collaborations in ultra-peripheral
and collision) we find that our framework provides a very good
description of the energy dependence of the and
photoproduction cross-section, providing therefore further evidence for BFKL
evolution at the LHC. The available fits of the proton impact factor require on
the other hand an adjustment in the overall normalization.Comment: 4 pages, 4 figures; Proceedings of the International Workshop on
Diffraction in High-Energy Physics (DIFFRACTION 2016), September 2 - 8, 2016,
Acireale (Italy
The Mueller-Tang jet impact factor at NLO from the high energy effective action
We report on recent progress in the evaluation of next-to-leading order
observables using Lipatov's QCD high energy effective action. In this
contribution we focus on the determination of the real part of the
next-to-leading order corrections to the Mueller-Tang impact factor which is
the only missing element for a complete NLO BFKL description of quark induced
dijet events with a rapidity gap.Comment: 5 pages, Proceedings of 7th International Workshop on Diffraction in
High Energy Physics (Diffraction 2012
Forward Drell-Yan plus backward jet as a test of BFKL evolution
We study Drell-Yan plus jet events where the gauge boson is produced in the
forward direction of one of the colliding protons and a jet is produced in the
forward direction of the second proton. The resulting large rapidity difference
between the final states then opens up the phase space for BFKL evolution.
First numerical results on partonic level are provided.Comment: 4 pages, 2 figures, proceedings of the XX Workshop on Deep-Inelastic
Scattering and Related Subjects, 26-30 March, University of Bonn (2012
Extension of the Color Glass Condensate Approach to Diffractive Reactions
We present an evolution equation for the Bjorken x dependence of diffractive
dissociation on hadrons and nuclei at high energies. We extend the formulation
of Kovchegov and Levin by relaxing the factorization assumption used there. The
formulation is based on a technique used by Weigert to describe interjet energy
flow. The method can be naturally extended to other exclusive observables
Quark contribution to the gluon Regge trajectory at NLO from the high energy effective action
The two loop (NLO) diagrams with quark content contributing to the gluon
Regge trajectory are computed within the framework of Lipatov's effective
action for QCD, using the regularization procedure for longitudinal
divergencies recently proposed by two of us in
http://arXiv.org/abs/arXiv:1110.6741. Perfect agreement with previous results
in the literature is found, providing a robust check of the regularization
prescription and showing that the high energy effective action is a very useful
computational tool in the quasi-multi-Regge limit.Comment: 12 page, many figure
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