An extended model for nonet pseudo-scalar meson fragmentation

An SU(3) symmetric model with high predictivity for octet meson (π,K) quark fragmentation functions with a simple approach to SU(3) symmetry breaking (due to the relatively heavy strange quarks) is extended to the singlet sector, with some reasonable assumptions, in order to study η and η fragmentation. Due to the presence of SU(3) symmetry, fits to the π and K data help to constrain the fragmentation functions for η and η mesons. The use of 2-jet and 3-jet (especially the gluon jet) inclusive meson production in e e collisions and π, η inclusive production in p p collisions enable the extraction of the gluon fragmentation functions as well. While sea quarks in strange mesons (K, K, K 0 ) and the heavier η, η mesons are suppressed by a factor of λH = m 2 π/m 2 H . 0.1 for H = K, η, η , the gluons are not as severely suppressed: f g ∼ 0.3–0.35. A detailed parametrisation of the three independent fragmentation functions V (x,Q), γ(x,Q), and Dg(x,Q ) are given in LO QCD; all nonet meson gluon fragmentation functions and quark fragmentation functions of all flavours can be expressed in terms of these functions with a few model parameters including λH and fg. The data prefer a nonet mixing angle −24◦ ≤ θP ≤ −16◦ and rule out no-mixing. PACS Nos: 13.87.Fh, 13.65.+i, 13.60.Le, 14.40.Aq, 13.85.Ni