K ¯+N →K +Ξ reaction and S =1 hyperon resonances
Abstract
The K ¯+N →K +Ξ reaction is studied for centerofmomentum energies ranging from threshold to 3 GeV in an effective Lagrangian approach that includes the hyperon s  and u channel contributions as well as a phenomenological contact amplitude. The latter accounts for the rescattering term in the scattering equation and possible shortrange dynamics not included explicitly in the model. Existing data are well reproduced and three abovethethreshold resonances were found to be required to describe the data, namely, the Λ (1890 ) , Σ (2030 ) , and Σ (2250 ) . For the latter resonance we have assumed the spinparity of J^{P}=5 /2^{} and a mass of 2265 MeV. The Σ (2030 ) resonance is crucial in achieving a good reproduction of not only the measured total and differential cross sections but also the recoil polarization asymmetry. More precise data are required before a more definitive statement can be made about the other two resonances, in particular, about the Σ (2250 ) resonance that is introduced to describe a small bump structure observed in the total cross section of K^{}+p →K^{+}+Ξ^{} . The present analysis also reveals a peculiar behavior of the total crosssection data in the threshold energy region in K^{}+p →K^{+}+Ξ^{} , where the P and D waves dominate instead of the usual S wave. Predictions for the targetrecoil asymmetries of the K ¯+N →K +Ξ reaction are also presented.
 Publication:

Physical Review C
 Pub Date:
 June 2015
 DOI:
 10.1103/PhysRevC.91.065208
 arXiv:
 arXiv:1503.00845
 Bibcode:
 2015PhRvC..91f5208J
 Keywords:

 13.75.Jz;
 13.60.Rj;
 13.88.+e;
 14.20.Jn;
 Kaonbaryon interactions;
 Baryon production;
 Polarization in interactions and scattering;
 Hyperons;
 Nuclear Theory;
 High Energy Physics  Phenomenology
 EPrint:
 19 pages, REVTeX, 12 figures, revised version