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Related papers: Helicity Evolution at Small x: Summary of Recent D…

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We computed the longitudinal proton structure function $F_{L}$, using the nonlinear Dokshitzer-Gribov-Lipatov-Altarelli-parisi (NLDGLAP) evolution equation approach at small $x$. For the gluon distribution, the nonlinear effects are related…

High Energy Physics - Phenomenology · Physics 2014-02-07 G. R. Boroun

We show that the whole range of RHIC data for hadron production in d-Au collisions is compatible with geometric scaling. To establish the scaling violations expected from small-x evolution a larger kinematic range in transverse momentum and…

High Energy Physics - Phenomenology · Physics 2008-06-26 Andre Utermann

Nonlinear evolution equation at small x with impact parameter dependence is analyzed numerically. Saturation scales and the radius of expansion in impact parameter are extracted as functions of rapidity. Running coupling is included in this…

High Energy Physics - Phenomenology · Physics 2015-03-17 Jeffrey Berger , Anna Stasto

Saturation and geometrical scaling (GS) of gluon distributions are a consequence of the non-linear evolution equations of QCD. We argue that in pp GS holds for the inelastic cross-section rather than for the multiplicity distributions. We…

High Energy Physics - Phenomenology · Physics 2016-07-15 Michal Praszalowicz

We develop simple analytic representations of the polarized quark and gluon distributions in the nucleon at low $Q^2$ which incorporate general constraints obtained from the requirements of color coherence of gluon couplings at $x \sim 0$…

High Energy Physics - Phenomenology · Physics 2009-09-25 Stanley J. Brodsky , Matthias Burkardt , Ivan Schmidt

A survey is given of recent developments on the resummed small-$x$ evolution, in a framework based on the renormalization group equation, of non--singlet and singlet structure functions in both unpolarized and polarized deep--inelastic…

High Energy Physics - Phenomenology · Physics 2015-06-25 J. Blümlein , S. Riemersma , A. Vogt

It is shown that the proton "spin crisis'' or "spin puzzle" can be understood by the relativistic effect of quark transversal motions due to the Melosh-Wigner rotation. The quark helicity $\Delta q$ measured in polarized deep inelastic…

High Energy Physics - Phenomenology · Physics 2011-04-15 Bo-Qiang Ma

The corrections of gluon fusion to the DGLAP and BFKL equations are discussed in a united partonic framework. The resulting nonlinear evolution equations are the well-known GLR-MQ-ZRS equation and a new evolution equation. Using the…

High Energy Physics - Phenomenology · Physics 2016-08-08 Wei Zhu , Zhenqi Shen , Jianhong Ruan

Using the recently obtained Pgq splitting function we extend the low x evolution equation for gluons to account for contributions originating from quark-to-gluon splitting. In order to write down a consistent equation we resum virtual…

High Energy Physics - Phenomenology · Physics 2016-12-21 M. Hentschinski , A. Kusina , K. Kutak

The evolution of polarized quark distribution functions is taken into account the gluon emission and absorption, quark pair production and annihilation processes and treated by a statistical method which provides quark distribution…

High Energy Physics - Phenomenology · Physics 2016-09-06 Hai Lin

We extend our recent derivation of the time evolution equations for the energy content of magnetic fields and turbulent motions for incompressible, homogeneous, and isotropic turbulence to include the case of nonvanishing helicity. These…

Cosmology and Nongalactic Astrophysics · Physics 2013-06-14 Andrey Saveliev , Karsten Jedamzik , Guenter Sigl

We calculate the leading-twist helicity-dependent generalized parton distributions (GPDs) of the proton at finite skewness in the Nambu--Jona-Lasinio (NJL) model of quantum chromodynamics (QCD). From these (and previously calculated…

Nuclear Theory · Physics 2021-04-21 Adam Freese , Ian C. Cloët

We compute the helicity-dependent strange quark distribution in the proton in the framework of chiral effective theory. Starting from the most general chiral SU(3) Lagrangian that respects Lorentz and gauge invariance, we derive the…

High Energy Physics - Phenomenology · Physics 2021-01-01 X. G. Wang , Chueng-Ryong Ji , W. Melnitchouk , Y. Salamu , A. W. Thomas , P. Wang

The $F_{2}$ structure functions of the inelastic lepton-hadron scattering is calculated in the case of non-zero intermediate gluon-quarks self-energy $M_{gq}^{2}$ and quasielastic limit. It is shown that in the quasielastic limit the…

High Energy Physics - Phenomenology · Physics 2007-05-23 Ya. D. Krivenko-Emetov

In this paper the spin-dependent singlet and nonsinglet structure functions have been obtained by solving Dokshitzer-Gribov-Lipatov-Altarelli-Parisi evolution equations in leading order in the small x limit. Here we have used Taylor series…

High Energy Physics - Phenomenology · Physics 2010-02-04 R. Rajkhowa

We present the numerical solution of the leading order QCD evolution equation for the orbital angular momentum distributions of quarks and gluons and discuss its implications for the nucleon spin sum rule. We observe that at small-$x$, the…

High Energy Physics - Phenomenology · Physics 2018-04-11 Yoshitaka Hatta , Dong-Jing Yang

We study the evolution of the small $x$ gluon transverse momentum dependent(TMD) distribution in the dilute limit. The calculation has been carried out in the Ji-Ma-Yuan scheme using a simple quark target model. As expected, we find that…

High Energy Physics - Phenomenology · Physics 2016-07-20 Jian Zhou

We consider a system of evolution equations for quark and gluon structure functions satisfying the leading-logarithmic behaviour due to both QCD collinear $ \left(LLQ^2 \right) $ and infrared $ (LL1/x) $ singularities. We show that these…

High Energy Physics - Phenomenology · Physics 2008-11-26 R. Peschanski , S. Wallon

We study the small-$x$ evolution equation for the gluon generalized parton distribution (GPD) $E_g$ of the nucleon. It is shown that $E_g$ at vanishing skewness exhibits the Regge behavior identical to the BFKL Pomeron, despite its…

High Energy Physics - Phenomenology · Physics 2022-12-22 Yoshitaka Hatta , Jian Zhou

We calculate the helicity and chirality effects experienced by a spin-1/2 particle subjected to classical electromagnetic and gravitational fields. The helicity evolution is then determined in the non-relativistic, relativistic, and…

High Energy Physics - Phenomenology · Physics 2015-06-25 Dinesh Singh , Nader Mobed , Giorgio Papini