Three body resonances in two meson one baryon systems

por Kanchan Khemchandani (Universitat de Valencia)

viernes 2 mar. 2007 12:00 → 13:00 Europe/Madrid

Sala Seminarios (Dpto. de Física Teórica (UVEG))

We report four $\Sigma$'s (1480, 1560, 1620 and 1660 MeV) and two $\Lambda$'s (1600 and 1810 MeV) with $J^P= 1/2^+$, which are all the $\Lambda$'s in the PDG below 1810 MeV and all the $\Sigma$'s below 1750 MeV, as dynamically generated resonances in the $\pi \bar{K} N$ system and its coupled channels. We solve Faddeev equations in the coupled channel approach taking twenty two of them into account and assuming correlations in the subsystem of $\bar{K} N$ and its two body coupled channels. The invariant mass of this correlated pair and that of the three particles is varied and the squared three body $T$-matrix is plotted as a function of these two variables. We find three dimensional peaks in these plots at the energies very close to the above mentioned resonances. The input two-body $t$-matrices for meson-meson and meson-baryon interactions have been obtained by solving the Bethe-Salpeter equations with Chiral Lagrangians.