2025/09/08 by Yin Huang, Xurong Chen, Huang, Yin +1
Computer Science · Mathematics · #Advanced Mathematical Modeling in Engineering #FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #High Energy Physics - Phenomenology (hep-ph) #Nonlinear Partial Differential Equations #Spectral Theory in Mathematical Physics
paper · pdf · doi:10.48550/arxiv.2509.06353
openalex publication_date 2025/09/08 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
About 18 years ago, the BABAR and the Belle Collaborations reported evidence for a new cc structure near 3900~MeV in e+e- → DD, triggering debate over whether it represents a genuine hadronic state or arises from interference effects and the opening of the D*D threshold. The issue remained unsettled until 2024, when BESIII, with an enlarged e+e- → DD sample, confirmed the presence of the G(3900) structure, reviving discussion of its nature. Although it has been proposed as a P-wave DD* molecular state, no consensus has emerged, and interference effects remain a plausible explanation. In this Letter, we show that analyzing the e+e-→ DD cross section as a function of the transverse momentum of the final-state D meson reveals a prominent Jacobian peak. This feature cannot be generated by interference effects alone and thus provides direct evidence for the existence of G(3900). Moreover, the peak position is highly sensitive to the actual mass of G(3900), offering a precise determination method. The criterion illustrated by G(3900) can be extended to other hadronic systems, offering a powerful tool to identify genuine resonances.