Takatsugu Ishikawa(Research Center for Electron Photon Science, Tohoku University)
Description
The threshold structure with a spin parity of has been experimentally studied in the reaction at GeV. The structure is connected to the isoscalar -wave two-body system between the nucleon and nucleon resonance , or the chiral partner candidate of . By incorporating the known isovector resonance with a spin-parity of in the channel, we decompose the and invariant-mass spectra into the and contributions. From the analysis of and angular distributions, we determine the spin-parity of the first intermediate and systems. The spin-parity of the major component is found to be in the system, suggesting that some nucleon resonance contributes to photoproduction on the nucleon. It should be noted that is the main contributor for the elementary photoproduction. The talk will be based on [T. Ishikawa et al., arXiv:2105.10887].
Primary author
Takatsugu Ishikawa(Research Center for Electron Photon Science, Tohoku University)