Hard scattering amplitude for the higher helicity components of the pion form factor

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 the Wigner rotation. Consequently there are higher helicity (λ₁+λ₂=±1) components in the light-cone spin space wave function of pion in addition to the usual helicity (λ₁+λ₂=0) components. For the pion electromagnetic form factor, we calculate the hard-scattering amplitude for the higher helicity components in light-cone perturbation theory. It is found that the hard-scattering amplitude for the higher helicity components is of order 1/Q⁴, which is vanishingly small compared to that of the ordinary helicity components at very high Q² but should be considered in the Q² region where experimental data are available.