The Research Of NΣ* Dibaryon Of Strangeness-1

The study of hadron structure and hadron-hadron interaction has always been a frontier topic in particle physics and nuclear physics.Since the COSY Collaboration confirmed the existence of the six-quark state d*,exploring the existence of other dibaryons,both theoretically and experimentally,has aroused extensive attention.Quantum Chromodynamics(QCD)is believed as the basic theory of strong interaction.We had ever proposed the chiral SU(3)quark model which not only satisfies the chiral symmetry required by QCD theory,but also the number of model parameters is greatly reduced and the quark-chiral field coupling constant can further be determined by experimental data.Based on the above,we further proposed the extended chiral SU(3)quark model by introducing the quark-vector chiral field coupling.Applying this model,the ground-state property of baryons,binding energy of deuteron,and nucleon-nucleon(N-N)and nucleon-hyperon(N-Y)scattering data can be reasonably described within the framework of resonating group method(RGM).Then,using the same parameters,we further predicted the binding energy ofd~*and surprisingly confirmed by COSY experiment ten years later,illustrating the rationality and effectiveness of our model and surely suitable to predict the existence of other dibaryon candidates.In this work,first,we construct the wave function of octet-decuplet dibaryon,NΣ*system,its strangeness-1,spin S=2 and isospin T=1/2.Second,by using a new wave function expansion method,we calculate the matrix elements in spin-flavor-color space both in single-channel and coupled-channel calculation.Finally,we perform the dynamical calculation ofNΣ*system in the extended chiral SU(3)quark model.The binding energy and root mean square radius ofNΣ*system will be studied,the contribution of various interactions to the binding energy is analyzed.We obtain the binding energy and root mean square radius in single-channel calculation and the result show thatNΣ*system would form bound state.We also investigate the coupled-channel effect fromΣΔsystem,and find theNΣ*system would become more bound.In a word,both in single-channel and coupled-channel calculations,NΣ*system would form bound state.This study of strangeness-1 system is very interesting,and it would be helpful to find more possible dibaryon exotic state candidates,especially strange system of octet-decuplet dibaryon.