Lorentz Invariance Relations and Wandzura–wilczek Approximation

Teckentrup, T.; Metz, Andreas; Schweitzer, P.

doi:10.1142/s0217732309001169

Cited by 10 publications

(19 citation statements)

References 75 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Certain relations among TMDs must be valid in any quark model of the nucleon lacking gluon degrees of freedom [100]. In such "no-gluon models" the absence of the Wilson-link implies that in the general Lorentz-decomposition of the unintegrated quark-correlator certain amplitudes do not appear, namely the B i -amplitudes (i = 1, 2, .…”

Section: A Relations Valid In All Quark Modelsmentioning

confidence: 99%

“…These so-called "Lorentz-invariance relations" (LIRs) are not valid in models with gauge field degrees of freedom [95] and in QCD [96]. The applications of LIRs in phenomenology were discussed in [99,100]. There it was also shown, by exploring QCD equations of motion, that some LIRs hold in an approximation consisting of the neglect of quark-gluon-quark-correlator and current quark mass terms.…”

Section: A Relations Valid In All Quark Modelsmentioning

confidence: 99%

“…Whether such an approximation is is justified in nature is, of course, a different question. For discussions of specific cases see [98][99][100][101][109][110][111][112][113]. For quark model calculations, the practical application of the relations (34)(35)(36)(37)(38) is immediate: they provide a valuable cross check for the numerical results.…”

Section: A Relations Valid In All Quark Modelsmentioning

confidence: 99%

“…In Sec. V we present and discuss the numerical results, using them, among others, for 'testing' the Gaussian Ansatz or Wandzura-Wilczek-type approximations [98][99][100][101]. Finally, in Sec.…”

Section: Introductionmentioning

confidence: 98%

“…Such relations, especially when supported by several models, could be helpful -at least for qualitative interpretations of first data. Furthermore, model results allow to test assumptions made in literature, such as the Gaussian Ansatz for transverse momentum distributions or certain approximations [95][96][97][98][99][100][101].…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Transverse momentum dependent distribution functions in the bag model

et al. 2010

Self Cite

View full text Add to dashboard Cite

Leading and subleading twist transverse momentum dependent parton distribution functions (TMDs) are studied in a quark model framework provided by the bag model. A complete set of relations among different TMDs is derived, and the question is discussed how model-(in)dependent such relations are. A connection of the pretzelosity distribution and quark orbital angular momentum is derived. Numerical results are presented, and applications for phenomenology discussed. In particular, it is shown that in the valence-x region the bag model supports a Gaussian Ansatz for the transverse momentum dependence of TMDs.

show abstract

Section: A Relations Valid In All Quark Modelsmentioning

confidence: 99%

Section: A Relations Valid In All Quark Modelsmentioning

confidence: 99%

Section: A Relations Valid In All Quark Modelsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Transverse momentum dependent distribution functions in the bag model

et al. 2010

Self Cite

View full text Add to dashboard Cite

show abstract

Unpolarized transverse momentum dependent parton distribution functions beyond leading twist in quark models

Lorcé

Pasquini

Schweitzer

2015

J. High Energ. Phys.

Self Cite

View full text Add to dashboard Cite

Higher-twist transverse momentum dependent parton distribution functions (TMDs) are a valuable probe of the quark-gluon dynamics in the nucleon, and play a vital role for the explanation of sizable azimuthal asymmetries in hadron production from unpolarized and polarized deep-inelastic lepton-nucleon scattering observed in experiments at CERN, DESY and Jefferson Lab. The associated observables are challenging to interpret, and still await a complete theoretical explanation, which makes guidance from models valuable. In this work we establish the formalism to describe unpolarized higher-twist TMDs in the light-front framework based on a Fock-space expansion of the nucleon state in terms of free on-shell parton states. We derive general expressions and present numerical results in a practical realization of this picture provided by the light-front constituent quark model. We review several other popular quark model approaches including free quark ensemble, bag, spectator and chiral quark-soliton model. We discuss how higher-twist TMDs are described in these models, and obtain results for several TMDs not discussed previously in literature. This study contributes to the understanding of non-perturbative properties of subleading twist TMDs. The results from the light-front constituent quark model are also compared to available phenomenological information, showing a satisfactory agreement.

show abstract

Semi-inclusive deep-inelastic scattering in Wandzura-Wilczek-type approximation

Bastami

Avakian

Efremov

et al. 2019

J. High Energ. Phys.

Self Cite

View full text Add to dashboard Cite

We present the complete cross-section for the production of unpolarized hadrons in semi-inclusive deep-inelastic scattering up to power-suppressed O(1/Q 2) terms in the Wandzura-Wilczek-type approximation, which consists in systematically assuming thatqgq-terms are much smaller thanqq-correlators. We compute all twist-2 and twist-3 structure functions and the corresponding asymmetries, and discuss the applicability of the Wandzura-Wilczek-type approximations on the basis of available data. We make predictions that can be tested by data from COMPASS, HERMES, Jefferson Lab, and the future Electron-Ion Collider. The results of this paper can be readily used for phenomenology and for event generators, and will help to improve the description of semi-inclusive deep-inelastic processes in terms of transverse momentum dependent parton distribution functions and fragmentation functions beyond the leading twist.

show abstract

Lorentz Invariance Relations and Wandzura–wilczek Approximation

Cited by 10 publications

References 75 publications

Transverse momentum dependent distribution functions in the bag model

Transverse momentum dependent distribution functions in the bag model

Unpolarized transverse momentum dependent parton distribution functions beyond leading twist in quark models

Semi-inclusive deep-inelastic scattering in Wandzura-Wilczek-type approximation

Contact Info

Product

Resources

About