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Related papers: A matrix formulation for small-x singlet evolution

200 papers

We show for a first time ever a prototype of a fully exclusive QCD NLO parton shower for the initial state (albeit for a limited set of diagrams). It is based on the rigorous theorems of the collinear factorisation, however the standard…

High Energy Physics - Phenomenology · Physics 2014-11-20 Maciej Skrzypek , Stanislaw Jadach

We have analytically solved the LO pQCD singlet DGLAP equations using Laplace transform techniques. Newly-developed highly accurate numerical inverse Laplace transform algorithms allow us to write fully decoupled solutions for the singlet…

High Energy Physics - Phenomenology · Physics 2015-03-17 Martin M. Block , Loyal Durand , Phuoc Ha , Douglas W. McKay

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…

High Energy Physics - Phenomenology · Physics 2009-10-31 M. Ciafaloni , D. Colferai

We extend our previous results on small-x resummation in the pure Yang--Mills theory to full QCD with nf quark flavours, with a resummed two-by-two matrix of resummed quark and gluon splitting functions. We also construct the corresponding…

High Energy Physics - Phenomenology · Physics 2008-11-26 Guido Altarelli , Richard D. Ball , Stefano Forte

Using the colour dipole picture for photon-nucleus interactions at small $x$ together with the Color Glass Condensate (CGC) effective theory, we demonstrate that the next-to-leading (NLO) order corrections to the cross-section for the…

High Energy Physics - Phenomenology · Physics 2025-05-05 Paul Caucal , Edmond Iancu

We investigate the importance of unitarity corrections to parton evolution in heavy flavor production at the LHC. The gluon distribution is determined with a fit to HERA data applying a unified BFKL-DGLAP approach, in which the non-linear…

High Energy Physics - Phenomenology · Physics 2017-08-23 Krisztian Peters

Guided by considerations of flavour symmetry, we construct a set of exact Standard Model (SM) renormalisation group evolution invariants which link quark masses and mixing parameters. We examine their phenomenological implications and infer…

High Energy Physics - Phenomenology · Physics 2010-12-13 P. F. Harrison , R. Krishnan , W. G. Scott

We construct an anomalous dimension for small x evolution which goes beyond standard fixed order perturbative evolution by including resummed small x logarithms deduced from the leading order BFKL equation with running coupling.…

High Energy Physics - Phenomenology · Physics 2008-11-26 Guido Altarelli , Richard D. Ball , Stefano Forte

We present particular and unique solutions of Dokshitzer-Gribov-Lipatov- Altarelli-Parisi (DGLAP) evolution equations for light sea and valence quark structure functions in leading order (LO). We obtain t evolutions of sea and valence quark…

High Energy Physics - Phenomenology · Physics 2012-09-21 R. Rajkhowa , J. K. Sarma

. We study the evolution of the distribution of eigenvalues of a $N\times N$ matrix subject to a random perturbation drawn from (i) a generalized Gaussian ensemble (ii) a non-Gaussian ensemble with a measure variable under the change of…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Pragya Shukla

We consider a nonlinear evolution equation recently proposed to describe the small-$x$ hadronic physics in the regime of very high gluon density. This is a functional Fokker-Planck equation in terms of a classical random color source, which…

High Energy Physics - Phenomenology · Physics 2009-10-31 Edmond Iancu , Andrei Leonidov , Larry McLerran

Contributions to QCD non-singlet evolution kernels $P(z)$ for the DGLAP equation and $V(x,y)$ for the Brodsky-Lepage evolution equation are calculated for a certain class of diagrams which include renormalon chains. Closed expressions are…

High Energy Physics - Phenomenology · Physics 2014-11-17 S. V. Mikhailov

We incorporate the next-to-leading order (NLO) and the next-to-next-to-leading order (NNLO) effects in the models of the Singlet Structure function F_2^S(x,t) and the gluon distribution G(x,t) using DGLAP equations approximated at small x.…

High Energy Physics - Phenomenology · Physics 2024-11-28 Luxmi Machahari , D. K. Choudhury

We compute the longitudinal proton structure function F_L from the k_T factorization scheme, using the unified DGLAP/BFKL resummation approach at small x for the unintegrated gluon density. The differences between the k_T factorization,…

High Energy Physics - Phenomenology · Physics 2009-11-20 Krzysztof Golec-Biernat , Anna M. Stasto

A computer study is performed to estimate the influence of the small-$k_T$ region in the BFKL evolution equation. We consider the small-x region of the deep inelastic structure function $F_2$ and show that the magnitude of the small-$k_T$…

High Energy Physics - Phenomenology · Physics 2014-11-17 J. Bartels , H. Lotter , M. Vogt

I report on the recent proposal of a generalized small-x equation which, in addition to exact leading and next-to-leading BFKL kernels, incorporates renormalization group constraints in the relevant collinear limits.

High Energy Physics - Phenomenology · Physics 2009-10-31 Marcello Ciafaloni

We analize the use of algorithms based in x-space for the solution of renormalization group equations of DGLAP-type and test their consistency by studying bounds among partons distributions - in our specific case Soffer's inequality and the…

High Energy Physics - Phenomenology · Physics 2014-11-17 Alessandro Cafarella , Claudio Coriano' , Marco Guzzi

An analytical solution of the QCD evolution equations for the singlet and gluon distribution is presented. We decouple DGLAP evolution equations into the initial conditions by using a Laplace transform method at $N^{n}LO$ analysis. The…

High Energy Physics - Phenomenology · Physics 2019-05-13 B. Rezaei , G. R. Boroun

We investigate numerical solution of the Dokshitzer-Gribov-Lipatov-Altarelli- Parisi (DGLAP) Q^2 evolution equation for the transversity distribution Delta_T q or the structure function h_1. The leading-order (LO) and next-to- leading-order…

High Energy Physics - Phenomenology · Physics 2014-11-17 M. Hirai , S. Kumano , M. Miyama

In this paper we derive an integral equation for the evolution of unintegrated (longitudinally) polarized quark and gluon parton distributions. The conventional CCFM framework is extended at small x in order to incorporate the QCD…

High Energy Physics - Phenomenology · Physics 2009-11-07 Jan Kwiecinski , Martin Maul