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arXiv · hep-ph/9703395

The hard scattering amplitude for the higher helicity components of the pion form factor

Fuguang Cao·J. Cao·T. Huang·B. Q. Ma
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Abstract

For obtaining the spin space wave function of the pion meson in the light-cone formalism from the naive quark model, it is necessary to take into account Wigner rotation. Consequently there are higher helicity ($λ_1+λ_2=\pm 1$) components in the light-cone spin space wave function of the pion besides the usual helicity ($λ_1+λ_2=0$) components. For the pion electromagnetic form factor, we calculate the hard-scattering amplitude for the higher helicity components in the light-cone perturbation theory. It is found that the hard-scattering amplitude for the higher helicity components is of order $1/Q^4$, which is vanishingly small compared to that of the ordinary helicity component at very high $Q^2$ but should be considered in the $Q^2$ region where experimental data are available.

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Fuguang Cao, J. Cao, T. Huang, B. Q. Ma. 1997-03-24. The hard scattering amplitude for the higher helicity components of the pion form factor. https://doi.org/10.1103/physrevd.55.7107

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