Departamento de Gravitación y Teoría de Campos

                          Seminarios 2013

  

                          Instituto de Ciencias Nucleares, UNAM
[ ICN-UNAM]

Jueves 5 de diciembre, a las 17:00 hrs en la Sala de Seminarios del ICN

Martin Hentschinski (Brookhaven National Laboratory)

Reggeization of the gluon and Lipatov's high energy effective action

QCD scattering amplitudes reveal a remarkable simple structure in the Regge limit where the center of mass energy s is taken to infinity. In this regime, a new effective degree of freedom emerges, called the reggeized gluon, which governs the t-channel of such amplitudes. Its propagator is modified by a multiplicative factor s^omega(t), with omega(t) the Regge trajectory of gluon; its coupling to external particles takes on the other hand place through a set of effective vertices. While most prominent in QCD, reggeization is present in many other field theories, such as N=4 SYM, Einstein-Hilbert gravity or QED. In this talk we talk discuss the high energy limit of QCD scattering amplitudes from a new perspective, using Lipatov's high energy effective action. Originally proposed in 1995, it was only until recent that its use for the evaluation of higher order calculation was understood. We give a short introduction to this effective action and present recent results, including a re-derivation of the 2-loop gluon Regge trajectory.