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RESEARCH PRODUCT
The role of charged exotic states in e+e− → ψ(2S) π+π−
Daniel A. S. MolnarIgor DanilkinMarc Vanderhaeghensubject
PhysicsNuclear and High Energy PhysicsWork (thermodynamics)010308 nuclear & particles physicsDispersion theoryState (functional analysis)01 natural scienceslcsh:QC1-999Nuclear physicsPionDistribution (mathematics)0103 physical sciencesIntermediate stateInvariant mass010306 general physicsDispersion (chemistry)Nuclear Experimentlcsh:Physicsdescription
Abstract In this work, we use the dispersion theory to provide a physical description of recent BESIII data on the reaction e + e − → ψ ( 2 S ) π + π − . Taking into account explicitly the effects of charged exotic intermediate states in the t- and u-channels as well as the two-pion final state interaction, we describe the invariant mass distribution for four different e + e − center-of-mass energies. The effects of the ππ rescattering are accounted for in a single channel Omnes approach which is found to explain the ππ-invariant mass distributions at all e + e − center-of-mass energies. For q = 4.226 GeV and q = 4.258 GeV the already established charged exotic state Z c ( 3900 ) is considered as the intermediate state, whereas for q = 4.358 GeV the rescattering of pions dominates the fits. For the highest energy, q = 4.416 GeV, a heavier charged exotic state with mass m Z c = 4.016 ( 4 ) GeV and width Γ Z c = 52 ( 10 ) MeV is essential to describe the experimental data. Although the mass of this state is consistent with the established Z c ( 4020 ) , its width is significantly larger.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2019-10-01 | Physics Letters B |