139 research outputs found
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
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
BFKL predictions for inclusive three jet production at the LHC
We define new observables sensitive to BFKL dynamics in the context of
multijet production at the large hadron collider (LHC). We propose the study of
the inclusive production of three jets well separated in rapidity from each
other, with two of them being very forward. We show that the tagging of a third
jet in the central region of rapidity allows for a very strong test of the BFKL
formalism. In particular, we have studied two projections on azimuthal angles
for the differential cross section which allow for the definition of many
different observables whose behavior when varying the and rapidity of the
central jet is a distinct signal of BFKL dynamics. In order to reduce the
theoretical uncertainties and influence of higher order corrections, we propose
the study of ratios of correlation functions of products of cosines of
azimuthal angle differences among the tagged jets.Comment: 11 pages, 2 figure
The quark induced Mueller-Tang jet impact factor at next-to-leading order
We present the NLO corrections for the quark induced forward production of a
jet with an associated rapidity gap. We make use of Lipatov's QCD high energy
effective action to calculate the real emission contributions to the so-called
Mueller-Tang impact factor. We combine them with the previously calculated
virtual corrections and verify ultraviolet and collinear finiteness of the
final result.Comment: 29 pages, many figure
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
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