English

Strong evidence for nucleon resonances near 1900\,MeV

Nuclear Experiment 2017-12-27 v1

Abstract

Data on the reaction γpK+Λ\gamma p\to K^+\Lambda from the CLAS experiments are used to derive the leading multipoles, E0+E_{0+}, M1M_{1-}, E1+E_{1+}, and M1+M_{1+}, from the production threshold to 2180\,MeV in 24 slices of the invariant mass. The four multipoles are determined without any constraints. The multipoles are fitted using a multichannel L+PL+P model which allows us to search for singularities and to extract the positions of poles on the complex energy plane in an almost model-independent method. The multipoles are also used as additional constraints in an energy-dependent analysis of a large body of pion and photo-induced reactions within the Bonn-Gatchina (BnGa) partial wave analysis. The study confirms the existence of poles due to nucleon resonances with spin-parity JP=1/2;1/2+J^P = 1/2^-; 1/2^+, and 3/2+3/2^+ in the region at about 1.9\,GeV.

Keywords

Cite

@article{arxiv.1712.07549,
  title  = {Strong evidence for nucleon resonances near 1900\,MeV},
  author = {A. V. Anisovich and V. Burkert and M. Hadžimehmedović and D. G. Ireland and E. Klempt and V. A. Nikonov and R. Omerović and H. Osmanović and A. V. Sarantsev and J. Stahov and A. Švarc and U. Thoma},
  journal= {arXiv preprint arXiv:1712.07549},
  year   = {2017}
}

Comments

4 pages, 2 figures