NLO jet production in k_T factorization

We discuss the inclusive production of jets in the central region of rapidity in the context of k_T-factorization at next-to-leading order (NLO). Calculations are performed in the Regge limit making use of the NLO BFKL results. We introduce a jet cone definition and carry out a proper phase--space separation into multi-Regge and quasi-multi-Regge kinematic regions. We discuss two situations: scattering of highly virtual photons, which requires a symmetric energy scale to separate impact factors from the gluon Green's function, and hadron-hadron collisions, where a non-symmetric scale choice is needed.Comment: 7 pages, 1 figure, prepared for the 12th International Conference on Elastic and Diffractive Scattering, DESY, Hamburg, 21-25 May 200

Pomeron Odderon interference in production of pi+ pi- pairs at LHC

We discuss the production of two pion pairs in photon collisions at high energies as it can take place in ultraperipheral collisions at hadron colliders such as the LHC. We calculate the according matrix elements in kT factorization and discuss the possibility to reveal the existence of the perturbative Odderon by charge asymmetries.Comment: 5 pages, 5 figures, to be published in the proceedings of the conference DIS 2009, Madrid, April 200

A complete NLL BFKL calculation of Mueller Navelet jets at LHC

For the first time, a next-to-leading BFKL study of the cross section and azimuthal decorrellation of Mueller Navelet jets is performed, i.e. including next-to-leading corrections to the Green's function as well as next-to-leading corrections to the Mueller Navelet vertices. The obtained results for standard observables proposed for studies of Mueller Navelet jets show that both sources of corrections are of equal and big importance for final magnitude and final behavior of observables, in particular for the LHC kinematics investigated here in detail. The astonishing conclusion of our analysis is that the observables obtained within the complete next-lo-leading order BFKL framework of the present paper are quite similar to the same observables obtained within next-to-leading logarithm DGLAP type treatment. This fact sheds doubts on general belief that the studies of Mueller Navelet jets at the LHC will lead to clear discrimination between the BFKL and the DGLAP dynamics.Comment: 5 pages, 2 figures, to appear in the proceedings of 18th International Workshop on Deep-Inelastic Scattering and Related Subjects (DIS 2010), Florence, Italy, 19-23 Apr 201

First complete NLL BFKL calculation of Mueller Navelet jets at LHC

For the first time, a next-to-leading BFKL study of the cross section and azimuthal decorrellation of Mueller Navelet jets is performed, i.e. including next-to-leading corrections to the Green's function as well as next-to-leading corrections to the Mueller Navelet vertices. The obtained results for standard observables proposed for studies of Mueller Navelet jets show that both sources of corrections are of equal and big importance for final magnitude and final behavior of observables, in particular for the LHC kinematics investigated here in detail. The astonishing conclusion of our analysis is that the observables obtained within the complete next-lo-leading order BFKL framework of the present paper are quite similar to the same observables obtained within next-to-leading logarithm DGLAP type treatment. The only noticeable difference is the ratio the azimuthal angular moments / which still differs in both treatments.Comment: 5 pages, 1 figure, to appear in the proceedings of 35th International Conference on High Energy Physics, (ICHEP 2010), Paris, France, July 22-28, 201

Pomeron-Odderon interference in production of pi^ + pi^- pairs in ultraperipheral collisions

In this contribution we discuss the production of two pion pairs in high energy photon collisions as they can be produced in ultraperipheral collisions at hadron colliders such as the Tevatron, RHIC or LHC. We find that charge asymmetries may reveal the existence of the perturbative Odderon.Comment: 5 pages, 3 figures; To appear in the proceedings of Diffraction 2008: International Workshop on Diffraction in High-Energy Physics, La Londe-les-Maures, France, September 9-14, 200

Off-Shell Scattering Amplitudes for WW Scattering and the Role of the Photon Pole

We derive analytic expressions for high energy $2 \to 2$ off-shell scattering amplitudes of weak vector bosons. They are obtained from six fermion final states in processes of the type $e^+ e^- \to \bar\nu_e + (WW) + \nu_e \to \bar\nu_e + (l\nu)(l\nu) + \nu_e$. As an application we reconsider the unitarity bounds on the Higgs mass. Particular attention is given to the role of the photon exchange which has not been considered in earlier investigations; we find that the photon weakens the bound of the Higgs mass.Comment: 16 pages, 8 figure

Hard Pomeron-Odderon interference effects in the production of pi^+pi^- pairs in high energy gamma-gamma collisions at the LHC

We estimate the production of two meson pairs in high energy photon photon collisions produced in ultraperipheral collisions at LHC. We show that the study of charge asymmetries may reveal the existence of the perturbative Odderon and discuss the concrete event rates expected at the LHC. Sizable rates and asymmetries are expected in the case of proton-proton collisions and medium values of gamma-gamma energies \sqrt{s_{\gamma \gamma}} \approx 20GeV. Proton-proton collisions will benefit from a high rate due to a large effective gamma-gamma luminosity and ion-ion collisions with a somewhat lower rate from the possibility to trigger on ultraperipheral collisions and a reduced background from strong interactions.Comment: 10 pages, 6 figure

The first complete NLL BFKL study of Mueller Navelet jets at LHC

We report on the first next-to-leading BFKL study of the cross section and azimuthal decorrellation of Mueller Navelet jets. This includes next-to-leading corrections to the Green's function as well as next-to-leading corrections to the Mueller Navelet vertices. The obtained results for standard observables proposed for studies of Mueller Navelet jets show that both sources of corrections are of equal and big importance for final magnitude and final behavior of observables, in particular for the LHC kinematics investigated here in detail. The astonishing conclusion of our analysis is that the observables obtained within the complete next-lo-leading order BFKL framework of the present contribution are quite similar to the same observables obtained within next-to-leading logarithm DGLAP type treatment. The only noticeable difference is the ratio the azimuthal angular moments / which still differs in both treatments.Comment: 4 pages, 1 figure, To be published in the proceedings of the 2011 Europhysics Conference on High Energy Physics-HEP 2011, July 21-27, 2011 Grenoble, Rhone-Alpes, Franc