English
Related papers

Related papers: Analytic Approach to Small-X Structure Functions

200 papers

We discuss how momentum conservation is implemented in perturbative computations based on expansions of anomalous dimensions appropriate at small $x$. We show that for any given choice of $F_2$ coefficient functions there always exists a…

High Energy Physics - Phenomenology · Physics 2009-10-28 R. D. Ball , S. Forte

I investigate the relationship between the gluon distribution obtained using a dipole model fit to low-x data on F_2(x,Q^2) and standard gluons obtained from global fits with the collinear factorization theorem at fixed order. I stress the…

High Energy Physics - Phenomenology · Physics 2014-11-18 R. S. Thorne

We show how perturbation theory may be reorganized to give splitting functions which include order by order convergent sums of all leading logarithms of $x$. This gives a leading twist evolution equation for parton distributions which sums…

High Energy Physics - Phenomenology · Physics 2014-11-17 R. D. Ball , S. Forte

In this short survey article, we showcase a number of non-trivial geometric problems that have recently been resolved by marrying methods from functional calculus and real-variable harmonic analysis. We give a brief description of these…

Differential Geometry · Mathematics 2019-09-18 Lashi Bandara

We study the heavy-quark contributions to the proton structure function F2(x,Q2) at next-to-leading order using compact formulas at small values of Bjorken's x variable. The formulas provide a good agreement with the modern HERA data for…

High Energy Physics - Phenomenology · Physics 2015-05-27 A. Yu. Illarionov , A. V. Kotikov

We present some simple methods to find gluon distribution from analysis of deuteron F_{2} structure function data at moderately low-x. Here we use the leading order(LO) Altarelli -Parisi(AP) evolution equation and New Muon Collaboration…

High Energy Physics - Phenomenology · Physics 2014-11-17 J. K. Sarma , G. A. Ahmed

We calculate the perturbative parts of the structure functions $F_2^c$ and $F_L^c$ for a gluon target having nonzero transverse momentum squared at order $\alpha_s$. The results of the double convolution (with respect to the Bjorken…

High Energy Physics - Phenomenology · Physics 2011-09-13 A. V. Kotikov , A. V. Lipatov , G. Parente , N. P. Zotov

I explicitly calculate the anomalous dimensions and splitting functions governing the Q^2 evolution of the parton densities and structure functions which result from the running coupling BFKL equation at LO, i.e. I perform a resummation in…

High Energy Physics - Phenomenology · Physics 2009-11-07 R. S. Thorne

The resummation of $O(\alpha_s^{l+1} \ln^{2l} x)$ terms in the evolution equation of the singlet part of $g_1(x,Q^2)$ is carried out. The corresponding singlet evolution kernels are calculated explicitely. The leading small-$x$ contribution…

High Energy Physics - Phenomenology · Physics 2009-10-28 J. Blümlein , A. Vogt

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

We examine the effect of using an angular ordered evolution equation for the unintegrated gluon distribution at small x.

High Energy Physics - Phenomenology · Physics 2009-10-30 G. Bottazzi

We review recent HERA data on the structure function F_2 at small x and large Q^2. We show that the salient features of the data are revealed by comparing them to the double asymptotic scaling behaviour which F_2 is predicted to satisfy in…

High Energy Physics - Phenomenology · Physics 2009-10-28 Stefano Forte , Richard D. Ball

The explicit expressions describing the structure function g_1 at arbitrary x and Q^2 are obtained. In the first place, they combine the well-known DGLAP expressions for g_1 with the total resummation of leading logarithms of x, which makes…

High Energy Physics - Phenomenology · Physics 2007-11-30 B. I. Ermolaev , M. Greco , S. I. Troyan

In recent years, Fractal Inspired Models of quark and gluon densities at small x have been proposed. In this paper, we investigate longitudinal structure function F-L (x, Q2) within this approach. We make predictions using the QCD based…

High Energy Physics - Phenomenology · Physics 2014-04-28 Akbari Jahan , D. K. Choudhury

We present all-order expressions for the leading double-logarithmic threshold contributions to the quark-gluon coefficient functions for inclusive Higgs-boson production in the heavy top-quark limit and for Drell-Yan lepton-pair production.…

High Energy Physics - Phenomenology · Physics 2015-06-22 N. A. Lo Presti , A. A. Almasy , A. Vogt

We show that when screening corrections are included $\frac{\partial F_{2}(x,Q^{2})}{\partial ln(Q^{2}/Q_{0}^{2})}$ is consistent with the behaviour that one expects in pQCD. Screening corrections explain the enigma of the Caldwell plot.…

High Energy Physics - Phenomenology · Physics 2007-05-23 E. Gotsman

I investigate what a direct measurement of the longitudinal structure function F_L(x,Q^2) could teach us about the structure of the proton and the best way in which to use perturbative QCD for structure functions. I assume HERA running at a…

High Energy Physics - Phenomenology · Physics 2017-08-23 R. S. Thorne

We recall the origin of angular ordering of soft parton emission in the region of small $x$ and show that this coherent structure can be detected in associated distributions. For structure functions at small $x$ and at fixed transverse…

High Energy Physics - Phenomenology · Physics 2009-10-28 Giuseppe Marchesini

We present an analysis of the heavy quark structure functions from the $k_{t}$ factorization scheme, using unifying the color dipole picture and double asymptotic scaling approaches at small $x$. The gluon distribution is obtained from the…

High Energy Physics - Phenomenology · Physics 2024-03-12 G. R. Boroun

We show that the diffractive structure function is perturbatively calculable in the domain where the diffractive mass is small but still outside the resonance region. In this domain, which can be characterized by Lambda^2/Q^2 << 1-beta <<…

High Energy Physics - Phenomenology · Physics 2009-02-20 A. Hebecker , T. Teubner