Quark orbital-angular-momentum distribution in the nucleon

Hoodbhoy, Pervez; Ji, Xiangdong; Wei, Lu

doi:10.1103/physrevd.59.014013

Cited by 86 publications

(98 citation statements)

References 22 publications

(21 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the forward limit, GPDs reproduce the usual PDFs, and thus a description of GPDs can also be built with the help of the experimental data of PDFs [11]. In addition, the moments of GPDs can provide other new information as well, such as the neutron asymmetry [13] and the quark orbital angular momentum [14,15].…”

Section: Introductionmentioning

confidence: 99%

ρ meson unpolarized generalized parton distributions with a light-front constituent quark model

Sun

Dong

2017

Phys. Rev. D

View full text Add to dashboard Cite

We study ρ meson unpolarized generalized parton distributions based on a light-front constituent quark model where the quark-antiquark-meson vertex is constructed under the symmetric loop momentum convention. The form factors and some other low-energy observables of the ρ meson are calculated. Moreover, the contributions to the form factors and generalized parton distributions from the valence and nonvalence regimes are discussed and analyzed in detail. In the forward limit, the usual structure functions are estimated as well. In addition, by evolving the moments of the obtained structure functions to the scale of the lattice calculation, we give the factorization scale of our quark model. It is found that the present phenomenological model is reasonable to describe the general properties of ρ meson.

show abstract

Section: Introductionmentioning

confidence: 99%

ρ meson unpolarized generalized parton distributions with a light-front constituent quark model

Sun

Dong

2017

Phys. Rev. D

View full text Add to dashboard Cite

show abstract

“…The correct treatment of orbital angular momentum is one of the theoretically most important and probably also most controversal problems in hadron spin physics [1][2][3][4][5][6][7][8][9][10][11][12][13]. On the one hand the ususal NLO-fits to deep inelastic data predict a very large gluon spin (of order 1 ) which has to be balanced by a correspondingly large negative orbital angular momentum contribution.…”

Section: Introductionmentioning

confidence: 99%

Numerical solution of the evolution equation for orbital angular momentum of partons in the nucleon

1999

View full text Add to dashboard Cite

The evolution of orbital angular momentum distributions within the radiative parton model is studied. We use different scenarios for the helicity weighted parton distributions and consider a broad range of input distributions for orbital angular momentum. In all cases we are lead to the conclusion that the absolute value of the average orbital angular momentum per parton peaks at relatively large x ≈ 0.1 for perturbatively accessible scales. Furthermore, in all scenarios considered here the average orbital momentum per parton is several times larger for gluons than for quarks which favours gluon initiated reactions to measure orbital angular momentum. The large gluon polarization typically obtained in NLO-fits to DIS data is in each case primarily canceled by the gluon orbital angular momentum.

show abstract

“…A similar expression holds for gluons. The balance between the different flavors is ruled by evolution equations of DGLAP type [46], because the Mellin moments in x do not alter the short-distance behaviour of QCD. In the asymptotic limit Q 2 → ∞ of the IMF, the nucleon spin is shared approximately in equal parts by (anti)quarks and gluons (for n f = 5 flavors).…”

Section: Generalized Parton Distributions (Gpds)mentioning

confidence: 99%

Imaging the proton

Radici

2016

AIP Conference Proceedings

View full text Add to dashboard Cite

Abstract. We illustrate the need and the advantages of a multi-dimensional exploration of the structure of the nucleon, and in general of hadrons. We introduce new appropriate tools like the Transverse Momentum Distributions (TMDs), which enable us to explore in momentum space the dynamics of partons beyond the usual collinear approximation adopted in the QCD analysis of hard processes. We briefly touch upon the possible breaking of universality for a specific category of TMDs; as an example, we describe the Sivers effect as a fundamental test of our understanding of the color force in QCD. We introduce also the Generalized Parton Distributions (GPDs), which give us a multidimensional picture of partons inside hadrons in configuration space. We emphasize the nontrivial relation between TMDs and GPDs, which are not one the Fourier transformed of the other. We describe the possibility of using these tools to address the (orbital) angular momentum of partons, and we highlight the latest results on the long standing problem of the nucleon spin sum rule. We conclude by briefly mentioning exciting developments from upcoming experiments and from projects on a longer time range.

show abstract

Quark orbital-angular-momentum distribution in the nucleon

Cited by 86 publications

References 22 publications

ρ meson unpolarized generalized parton distributions with a light-front constituent quark model

ρ meson unpolarized generalized parton distributions with a light-front constituent quark model

Numerical solution of the evolution equation for orbital angular momentum of partons in the nucleon

Imaging the proton

Contact Info

Product

Resources

About