J/psi辐射衰变中赝标量胶球和1-+奇特态的寻找与研究

Hadron spectroscopy is a key tool in the study of nonperturbative Quantum Chromodynamics. Experimental search of new forms of hadrons is extremely important to the validation and development of the fundamental theory of the strong interactions. Partial wave analysis (PWA) techniques are the state-of-the-art way to disentangle contributions from individual, and even small, resonances and to extract the resonance's spin-parity, mass, width and decay properties with high sensitivity and accuracy..Radiative J/ψ decay is a gluon-rich process and has long been regarded as one of the most promising hunting grounds for exotic states with gluonic degrees of freedom (glueball and hybrid). Using the high statistics data collected at BESIII, this project systematically studies the J/ψ radiative decays into πππ, ηπ^0π^0, K_S K_S π^0 and η’π^0π^0. PWA technique is used to extract the resonance properties precisely. The series of PWA studies will systematically map out the pseudoscalar spectrum and will focus on the region above 2 GeV, where the ground state of pseudoscalar glueball and isoscalar 1-+ hybrid are predicted. This project will provide significant inputs to the understanding of meson spectroscopy and the study of glueball and hybrid. Meanwhile, this project will promote the development of BES’s PWA methodology and technique.

强子谱学是研究非微扰量子色动力学的重要工具。寻找和研究新型强子，对于检验和发展物质强相互作用基本理论具有重大意义。分波分析方法可以精确测量粒子的自旋宇称，共振态参数和衰变性质，是强子谱学关键的研究手段。.J/ψ辐射衰变被誉为是寻找和研究有胶子自由度的新型强子（胶球和混杂态）的理想场所之一。本项目利用BESIII高统计量数据,选取J/ψ辐射衰变到πππ，ηπ^0π^0， K_S K_S π^0和η’π^0π^0等过程，采用分波分析方法进行系统的研究。本项目将为厘清赝标量介子谱提供关键的实验信息。理论预期基态赝标量胶球和同位旋为0的1-+混杂态在2GeV以上能区，本项目将重点在这一能区寻找和研究胶球和混杂态。同时，本项目能有效促进BES分波分析方法和技术的完善。

强子谱学是研究非微扰量子色动力学的重要工具。寻找和研究新型强子，对于检验和发展物质强相互作用基本理论具有重大意义。分波分析方法可以精确测量粒子的自旋宇称，共振态参数和衰变性质，是强子谱学关键的研究手段。.J/ψ辐射衰变被誉为是寻找和研究有胶子自由度的新型强子（胶球和混杂态）的理想场所之一。本项目利用BESIII高统计量J/ψ数据进行系统的研究。标量方面，首次发现a0(980)-f0(980)混合，对其内部结构提供重要约束；完成J/ψ→γK_S K_S分波分析，对标量胶球有重要意义。赝标量方面，在J/ψ→γγϕ中首次发现η(1475)和X(1835)，为其味道结构提供了重要信息；在J/ψ→γK_S K_S η' 中首次发现赝标量胶球候选者X(2370)。.本项目为胶球等奇特强子态研究提供了关键的实验信息。同时，本项目有效促进BES分波分析方法和技术的完善。