Pseudoscalar mixing in J/ψ and ψ(2S) decay

Abstract

Based on the branching fractions of J/ψ (ψ (2S)) → VP from different collaborations, pseudoscalar mixing is extensively discussed with a well established phenomenological model. The mixing angle is determined to be −14° by fitting to the new world average if only quark content is considered. After taking into account the gluonic content in η and η′ simultaneously, the investigation shows that η favors only consisting of light quarks, while the gluonic content of η′ is Z2η′ = 0.30±0.24.