Particle ratios in electroproduction of kaons and symmetry properties of the quark-parton model

Abstract

Previously (~), we reported a work on the particle ratios of hadrons (7: • K• and ~) produced in electron-proton (cp), electron-neutron (en) and electron-deuteron (ed) scattering in the framework of the quark-par ton model. The assumptions made were the following: i) The distribution functions of the sea quarks are SU3 symmetric, if) There are only one independent favoured fragmentat ion function, D~ and only one independent unfavoured fragmentat ion function, D~ for pions, iii) Similarly, for kaons, there are only two independent fragmentation functions, i.e., one favoured o n e , D K and one unfavoured one, D~:. Among the interesting results we derived, there are, for example, expressions for the rat ios of fragmentation functions which depend only on the experimental particle ratios but not on the distribution functions of quarks within the target . Unfortunately, however, the results could not be checked clearly with the available experimental da ta due to large errors. Based on the same assumptions as in ref. (~), we investigate in this note the further consequences by considering the different particle ratios, K• • off the same target. We shall est imate the approximate values of the fragmentation functions for kaons, ~)K and DE by using the experimental da ta (2). The particle ratios in electroproduction, are expressed as follows: for the proton target