Search for f(J)(2220) in radiative J/ψ decays

Area of Science:

• Particle Physics
• High-Energy Physics
• Quantum Chromodynamics

Background:

• The f(J)(2220) is a poorly understood meson resonance observed in J/ψ radiative decays.
• Previous experiments, like Mark III, reported evidence for this state, but its properties remain debated.

Purpose of the Study:

• To search for the f(J)(2220) resonance in radiative J/ψ decays (J/ψ→γf(J)(2220)).
• To investigate the f(J)(2220) decays into charged and neutral kaon pairs (K⁺K⁻ and K⁰SK⁰S).
• To set precise upper limits on the branching fractions for these processes.

Main Methods:

• Analysis of 460 fb⁻¹ of data collected by the BABAR detector at the PEP-II e⁺e⁻ collider.
• Reconstruction of J/ψ→γf(J)(2220) decays, with f(J)(2220) decaying into K⁺K⁻ and K⁰SK⁰S final states.
• Statistical analysis to set 90% confidence level upper limits on branching fractions.

Main Results:

• No significant evidence for the f(J)(2220) resonance was observed in the analyzed data.
• 90% confidence level upper limits on the product of branching fractions, B(J/ψ→γf(J)(2220)) × B(f(J)(2220)→K⁺K⁻ or K⁰SK⁰S), were established at the level of 10⁻⁵.
• These limits are below the central values reported by the Mark III experiment.

Conclusions:

• The absence of evidence for the f(J)(2220) in this high-statistics BABAR dataset challenges previous observations.
• The results provide stringent constraints on the existence and properties of the f(J)(2220) resonance.
• Further theoretical and experimental investigations are needed to clarify the nature of this particle or the discrepancy in observations.