Multistrange Meson-Baryon Dynamics and Resonance Generation

作者：Khemchandani K P^*; Martinez Torres A; Hosaka A; Nagahiro H; Navarra F S; Nielsen M

来源：Few-Body Systems, 2018, 59(3): UNSP 29.

DOI：10.1007/s00601-018-1338-2

In this talk I review our recent studies on meson-baryon systems with strangeness -1 and -2. The motivation of our works is to find resonances generated as a consequence of coupled channel meson-baryon interactions. The coupled channels are all meson-baryon systems formed by combining a pseudoscalar or a vector meson with an octet baryon such that the system has the strange quantum number equal to -1 or -2. The lowest order meson-baryon interaction amplitudes are obtained from Lagrangians based on the chiral and the hidden local symmetries related to the vector mesons working as the gauge bosons. These lowest order amplitudes are used as an input to solve the Bethe-Salpeter equation and a search for poles is made in the resulting amplitudes, in the complex plane. In case of systems with strangeness -1, we find evidence for the existence of some hyperons such as: Lambda(2000), Sigma(1750), Sigma(1940), Sigma(2000). More recently, in the study of strangeness -2 systems we have found two narrow resonances which can be related to Xi(1690) and Xi(2120). In this latter work, we have obtained the lowest order amplitudes relativistically as well as in the nonrelativistic approximation to solve the scattering equations. We find that the existence of the poles in the complex plane does not get affected by the computation of the scattering equation with the lowest order amplitudes obtained in the nonrelativistic approximation.

• 出版日期2018-5