2002/12/19 by Valeriu Ioan Zetocha, Valeriu Zetocha, Thomas Schäfer +1 · 1 citation
Physics and Astronomy · #Geometry #Glueball #Hadron #High-Energy Particle Collisions Research #Instanton #Meson #Particle physics #Particle physics theoretical and experimental studies #Physics #Pseudoscalar #Pseudoscalar meson #Quantum Chromodynamics and Particle Interactions #Quarkonium #Scalar (mathematics) #Scalar meson #hep-ph
paper · pdf · doi:10.1103/physrevd.67.114003
published as Phys.Rev. D67 (2003) 114003 · 29 pages, added references
arxiv created 2002/12/19 · openalex publication_date 2003/06/02 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We study instanton contributions to hadronic decays of the scalar glueball, the pseudoscalar charmonium state \ensuremathηc, and the scalar charmonium state \ensuremathχc. Hadronic decays of the \ensuremathηc are of particular interest. The three main decay channels are KK\ensuremathπ,\ensuremathη\ensuremathπ\ensuremathπ and \ensuremathη^\ensuremath'\ensuremathπ\ensuremathπ, each with an unusually large branching ratio \ensuremath∼5%. On the quark level, all three decays correspond to an instanton type vertex (cc)(ss)(dd)(\ifmmode u\else \=u\fiu). We show that the total decay rate into three pseudoscalar mesons can be reproduced using an instanton size distribution consistent with phenomenology and lattice results. Instantons correctly reproduce the ratio B(\ensuremathπ\ensuremathπ\ensuremathη)/B(\ensuremathπ\ensuremathπ\ensuremathη^\ensuremath') but overpredict the ratio B(KK\ensuremathπ)/B[\ensuremathπ\ensuremathπ\ensuremathη(\ensuremathη^\ensuremath')]. We consider the role of scalar resonances and suggest that the decay mechanism can be studied by measuring the angular distribution of decay products.