An extended quark recombination model with valence quark annihilation compared to inclusive π+/π− ratios

Valence quark annihilation with subsequent recombination is considered as the dominant nonscaling process contributing to lowp⊥ pion production in the proton fragmentation region at medium energies. With the aid of a Kuti-Weisskopf model for quark distribution functions the inclusive ratios π+/π− have been calculated and compared to data forHp→π± +anything withH=π±,K−,\(\bar p\). Each of these beam particles carries valence antiquarks. The dependence of the ratios on the Feynman variablex and their energy dependence is well reproduced.