We derive the solution of the NLO BFKL equation by constructing its eigenfunctions perturbatively, using an expansion around the LO BFKL (conformal) eigenfunctions. This method can be used to construct a solution of the BFKL equation with the kernel calculated to an arbitrary order in the coupling constant.
It has been recently found that the heavy quark-antiquark QQbar pair multiplicity, in certain phase space region (QQbar at short distance, soft and with small velocity), satisfies an evolution equation formally similar to the BFKL equation for the high energy scattering amplitude. We find the exact solution of the QQbar-equation and discuss the differences with the BFKL scattering amplitude.
On the basis of a renormalization group analysis of the kernel and of the solutions of the BFKL equation with subleading corrections, we propose and calculate a novel expansion of a properly defined effective eigenvalue function. We argue that in this formulation the collinear properties of the kernel are taken into account to all orders, and that the ensuing next-to-leading truncation provides a much more stable estimate of hard Pomeron and of resummed anomalous dimensions.
The BK equation in the conformal basis is considered and analyzed. It is shown that at high energy a factorization of the coordinate and rapidity dependence should hold. This allows to simplify significantly the from of the equation under discussion. An analytical ansatz for the solution to the BK equation at high energies is proposed and analyzed. This analytical ansatz satisfies the initial condition at low energy and does not depend on both rapidity and the initial condition in the high energy limit. The case of the final rapidity being not too large is discussed and the properties of the transition region between small and large final rapidities have been studied.
Details of the calculation of the non-forward BFKL kernel at next-to-leading order (NLO) are offered. Specifically we show the calculation of the two-gluon production contribution. This contribution was the last missing part of the kernel. Together with the NLO gluon Regge trajectory, the NLO contribution of one-gluon production and the contribution of quark-antiquark production which were found before it defines the kernel completely for any colour state in the $t$-channel, in particular the Pomeron kernel presented recently.
In this paper we encode the perturbative BFKL leading logarithmic resummation, relevant for the Regge limit behavior of QCD scattering amplitudes, in the IR-regulated effective action which satisfies exact functional renormalization group equations. This is obtained using a truncation with a specific infinite set of non local vertices describing the multi-Regge kinematics (MRK). The goal is to use this framework to study, in the high energy limit and at larger transverse distances the transition to a much simpler effective local reggeon field theory, whose critical properties were recently investigated in the same framework. We perform a numerical analysis of the spectrum of the BFKL Pomeron deformed by the introduction of a Wilsonian infrared regulator to understand the properties of the leading poles (states) contributing to the high energy scattering.
Giovanni A. Chirilli
,Yuri V. Kovchegov
.
(2013)
.
"Solution of the NLO BFKL Equation and a Strategy for Solving the All-Order BFKL Equation"
.
Yuri V. Kovchegov
هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا