Applications of Lipatov's high energy effective action to NLO BFKL jet phenomenology

We report on recent progress in the evaluation of next-to-leading order (NLO) observables using Lipatov's QCD high energy effective action. We calculate both real and virtual corrections to the quark induced forward jet vertex at NLO, making use of a new regularization method and a subtraction mechanism. As a new result we determine the real part of the NLO Mueller-Tang impact factor which is the only missing element for a complete NLO BFKL description of dijet events with a rapidity gap.Comment: 4 pages, 29 figures, proceedings of the XX Workshop on Deep-Inelastic Scattering and Related Subjects, 26-30 March, University of Bonn (2012

The next-to-leading order vertex for a forward jet plus a rapidity gap at high energies

We present the results for the calculation of the forward jet vertex associated to a rapidity gap (coupling of a hard pomeron to the jet) in the Balitsky-Fadin-Kuraev-Lipatov (BFKL) formalism at next-to-leading order (NLO). We handle the real emission contributions making use of the high energy effective action proposed by Lipatov, valid for multi-Regge and quasi-multi-Regge kinematics. This result is important since it allows, together with the NLO non-forward gluon Green function, to perform NLO studies of jet production in diffractive events (Mueller-Tang dijets, as a well-known example).Comment: 12 pages, some figure

Brodsky-Lepage-Mackenzie optimal renormalization scale setting for semihard processes

The Balitsky-Fadin-Kuraev-Lipatov (BFKL) approach for the investigation of semihard processes is plagued by large next-to-leading corrections, both in the kernel of the universal BFKL Green's function and in the process-dependent impact factors, as well as by large uncertainties in the renormalization scale setting. All that calls for an optimization procedure of the perturbative series. In this respect, one of the most common methods is the Brodsky-Lepage-Mackenzie (BLM) one, which eliminates the renormalization scale ambiguity by absorbing the nonconformal β0 terms into the running coupling. In this paper, we apply the BLM scale setting procedure directly to the amplitudes (cross sections) of several semihard processes. We show that, due to the presence of β0 terms in the next-to-leading expressions for the impact factors, the optimal renormalization scale is not universal but depends both on the energy and on the type of process in questionD. I. thanks the Dipartimento di Fisica dell’Università della Calabria and the Istituto Nazionale di Fisica Nucleare (INFN), Gruppo collegato di Cosenza for the warm hospitality and financial support. The work of D. I. was also supported in part by the Russian Foundation for Basic Research via Grant No. RFBR-13-02-00695-a. The work of B. M. was supported by the European Commission, European Social Fund and Calabria Region, who disclaim any liability for any use made of the information provided in this paper. B. M. thanks the Sobolev Institute of Mathematics of Novosibirsk for warm hospitality during the preparation of this wor

A study of the diffusion pattern in N=4 SYM at high energies

In the context of evolution nequations and scattering amplitudes in the high energy limit of the N=4 super Yang–Mills theory we investigate in some detail the BFKL gluon Green function at next-to-leading order. In particular, we study its collinear be havi or in term so fan expansion in different angular components. We also perform a Monte Carlo simulation of the different final states contributing to such a Green function and construct the diffusion pattern in to in frared and ultraviolet modes and multiplicity distributions, making emphasis in separating the gluon contributions from those of scalars and gluinos. We find that the combined role of the non-gluonic degree sof freedom is to improve the collinear behavior and reduce the diffusion in to ultraviolet regions while not having any effect ont heaver age multiplicities or diffusion in to the in frared. In terms of growth with energy,the non-zero conformal spin components are mainly driven by the gluon terms in the BFKLkernel. Forze rocon formal spin (Pomeron) the effect the scalar and gluino sectors is to dramatically push the Green function towards higher valuesF.C. thanks the Instituto de Física Teórica UAM/CSIC for the warm hospitality.Weack now ledge partial support from the European Comission under contract LHC PhenoNet (PITN-GA-2010-264564), the Comunidad de Madrid through HEPHACOSS2009/ESP-1473, and MICINN (FPA2010-17747) and Spanish MINECOs Centro de Excelencia Severo Ochoa Programme under grant SEV-2012-0249.TheworkofF.C.was supported by EuropeanCommission, European Social Fund and Calabria Region,that disclaim many lia-bility for the use that can be done of the information provided in this Letter.G.C. thanks the support from the Research Executive Agency(REA)of the European Union under the Grant Agree ment number PIEF-GA-2011-298582 and by MICINN (FPA2011-23778,FPA2007-60323 and CSD2007-00042CPAN

Inclusive production of two rapidity-separated heavy quarks as a probe of BFKL dynamics

The inclusive photoproduction of two heavy quarks, separated by a large rapidity interval, is proposed as a new channel for the manifestation of the Balitsky-Fadin-Kuraev-Lipatov (BFKL) dynamics. The extension to the hadroproduction case is also discussed