New approach to finding invisible states in e⁺e^- annihilation and application to BESIII data

2023/11/08 by Glennys R. Farrar, Qiming Li, Farrar, Glennys R. +3
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #High Energy Physics - Lattice (hep-lat) #High Energy Physics - Phenomenology (hep-ph) #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions

paper · pdf · doi:10.48550/arxiv.2311.04654

openalex publication_date 2023/11/08 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28

Abstract

We compare precision e⁺e^- to μ⁺μ^- cross section measurements by BESIII in the E_cm =3.8-4.6 GeV range, to predictions based on measured R_had data. The consistency is poor (p-value <0.012). Allowing for resonance contributions not seen in R_had gives an excellent fit, with the state at 4421 MeV ( 4.6 sigma) giving insight into the psi(4415) and the 3.1 sigma structure at 4211 MeV, if confirmed, being a new, very narrow resonance. This analysis shows the power of precision e⁺e^- to μ⁺μ^- measurements to uncover or probe otherwise difficult to access states.

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