Dispersion-theoretical analysis of the electromagnetic form factors of the hyperon
Helmholtz Institut für Strahlen- und Kernphysik and Bethe Center for Theoretical Physics, Universität Bonn, 53115, Bonn, Germany
2 Department of Physics, Institut für Kernphysik, Technische Universität Darmstadt, 64289, Darmstadt, Germany
3 ExtreMe Matter Institute EMMI and Helmholtz Forschungsakademie Hessen für FAIR (HFHF), GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291, Darmstadt, Germany
4 Institute for Advanced Simulation and Institut für Kernphysik, Forschungszentrum Jülich, 52425, Jülich, Germany
5 Tbilisi State University, 0186, Tbilisi, Georgia
Accepted: 21 November 2022
Published online: 3 December 2022
The electromagnetic form factors of the hyperon in the time-like region are determined precisely through a dispersion-theoretical analysis of the world data for the cross section of the annihilation process . The spectral function is represented by a superposition of narrow and broad vector meson poles. We test different scenarios for the spectral function and obtain a good description of the world data in the time-like region. The uncertainties in the extracted form factors are estimated by means of the bootstrap sampling method. The analytical continuation of the form factors to the space-like region introduces large errors due to the lack of data. When the electric radius from chiral perturbation theory is taken as a constraint, the magnetic radius is predicted as fm. We also extract various vector meson to baryon coupling constants.
© The Author(s) 2022
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