Constraints on the light pseudoscalar meson distribution amplitudes from their meson-photon transition form factors

Journal Article · Sat Oct 01 04:00:00 EDT 2011 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.84.074011· OSTI ID:21607769

Xinggang, Wu; Tao, Huang ^[1]

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1. Department of Physics, Chongqing University, Chongqing 401331 (China)

The meson-photon transition form factors {gamma}{gamma}*{yields}P (P stands for {pi}, {eta} and {eta}') provide strong constraints on the distribution amplitudes of the pseudoscalar mesons. In this paper, these transition form factors are calculated under the light-cone perturbative QCD approach, in which both the valence and nonvalence quarks' contributions have been taken into consideration. To be consistent, a unified wave function model is adopted to analyze these form factors. It is shown that with the proper charm component f{sub {eta}}'{sup c}{approx}-30 MeV and a moderate DA with B{approx}0.30, the experimental data on Q{sup 2}F{sub {eta}{gamma}}(Q{sup 2}) and Q{sup 2}F{sub {eta}'{gamma}}(Q{sup 2}) in the whole Q{sup 2} region can be explained simultaneously. Furthermore, a detailed discussion on the form factors' uncertainties caused by the constituent quark masses m{sub q} and m{sub s}, the parameter B, the mixing angle {phi}, and f{sub {eta}'}{sup c} are presented. It is found that, by adjusting these parameters within their reasonable regions, one can improve the form factor to a certain degree but cannot solve the puzzle for Q{sup 2}F{sub {pi}{gamma}}(Q{sup 2}), especially to explain the behavior of the {pi}-{gamma} form factor within the whole Q{sup 2} region consistently. We hope further experimental data on these form factors in the large Q{sup 2} region can clarify the present situation.

• OSTI ID: 21607769
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 7 Vol. 84; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
AMPLITUDES
BOSONS
DIMENSIONLESS NUMBERS
DISTRIBUTION
ELEMENTARY PARTICLES
ENERGY RANGE
FERMIONS
FIELD THEORIES
FORM FACTORS
FUNCTIONS
HADRONS
LIGHT CONE
LIMITING VALUES
MASS
MASSLESS PARTICLES
MESONS
MEV RANGE
MEV RANGE 10-100
PARTICLE PROPERTIES
PHOTONS
PSEUDOSCALAR MESONS
QUANTUM CHROMODYNAMICS
QUANTUM FIELD THEORY
QUARKS
SPACE-TIME
WAVE FUNCTIONS
WEINBERG ANGLE