English
Related papers

Related papers: Gluon evolution at low $x$ and the longitudinal st…

200 papers

We solve a unified integral equation to obtain the $x, Q_T$ and $Q$ dependence of the gluon distribution of a proton in the small $x$ regime; where $x$ and $Q_T$ are the longitudinal momentum fraction and the transverse momentum of the…

High Energy Physics - Phenomenology · Physics 2014-11-17 J. Kwiecinski , A. D. Martin , P. J. Sutton

I use a direct method to extract the longitudinal structure function in the next-to-leading order approximation with respect to the number of active flavor from the parametrization of parton distributions. The contribution of charm and…

High Energy Physics - Phenomenology · Physics 2021-10-12 G. R. Boroun

Gluon distribution function at small x is computed using the extended McLerran-Venugopalan model. A lipatov like enhancement is seen as well as a non-trivial transverse momentum dependence which is estimated. It is shown that gluon density…

High Energy Physics - Phenomenology · Physics 2007-05-23 Jamal Jalilian-Marian

In this paper, we solved the coupled Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) evolution equations for singlet and gluon structure functions in leading order (LO) at low-x assuming the Regge behaviour of quark and gluon structure…

High Energy Physics - Phenomenology · Physics 2008-10-22 U. Jamil , J. K. Sarma

We show that it is possible to use hard-Pomeron behavior to the gluon distribution and singlet structure function at low $x$. We derive a second-order independent differential equation for the gluon distribution and the singlet structure…

High Energy Physics - Phenomenology · Physics 2014-02-05 B. Rezaei , G. R. Boroun

The behavior of the gluon distribution function and the reduced cross section considered from the proton structure function and its derivatives at low values of $x$. These behaviors studied and compared with the experimental data. These…

High Energy Physics - Phenomenology · Physics 2020-11-17 B. Rezaei , G. R. Boroun

In this paper, the evolutions of longitudinal proton structure function have been obtained at small-$x$ up to next-to-next-to-leading order using a hard Pomeron behavior. In our paper, evolutions of gluonic as well as heavy longitudinal…

High Energy Physics - Phenomenology · Physics 2014-12-05 G. R. Boroun , B. Rezaei , J. K. Sarma

Calculations are presented of the longitudinal structure function $F_L(x, Q^2)$. We use next-to-leading order expressions in QCD $({\cal{O}}(\alpha_s^2))$ plus parton densities determined previously from global fits to data on deep…

High Energy Physics - Phenomenology · Physics 2014-11-17 Edmond L. Berger , Ruibin Meng

The longitudinal structure function in deep inelastic scattering is one of the observables from which the gluon distribution can be unfolded. Consequently, this observable can be used to constrain the QCD dynamics at small $x$. In this work…

High Energy Physics - Phenomenology · Physics 2011-09-13 V. P. Goncalves , M. V. T. Machado

The fragmentation functions of quarks and gluons into photons are studied beyond the Leading Logarithm approximation. We address the nature of the initial conditions of the evolution equation solutions and study problems related to…

High Energy Physics - Phenomenology · Physics 2010-04-06 L. Bourhis , M. Fontannaz , J. Ph. Guillet

We numerically study the effects of high gluon density at small x on the evolution of gluon distribution function in both hadrons and nuclei. Using a newly derived, Wilson renormalization group-based evolution equation which includes n to 1…

High Energy Physics - Phenomenology · Physics 2014-11-17 Jamal Jalilian-Marian , Xin-Nian Wang

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

Using momentum sum rule for evolution equations for Double Parton Distribution Functions (DPDFs) in the leading logarithmic approximation, we find that the double gluon distribution function can be uniquely constrained via the single gluon…

High Energy Physics - Phenomenology · Physics 2016-06-07 Krzysztof Golec-Biernat , Emilia Lewandowska , Mirko Serino , Zachary Snyder , Anna Stasto

We present the gluon distribution functions of pion and kaon in small-$x$ and large-$x$ regions, and compare them with the results obtained from lattice QCD and continuum Schwinger function methods. Whether in the small-$x$ region or the…

High Energy Physics - Phenomenology · Physics 2024-05-28 Chengdong Han , Wei Kou , Rong Wang , Xurong Chen

We present a set of formulas to extract two second-order independent differential equations for the gluon and singlet distribution functions. Our results extend from the LO up to NNLO DGLAP evolution equations with respect to the…

High Energy Physics - Phenomenology · Physics 2014-02-04 G. R. Boroun , B. Rezaei

We extend our previous derivation of an exact expression for the leading-order (LO) gluon distribution function $G(x,Q^2)=xg(x,Q^2)$ from the DGLAP evolution equation for the proton structure function $F_2^{\gamma p}(x,Q^2)$ for deep…

High Energy Physics - Phenomenology · Physics 2009-02-13 Martin M. Block , Loyal Durand

This is a draft describing the calculation of the evolution of the gluon density in $x$ from an initial value $x=x_{0}=0.01$ to smaller values, up to $x=10^{-8}$ in the hard pomeron formalism with a running coupling introduced on the basis…

High Energy Physics - Phenomenology · Physics 2014-11-17 Mikhail Braun , Gian Paolo Vacca

We consider the interaction of the partonic fluctuation of a scalar ``photon'' with an external color field to calculate the leading and next-to-leading order gluon distribution of the proton following the work done by…

High Energy Physics - Phenomenology · Physics 2009-11-10 H. -J. Pirner , A. I. Shoshi , G. Soyez

We present the first experiment-based parameterization of differential gluon structure function, which is called upon in many applications. We compare $\kappa$-factorization and DGLAP approaches and analyze properties of DGSF, with special…

High Energy Physics - Phenomenology · Physics 2007-05-23 I. P. Ivanov , N. N. Nikolaev

We present a method for the analytic solution of small $x$ structure functions. The essential small $x$ logarithms are summed to all orders in the anomalous dimensions and coefficient functions. Although we work at leading logarithmic…

High Energy Physics - Phenomenology · Physics 2010-03-25 J. R. Forshaw R. G. Roberts R. S. Thorne