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We comment on the uniqueness of t-evolution$(t=log(Q^2/\Lambda^2))$ of non-singlet structure functions at low x obtained fromDGLAP equations.

High Energy Physics - Phenomenology · Physics 2007-05-23 D K Choudhury , Atri Deshamukhya

The standard analytic solution to the DGLAP equation in Mellin space is improved by resumming the large x divergences. Explicit results are given to next-to-leading order and next-to-leading logarithmic accuracy. Numerically, the…

High Energy Physics - Phenomenology · Physics 2010-03-25 S. Albino , B. A. Kniehl , G. Kramer

We suggest a new procedure for extrapolating the parton distributions from HERA to much higher energies. The procedure suggested consists of two steps. First, we solve the non-linear evolution equation. Second, we introduce a correcting…

High Energy Physics - Phenomenology · Physics 2015-06-25 M. Lublinsky

The diffractive production of open charm in deep-inelastic scattering is studied in the semiclassical approach which has been proposed recently. In this approach, the leading order process contains a charm quark pair and an additional gluon…

High Energy Physics - Phenomenology · Physics 2009-02-20 W. Buchmueller , A. Hebecker , M. F. McDermott

We explore several models of QCD evolution equations simplified by considering only the rapidity dependence of dipole scattering amplitudes, while provisionally neglecting their dependence on transverse coordinates. Our main focus is on the…

High Energy Physics - Phenomenology · Physics 2009-11-11 P. Rembiesa , A. M. Stasto

We numerically analyse the evolution of the flavor non-singlet $g_{1}$ structure function taking into account the all-order resummation of $\alpha_{s} ln^{2}x$ terms which is expected to have much stronger effects than the DGLAP evolution…

High Energy Physics - Phenomenology · Physics 2007-05-23 Yuichiro Kiyo , Jiro Kodaira , Hiroshi Tochimura

This document describes a Fortran 95 package for carrying out DGLAP evolution and other common manipulations of parton distribution functions (PDFs). The PDFs are represented on a grid in x-space so as to avoid limitations on the functional…

High Energy Physics - Phenomenology · Physics 2010-03-25 Gavin P. Salam , Juan Rojo

In this talk I would like to discuss two aspects of charm physics. One is to show that many standard model predictions for rare decay modes (along with $D^0 -\bar{D}^0$ mixing and CP violation) are extremely small thus opening a window for…

High Energy Physics - Phenomenology · Physics 2011-04-15 Sandip Pakvasa

In a previous paper, we have shown that it was possible to use the DGLAP evolution equatio n to constrain the high-$Q^2$ ($Q^2 \ge 10$ GeV$^2$) behaviour of the residues of a high-e nergy Regge model, and we applied the developed method to…

High Energy Physics - Phenomenology · Physics 2014-11-17 G. Soyez

We have studied how parton distributions based on the inclusion of nonlinear scale evolution and constraints from HERA data affect charm production in $pp$ collisions at center-of-mass energies of 5.5, 8.8 and 14 TeV. We find that, while…

High Energy Physics - Phenomenology · Physics 2014-11-17 K. J. Eskola , V. J. Kolhinen , R. Vogt

DGLAP evolution equations may be presented in a form completely analogous to the Boltzmann equation. This provides a natural proof of the positivity of the spin-dependent parton distributions, provided the initial distributions at $Q^2_0$…

High Energy Physics - Phenomenology · Physics 2014-11-17 C. Bourrely , J. Soffer , O. V. Teryaev

We propose a systematic approximation scheme for solving GLAP evolution equations at small Bjorken-$x$. The approximate solutions interpolate smoothly between hard (singular as $x^{-(1+\lambda)}$, $\lambda> 0$) and soft (singular at most as…

High Energy Physics - Phenomenology · Physics 2007-05-23 L. Mankiewicz , A. Saalfeld , T. Weigl

We consider an abstract evolution equation with linear damping, a nonlinear term of Duffing type, and a small forcing term. The abstract problem is inspired by some models for damped oscillations of a beam subject to external loads or…

Analysis of PDEs · Mathematics 2019-05-21 Marina Ghisi , Massimo Gobbino , Alain haraux

A brief overview is presented of recent developments concerning resummed small-x evolution, based upon the renormalization group equation. The non-singlet and singlet structure functions are discussed for both polarized and unpolarized…

High Energy Physics - Phenomenology · Physics 2011-04-15 J. Blümlein , S. Riemersma , A. Vogt

We summarize our recent result for a splitting function for small x evolution which includes resummed small x logarithms deduced from the leading order BFKL equation with the inclusion of running coupling effects. We compare this improved…

High Energy Physics - Phenomenology · Physics 2007-05-23 Guido Altarelli , Richard D. Ball , Stefano Forte

We propose a new evolution equation for the gluon density relevant for the region of small $x_B$. It generalizes the GLR equation and allows deeper penetration in dense parton systems than the GLR equation does. This generalization consists…

High Energy Physics - Phenomenology · Physics 2009-09-25 E. Laenen , E. Levin

We analize the renormalization group equations of supersymmetric QCD with N=1 for the evolution of parton distributions. For this purpose we develope a simple recursive algorithm in x-space to include both regular regions and supersymmetric…

High Energy Physics - Phenomenology · Physics 2014-11-17 Claudio Coriano

We present progress in development of the truncated Mellin moments approach (TMMA). We show our recent results on the generalization of DGLAP evolution equations and discuss some their applications in spin physics.

High Energy Physics - Phenomenology · Physics 2016-02-17 D. Strozik-Kotlorz , S. V. Mikhailov , O. V. Teryaev

We present a novel approach, based entirely on the gravitational potential, for studying the evolution of non-linear cosmological matter perturbations. Starting from the perturbed Einstein equations, we integrate out the non-relativistic…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Ram Brustein , Antonio Riotto

The DGLAP, BFKL, modified DGLAP and modified BFKL equations are constructed in a unified partonic framework. The antishadowing effect in the recombination process is emphasized, which leads to two different small $x$ behaviors of gluon…

High Energy Physics - Phenomenology · Physics 2007-05-23 Wei Zhu , Zhenqi Shen , Jifeng Yang , Jianhong Ruan