2005/07/31 by Shi-Lin Zhu · 8 citations
Physics and Astronomy · #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ex #hep-lat #hep-ph
paper · pdf · doi:10.1016/j.physletb.2005.08.068
published as Phys.Lett.B625:212,2005 · some references added
arxiv created 2005/08/09 · openalex publication_date 2005/08/30 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/29
The recently observed Y(4260) lies far above the decay threshold with a width less than 100 MeV. We argue that it's very difficult to accommodate Y(4260) as a conventional c c radial excitation or a D-wave state. It can't be a hadronic molecule. Its production mechanism and special decay pattern do not favor the glueball interpretation. If Y(4260) is a scalar tetraquark, it must be produced by the I=0 component of the virtual photon. Then the I=1, Iz=0 component of the virtual photon should have produced its isovector partner Y^′ (4260), which may be searched for in the decay channel π+π-π0 J/ψ using exactly the same database from the initial state radiation process. The observation/non-observation of Y^′ (4260) can easily confirm/reject the tetraquark hypothesis. However, a tetraquark far above threshold can fall apart into D D, D^∗ D very easily. Its not-so-large width and the non-observation of D D mode tend to disfavor the tetraquark hypothesis. Hence the only feasible interpretation is a hybrid charmonium if Y(4260) is \sl NOT an experimental artifact. At present, none of the experimental information from BABAR measurement is in conflict with the hybrid charmonium picture.