Tagging the pion quark structure in QCD

Bakulev, A. P.; Михайлов, С. В.; Stefanis, N. G.

doi:10.1103/physrevd.73.056002

Cited by 64 publications

(95 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In particular, the shape of the pion DA has been extensively discussed due to the nature of the pion as the massless Nambu-Goldstone boson [5,6]. Finding the fundamental nonperturbative information of QCD motivated many theoretical studies to calculate meson DAs using nonperturbative methods such as the QCD sum rule [3,[7][8][9][10][11][12][13][14][15], the chiral-quark model from the instanton vacuum [16][17][18], the Nambu-JonaLasinio (NJL) model [19,20], the Dyson-Schwinger equation (DSE) approach [21,22], and the light-front quark model (LFQM) [23,24]. Among them, the LFQM appears to be one of the most effective and efficient tools in studying hadron physics as it takes advantage of the distinguished features of the light-front dynamics (LFD) [25].…”

Section: Introductionmentioning

confidence: 99%

Two-particle twist-3 distribution amplitudes of the pion and kaon in the light-front quark model

Choi

2017

Phys. Rev. D

View full text Add to dashboard Cite

We investigate the two-particle twist-3 distribution amplitudes (DAs) of the pseudoscalar mesons, in particular pseudoscalar (φ P 3;M (x)) and pseudotensor (φ σ 3;M (x)) DAs of pion and kaon, in the lightfront quark model based on the variational principle. We find that the behavior of the conformal symmetry in each meson distribution amplitude depends on the chiral limit characteristics of the light-front trial wave function taken in the variational principle. We specifically take the two different light-front trial wave functions, Gaussian vs. power-law type, and discuss their characteristics of the conformal symmetry in the chiral symmetry limit as well as their resulting degree of the conformal symmetry breaking in φ P 3;M (x) and φ σ 3;M (x) depending on the trial wave function taken in the computation. We present numerical results of transverse moments, Gegenbauer-moments and ξ-moments and compare them with other available model estimates. The SU(3) flavor-symmetry breaking effect is also quantified with the numerical computation.

show abstract

Section: Introductionmentioning

confidence: 99%

Two-particle twist-3 distribution amplitudes of the pion and kaon in the light-front quark model

Choi

2017

Phys. Rev. D

View full text Add to dashboard Cite

show abstract

“…Moreover, one observes that both predictions overlap with the band of the results derived in [2] and indicate conformity with endpoint-vanishing (or even endpoint-suppressed) pion DAs, like in the BMS formalism [18,34].…”

mentioning

confidence: 67%

“…The CLEO data favor a pion DA close to the asymptotic (as) form [31,32] excluding pion DAs of the Chernyak-Zhitnitsky (CZ) [33] type. Later, more detailed analyses of these data [10,34] have excluded ϕ CZ π and ϕ as π at the 4σ and the 3σ level, respectively. To achieve an agreement with the CLEO data with 1σ accuracy, one has to use endpoint-suppressed pion DAs of the form derived in [18] with the help of QCD sum rules with nonlocal condensates.…”

Section: Data Explanationsmentioning

confidence: 99%

Pion-Photon Transition Form Factor and Pion Distribution Amplitude in QCD: Facing the Enigmatic Behavior of the BaBar Data

Stefanis

Bakulev²,

Михайлов³

et al. 2012

Nuclear Physics B - Proceedings Supplements

View full text Add to dashboard Cite

We present an extended analysis of the data for the pion-photon transition form factor from different experiments, CELLO, CLEO, and BaBar, and discuss various theoretical approaches which try to reason from them. We focus on the divergent behavior of the BaBar data for the pion and those for the η(η ′ ) pseudoscalar mesons and comment on recently proposed explanations for this discrepancy. We argue that it is not possible at present to accommodate these data within the standard QCD framework self-consistently. Keywords:Meson transition form factors, pion distribution amplitude, QCD (light-cone) sum rules 1. Two-photon processes for π 0 and η(η ′ ) in QCD At the basis of applications of Quantum Chromodynamics (QCD), which governs the interactions of quarks and gluons, is the property of factorization of corresponding amplitudes in hard processes. Proving the property of factorization means that a hadronic process at large momentum transfer can be dissected in a product of distinct quantities each associated with separate regimes of dynamics. Then, subprocesses developing at short distances and involving partons-quarks and gluons-can be accurately described in a systematic way within perturbation theory. On the other hand, the dynamical (mainly nonperturbative) features of the hadron binding effects are encoded in correlators, which contain quark and gluon field operators, and can be parameterized in terms of light-cone wave functions and parton distribution functions. These quantities are process-independent and describe the universal interpolation between hadrons and their quark and gluon degrees of freedom as distributions over the fractions of * Corresponding author * * Speaker of the talk at the "Psi-to-Phi" Conference Email address: stefanis@tp2.ruhr-uni-bochum.de (N. G. Stefanis) the longitudinal and intrinsic transverse momenta carried by the partons. They have to be determined by nonperturbative methods (models), lattice calculations, or from the data.The (spacelike) transition form factors (TFFs) of pseudoscalar mesons, in particular the pion, have been extensively studied within QCD, because in leading order they are purely electromagnetic processes with the binding QCD effects being factorized out into the pion distribution amplitude (DA)-see [1] for a review and [2] for recent references. This means that for a highly virtual photon with the four-momentum transfer Q 2 and a quasi-real photon with q 2 → 0, the TFF can be cast as the convolution of the twist-two hard-scattering amplitude T (Q 2

show abstract

“…In the context of the LCSR and renormalon methods this form factor was analyzed in Refs. [28,38]. Preliminary calculations demonstrate that the twist-2 term in the LCSR expression for F πγ (Q 2 ) found using ϕ hol (u) exceeds the measured experimental data [39].…”

Section: Numerical Resultsmentioning

confidence: 99%

Pion distribution amplitude from holographic QCD and the electromagnetic form factorFπ(Q2)

Agaev

Nobary

2008

Phys. Rev. D

View full text Add to dashboard Cite

The holographic QCD prediction for the pion distribution amplitude (DA) ϕ hol (u) is used to compute the pion spacelike electromagnetic form factor Fπ(Q 2 ) within the QCD light-cone sum rule method. In calculations the pion's renormalon-based model twist-4 DA, as well as the asymptotic twist-4 DA are employed. Obtained theoretical predictions are compared with experimental data and with results of the holographic QCD.

show abstract

Tagging the pion quark structure in QCD

Cited by 64 publications

References 38 publications

Two-particle twist-3 distribution amplitudes of the pion and kaon in the light-front quark model

Two-particle twist-3 distribution amplitudes of the pion and kaon in the light-front quark model

Pion-Photon Transition Form Factor and Pion Distribution Amplitude in QCD: Facing the Enigmatic Behavior of the BaBar Data

Pion distribution amplitude from holographic QCD and the electromagnetic form factorFπ(Q2)

Contact Info

Product

Resources

About