Experimental Advances on Light Baryon Spectroscopy at BESIII Experiment

Abstract

The BESIII experiment is currently the world's only electron-positron collider operating in the tau-charm physical energy region. Since starting data taking in 2009, BESIII has accumulated the world's largest data set in the center-of-mass energy range of 1.84-4.95 GeV, including approximately 10 billion $J/ψ$ events and 3 billion $ψ(3686)$ events, together with extensive data on open-charm hadron pair production near threshold regions. These unique datasets, characterized by high statistics and low background, provide unprecedented experimental conditions for studying light baryon spectroscopy. This article systematically reviews the progress made by BESIII in baryon spectroscopy, with a focus on recent breakthrough achievements, including the discovery of excited nucleon states, $Λ$ hyperon states, $Σ$ hyperon states, $Ξ$ hyperon states and $Ω^{-}$ hyperon states. These results expand the spectrum of baryon excited states and provide crucial experimental support for understanding non-perturbative QCD and resolving the ``missing baryon resonances'' problem.

Figures (15)

• Figure 1: Schematic diagram of the BESIII detector.
• Figure 2: Dalitz plot of $M^2_{p\pi^0}$ versus $M^2_{\bar{p}\pi^0}$ and distributions of $M_{p\bar{p}}$, $M_{p\pi^0}$ and $M_{\bar{p}\pi^0}$ in $\psi(3686)\to p\bar{p}\pi^0$ from BESIII experiment BESIII:2024vqu.
• Figure 3: Dalitz plot of $M^2_{p\eta}$ versus $M^2_{\bar{p}\eta}$ and distributions of $M_{p\bar{p}}$, $M_{p\eta}$ and $M_{\bar{p}\eta}$ in $\psi(3686)\to p\bar{p}\eta$ from BESIII experiment BESIII:2024vqu.
• Figure 4: Distributions of $M(\eta\Lambda)$, $M(\eta\bar{\Lambda})$ and $M(\Lambda\bar{\Lambda})$ in $\psi(3686)\to\Lambda\bar{\Lambda}\eta$ from BESIII experiment BESIII:2022cxi.
• Figure 5: Distributions of $M^2(\Lambda \omega)$ (Tob) and $M^2(\bar{\Lambda} \omega)$ (Bottom) in $\psi(3686) \to \Lambda \bar{\Lambda} \omega$ from BESIII experiment BESIII:2022fhe, the red solid curves show the shape of $\Lambda^*$-$\bar{\Lambda}^*$ resonances, the blue solid curves show the background described by $\omega$ sidebands and the green solid curves show the shapes from the non-resonant decay.