2017/12/04 by A. Guskov, Guskov, A.
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #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.1712.01345
openalex publication_date 2017/12/04 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Exotic charmonium-like states have been targeted by various experiments in the last 15 years, but their nature still is unknown. Photo-(muo)production is a new promising instrument to study them. COMPASS, a fixed target experiment at CERN, analyzed the full set of the data collected with a muon beam between 2002 and 2011, covering the range from 7 GeV to 19 GeV in the centre-of-mass energy of the (virtual)photon-nucleon system. Production of the X(3872) state in the reaction μ+~N → μ+(J/ψπ+π- )π± N' has been observed with a statistical significance of around 5 σ. The shape of the π+π- mass distribution from the decay X(3872)→ J/ψπ+π- shows disagreement with previous observations. The product of the cross section and the branching fraction of the X(3872) decay into J/ψππ is estimated as 71±28(stat)±39(syst) pb. The results obtained for the production of the Zc±(3900) are also reported as well as future perspectives.