From Bethe–Salpeter Wave functions to Generalised Parton Distributions

We determine the leading Fock state light front wave functions (LFWFs) of the pion and kaon via light front projections of the covariant Bethe-Salpeter wave function. Using these LFWFs we study the multi-dimensional images of the valence quarks in the pion and kaon that are provided by their generalized parton distribution functions (GPDs) and transverse momentum dependent parton distribution functions (TMDs). Moments of the GPDs are taken to obtain the electromagnetic and gravitational form factors of the pion and kaon, and comparisons to available experimental and lattice data are made. Highlights from this study include predictions that the mean-squared impact parameter for the quarks in the pion and kaon are: b 2 T π u = 0.11 fm 2 , b 2 T K s = 0.08 fm 2 , and b 2 T K u = 0.13 fm 2 , and therefore the s quark in the kaon is much closer to the center of transverse momentum than the u quark. From the electromagnetic and gravitational form factors we find that the light-cone energy radii are about 60% smaller than the light-cone charge radii for each quark sector in the pion and kaon. A quantitative measure of the importance of the leading Fock state is obtained via comparison with a full DSE calculation (containing an infinite tower of Fock states) for the pion form factor.

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“…where k ± T = k 1 ± ik 2 . The LFWFs are obtained from the Bethe-Salpeter wave function via the light front projections [33,38]…”

Section: Pion and Kaon Light Front Wave Functionsmentioning

confidence: 99%

Spatial and momentum imaging of the pion and kaon

et al. 2020

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“…A rigorous evaluation of the PDA certainly requires the computation of L 0 using propagators and amplitudes computed within a QCD-connected, symmetry preserving framework. However, multiple example have highlighted the fact that, the use of algebraic models based on Perturbative Integral Representation (PTIR) reveals itself already insightful [7,[32][33][34][35]39]. We will therefore proceed with developing such a model for the nucleon Faddeev Amplitude.…”

Section: Generalitiesmentioning

confidence: 99%

“…It allows us to write Bethe-Salpeter and Faddeev amplitudes in terms of a known momentum-dependent kernel and a momentumindependent Nakanishi weight function. Interestingly, PTIR is proved to be valid at all order of perturbation theory, and has already been used successfully in the meson sector to compute PDAs and beyond, Parton Distribution Functions (PDFs) and Generalised Parton Distributions (GPDs) (see [5,[28][29][30][31][32][33][34][35][36][37][38]).…”

Section: Introductionmentioning

confidence: 99%

Nucleon Parton Distribution Amplitude: A Scalar Diquark Picture

Mezrag¹,

Segovia²,

Ding³

et al. 2020

Recent Progress in Few-Body Physics

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We report progress on the development of Perturbative Integral Representation Ansätze to compute the nucleon Faddeev Wave function, using an explicit quark-diquark picture. Our formalism is able to handle non-pointlike diquark and to mimic the strong, dynamical correlations observed when solving the Faddeev Equation. We then project the wave function in order to compute the leading-twist Parton Distribution Amplitude.

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“…Refs. [9,16]. The blue solid curves display the numerical results while the red dashed ones show the results algebraically derived in that case.…”

Section: Figure 1: Comparison Between Algebraic and Numerical Resultsmentioning

confidence: 93%

Phenomenology with the PARTONS software of Generalized Parton Distribution models built from Light-Front Wave-functions

Chouika¹

2018

Proceedings of XXVI International Workshop on Deep-Inelastic Scattering and Related Subjects — PoS(DIS2018)

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We present a procedure aiming at extending to the full kinematic domain a Generalized Parton Distribution obtained from a finite order truncation in Fock space. This method allows to fulfill both polynomiality and positivity at the same time and can be applied to any given models of Light-front wave-functions. In particular, we illustrate this on a three-body truncated wavefunction of the chiral quark soliton model and show how a systematic phenomenology of GPD models based on LFWFs can be achieved with the help of the PARTONS framework, here using DVCS data. This paves the way for a unified phenomenology of GPDs and TMDs at the level of LFWFs, with the final goal of hadron tomography.

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From Bethe–Salpeter Wave functions to Generalised Parton Distributions

Cited by 66 publications

References 167 publications

Spatial and momentum imaging of the pion and kaon

Spatial and momentum imaging of the pion and kaon

Nucleon Parton Distribution Amplitude: A Scalar Diquark Picture

Phenomenology with the PARTONS software of Generalized Parton Distribution models built from Light-Front Wave-functions

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