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Title: Meson Transition Form Factors in Light-Front Holographic QCD

Abstract

We study the photon-to-meson transition form factors (TFFs) F{sub M{gamma}}(Q{sup 2}) for {gamma}{gamma}* {yields} M using light-front holographic methods. The Chern-Simons action, which is a natural form in 5-dimensional anti-de Sitter (AdS) space, leads directly to an expression for the photon-to-pion TFF for a class of confining models. Remarkably, the predicted pion TFF is identical to the leading order QCD result where the distribution amplitude has asymptotic form. The Chern-Simons form is local in AdS space and is thus somewhat limited in its predictability. It only retains the q{bar q} component of the pion wavefunction, and further, it projects out only the asymptotic form of the meson distribution amplitude. It is found that in order to describe simultaneously the decay process {pi}{sup 0} {yields} {gamma}{gamma} and the pion TFF at the asymptotic limit, a probability for the q{bar q} component of the pion wavefunction P{sub q{bar q}} = 0.5 is required; thus giving indication that the contributions from higher Fock states in the pion light-front wavefunction need to be included in the analysis. The probability for the Fock state containing four quarks (anti-quarks) which follows from analyzing the hadron matrix elements, P{sub q{bar q}q{bar q}} {approx} 10%, agrees with themore » analysis of the pion elastic form factor using light-front holography including higher Fock components in the pion wavefunction. The results for the TFFs for the {eta} and {eta}{prime} mesons are also presented. The rapid growth of the pion TFF exhibited by the BABAR data at high Q{sup 2} is not compatible with the models discussed in this article, whereas the theoretical calculations are in agreement with the experimental data for the {eta} and {eta}{prime} TFFs.« less

Authors:
; ;
Publication Date:
Research Org.:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1017232
Report Number(s):
SLAC-PUB-14462
arXiv:1105.3999; TRN: US1103185
DOE Contract Number:  
AC02-76SF00515
Resource Type:
Journal Article
Journal Name:
Submitted to Physical Review D
Additional Journal Information:
Journal Name: Submitted to Physical Review D
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; AMPLITUDES; DECAY; DISTRIBUTION; FORM FACTORS; HADRONS; HOLOGRAPHY; MATRIX ELEMENTS; MESONS; PIONS; PROBABILITY; QUANTUM CHROMODYNAMICS; QUARKS; Phenomenology-HEP,HEPPH, HEPTH

Citation Formats

Brodsky, Stanley J, /SLAC, Cao, Fu-Guang, /Massey U., de Teramond, Guy F, and /Costa Rica U. Meson Transition Form Factors in Light-Front Holographic QCD. United States: N. p., 2011. Web. doi:10.1103/PhysRevD.84.075012.
Brodsky, Stanley J, /SLAC, Cao, Fu-Guang, /Massey U., de Teramond, Guy F, & /Costa Rica U. Meson Transition Form Factors in Light-Front Holographic QCD. United States. https://doi.org/10.1103/PhysRevD.84.075012
Brodsky, Stanley J, /SLAC, Cao, Fu-Guang, /Massey U., de Teramond, Guy F, and /Costa Rica U. 2011. "Meson Transition Form Factors in Light-Front Holographic QCD". United States. https://doi.org/10.1103/PhysRevD.84.075012. https://www.osti.gov/servlets/purl/1017232.
@article{osti_1017232,
title = {Meson Transition Form Factors in Light-Front Holographic QCD},
author = {Brodsky, Stanley J and /SLAC and Cao, Fu-Guang and /Massey U. and de Teramond, Guy F and /Costa Rica U.},
abstractNote = {We study the photon-to-meson transition form factors (TFFs) F{sub M{gamma}}(Q{sup 2}) for {gamma}{gamma}* {yields} M using light-front holographic methods. The Chern-Simons action, which is a natural form in 5-dimensional anti-de Sitter (AdS) space, leads directly to an expression for the photon-to-pion TFF for a class of confining models. Remarkably, the predicted pion TFF is identical to the leading order QCD result where the distribution amplitude has asymptotic form. The Chern-Simons form is local in AdS space and is thus somewhat limited in its predictability. It only retains the q{bar q} component of the pion wavefunction, and further, it projects out only the asymptotic form of the meson distribution amplitude. It is found that in order to describe simultaneously the decay process {pi}{sup 0} {yields} {gamma}{gamma} and the pion TFF at the asymptotic limit, a probability for the q{bar q} component of the pion wavefunction P{sub q{bar q}} = 0.5 is required; thus giving indication that the contributions from higher Fock states in the pion light-front wavefunction need to be included in the analysis. The probability for the Fock state containing four quarks (anti-quarks) which follows from analyzing the hadron matrix elements, P{sub q{bar q}q{bar q}} {approx} 10%, agrees with the analysis of the pion elastic form factor using light-front holography including higher Fock components in the pion wavefunction. The results for the TFFs for the {eta} and {eta}{prime} mesons are also presented. The rapid growth of the pion TFF exhibited by the BABAR data at high Q{sup 2} is not compatible with the models discussed in this article, whereas the theoretical calculations are in agreement with the experimental data for the {eta} and {eta}{prime} TFFs.},
doi = {10.1103/PhysRevD.84.075012},
url = {https://www.osti.gov/biblio/1017232}, journal = {Submitted to Physical Review D},
number = ,
volume = ,
place = {United States},
year = {Wed Jun 22 00:00:00 EDT 2011},
month = {Wed Jun 22 00:00:00 EDT 2011}
}