Exact calculations of a quasibound state in the (K)over-bar (K)over-bar N system

0450502 - ÚJF 2016 RIV US eng J - Článek v odborném periodiku
Shevchenko, Nina V. - Haidenbauer, J.
Exact calculations of a quasibound state in the (K)over-bar (K)over-bar N system.
Physical Review. C. Roč. 92, č. 4 (2015), 044001. ISSN 0556-2813
Grant CEP: GA ČR(CZ) GA15-04301S
Institucionální podpora: RVO:61389005
Klíčová slova: K-P interactions * sigma-hyperon production * N three-body system
Kód oboru RIV: BE - Teoretická fyzika
Impakt faktor: 3.146, rok: 2015

For the (K) over bar (K) over bar interaction separable potentials are employed that are fitted to phase shifts obtained from two theoretical models. The first one is a phenomenological (K) over bar (K) over bar potential based on meson exchange, which is derived by SU(3) symmetry arguments from the Julich pi pi - (K) over bar K coupled-channels model. The other interaction is a variant of the first one, which is adjusted to the K K s-wave scattering length recently determined in lattice QCD simulations. The position and width of the (K) over bar (K) over bar N quasibound state is evaluated in two ways: (i) by a direct pole search in the complex energy plane and (ii) using an "inverse determinant" method, where one needs to calculate the determinant of the AGS system of equations only for real energies. Aquasibound state is found with binding energy B ((K) over bar (K) over bar N) = 12-26 MeV and width Gamma((K$) over bar (K) over bar N) (=) 61-102 MeV, which could correspond to the experimentally observed Xi (1950) state.
Trvalý link: http://hdl.handle.net/11104/0251805