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Related papers: Renormalization Group Improved Small-x Equation

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We show how it is possible to rewrite the BFKL equation for the unintegrated gluon distribution, in terms of integrated gluons, similar to that used in DGLAP. We add to our equation the next-to-leading log terms which provide exact…

High Energy Physics - Phenomenology · Physics 2015-06-19 E. G. de Oliveira , A. D. Martin , M. G. Ryskin

On the basis of previous work by Fadin, Lipatov, and collaborators, and of our group, we extract the "irreducible" part of the next-to-leading (NL) BFKL kernel, we compute its (IR finite) eigenvalue function, and we discuss its implications…

High Energy Physics - Phenomenology · Physics 2009-10-30 G. Camici , M. Ciafaloni

In this lecture the next-to-leading order (NLO) corrections to the QCD Pomeron intercept obtained from the Balitsky-Fadin-Kuraev-Lipatov (BFKL) equation are discussed. It is shown that the BFKL Pomeron intercept when evaluated in…

High Energy Physics - Phenomenology · Physics 2007-05-23 V. S. Fadin , V. T. Kim , L. N. Lipatov , G. B. Pivovarov

The higher-order perturbative corrections, beyond leading logarithmic accuracy, to the BFKL evolution in QCD at high energy are well known to suffer from a severe lack-of-convergence problem, due to radiative corrections enhanced by double…

High Energy Physics - Phenomenology · Physics 2015-06-23 E. Iancu , J. D. Madrigal , A. H. Mueller , G. Soyez , D. N. Triantafyllopoulos

We perform analysis of the small x non-linear evolution equation formulated in momentum space supplemented by higher order terms. The equation is defined in wide range of transverse momentum and longitudinal momentum fraction extending…

High Energy Physics - Phenomenology · Physics 2025-06-03 Krzysztof Kutak , Wanchen Li , Anna Stasto , Robert Straka

We present a simple proof of the all-order exponentiation of soft logarithmic corrections to hard processes in perturbative QCD. Our argument is based on proving that all large logs in the soft limit can be expressed in terms of a single…

High Energy Physics - Phenomenology · Physics 2010-04-05 Stefano Forte , Giovanni Ridolfi

We summarize recent progress in the resummation of perturbative evolution at small x. We show that the problem of incorporating BFKL small x logs in GLAP evolution is now completely solved, and that the main effect of small x resummation is…

High Energy Physics - Phenomenology · Physics 2017-08-23 Stefano Forte , Guido Altarelli , Richard D. Ball

We study the anomalous dimensions and coefficient functions generated by the BFKL equation in 4+2 epsilon dimensions, by investigating both running coupling effects, and the inclusion of the full next-to-leading kernel. After generalising…

High Energy Physics - Phenomenology · Physics 2009-11-11 M. Ciafaloni , D. Colferai

The amplitude for 4 interacting reggeized gluons is studied in the high-colour limit. The leading order amplitude is explicitly shown to reduce to a pair of reggeons, i.e to a single BFKL pomeron. The next-to-leading order diffractive…

High Energy Physics - Phenomenology · Physics 2011-09-13 M. Braun

The BFKL and the unified angular-ordered equations are solved to determine the gluon distribution at small $x$. The impact of kinematic constraints is investigated. Predictions are made for observables sensitive to the gluon at small $x$.…

High Energy Physics - Phenomenology · Physics 2009-10-28 J. Kwiecinski , A. D. Martin , P. J. Sutton

Hard scattering processes involving hadrons at small $x$ are described by a $k_T$-factorization formula driven by a BFKL gluon. We explore the equivalence of this description to a collinear-factorization approach in which the anomalous…

High Energy Physics - Phenomenology · Physics 2016-09-01 J. Kwiecinski , A. D. Martin

In the present work we carry out a systematic study of the renormalization properties of the integral equation that determines the momentum evolution of the effective gluon mass. A detailed, all-order analysis of the complete kernel…

High Energy Physics - Phenomenology · Physics 2014-04-23 A. C. Aguilar , D. Binosi , J. Papavassiliou

We derive and solve the renormalisation-group (RG) equation of the shape function $g_{17}(\omega,\omega_1;\mu)$, which appears at subleading power in the factorization of the inclusive decays $\bar{B} \to X_s \gamma$ and $\bar B \to X_s…

High Energy Physics - Phenomenology · Physics 2025-04-15 Riccardo Bartocci , Philipp Böer , Tobias Hurth

We investigate the effect of the resummation of collinear double logarithms in the BFKL gluon Green function using the Monte Carlo event generator BFKLex. The resummed collinear terms in transverse momentum space were calculated in Ref. [1]…

High Energy Physics - Phenomenology · Physics 2016-04-13 G. Chachamis , A. Sabio Vera

We perform the renormalization group improved collinear resummation of the photon-gluon impact factors. We construct the resummed cross section for virtual photon-photon ($\gamma^*\gamma^*$) scattering which incorporates the impact factors…

High Energy Physics - Phenomenology · Physics 2023-11-14 Dimitri Colferai , Wanchen Li , Anna M. Stasto

I discuss radiative corrections to the BFKL equation for high energy cross sections in perturbative QCD. Due to the gluon Reggeization in the next-to-leading $\ln s$ approximation, the form of the BFKL equation remains unchanged and the…

High Energy Physics - Phenomenology · Physics 2007-05-23 V. S. Fadin

We propose a matrix evolution equation in (x,kt)-space for flavour singlet, unintegrated quark and gluon densities, which generalizes DGLAP and BFKL equations in the relevant limits. The matrix evolution kernel is constructed so as to…

High Energy Physics - Phenomenology · Physics 2010-03-25 M. Ciafaloni , D. Colferai , G. P. Salam , A. M. Stasto

We review the parton model and the Regge approach to the QCD description of the deep-inelastic $ep$ scattering at the small Bjorken variable $x$ and demonstrate their relation with the DGLAP and BFKL evolution equations. It is shown, that…

High Energy Physics - Phenomenology · Physics 2014-11-17 L. N. Lipatov

It has been observed recently that a consistent LO BFKL gluon evolution leads to a steep growth of F_2(x,Q^2) for x -> 0 almost independently of Q^2. We show that current data from the DESY HERA collider are precise enough to finally rule…

High Energy Physics - Phenomenology · Physics 2014-11-17 I. Bojak , M. Ernst

We test the performance of a RG-improved kernel in the determination of the amplitude of a physical process, the electroproduction of two light vector mesons,in the BFKL approach at the next-to-leading approximation (NLA). We find that a…

High Energy Physics - Phenomenology · Physics 2008-12-19 Francesco Caporale , Alessandro Papa , Agustin Sabio Vera