Broad resonance structure in $e^+e^-\to f_1(1285)\pi^+\pi^-$ and higher $\rho$-meson excitations

TL;DR

This paper analyzes the broad resonance structure near 2 GeV in the process $e^+e^- o f_1(1285)\pi^+\pi^-$, suggesting contributions from higher $ ho$-meson excitations and indicating potential signals of $ ho(5S)$ around 2.5 GeV.

Contribution

The work provides a detailed interpretation of the resonance structure involving higher $ ho$-mesons, including $ ho(1900)$, $ ho(2150)$, and a possible $ ho(5S)$ signal, enhancing understanding of higher $ ho$ states.

Findings

The broad resonance near 2 GeV can be explained by $ ho(1900)$ and $ ho(2150)$ contributions.

The data suggests a possible $ ho(5S)$ signal around 2.5 GeV.

The analysis offers guidance for future experiments like BESIII and Belle II.

Abstract

Recently, the BaBar Collaboration reported a broad resonance structure near 2 GeV when analyzing the $e^+e^-\to f_1(1285)\pi^+\pi^-$ process, which provides a good opportunity to study the higher $\rho$-mesonic states. When considering the $\rho(1900)$ and $\rho(2150)$ contributions, the experimental data of the cross section of $e^+e^-\to f_1(1285)\pi^+\pi^-$ around 2 GeV can be well depicted, especially the observed broad resonance structure in $e^+e^-\to f_1(1285)\pi^+\pi^-$ containing two substructures is suggested by the present work. Additionally, we also indicate a possible signal of $\rho(5S)$ around 2.5 GeV in the $e^+e^-\to f_1(1285)\pi^+\pi^-$ process. The obtained result may provide a valuable hint to identify higher $\rho$ mesons, which will be a new task for the BESIII and Belle II experiments with the accumulation of higher precision data.