Quark distributions in the nucleon by the semi-inclusive reaction on the proton and helium-3 target

We investigate the spin asymmetries which will be measured by semi-inclusive reactions on proton targets and helium-3 targets with tagged charged pions and kaons. By using the quark parton model, we relate the spin asymmetries to the quark spin distributions in the nucleon. We also use the parametrized fragmentation functions and the existing parametrizations of polarized and unpolarized quark distributions. Then we predict the spin asymmetries. We show that we can study the quark distributions in the neutron with the helium-3 target. We find useful properties for experimental analysis: The spin asymmetry changes little if kaons are taken into account, and it is almost independent of the z-cut.