Study of $\Lambda (1405)$ in photoproduction of $K^{\ast }$

Abstract

We investigate the photoproduction of $K^{\ast }$ vector meson for the study of the $\Lambda (1405)$ resonance. The invariant mass distribution of $\pi \Sigma$ shows a different shape from the nominal one, peaking at 1420 MeV. This is considered as a consequence of the double pole structure of $\Lambda (1405)$, predicted in the chiral unitary model. Combined with other reactions, such as ${\pi }^{-}p\to K^0\pi \Sigma$, experimental confirmation of this fact will reveal a novel structure of the $\Lambda (1405)$ state.

Comments: revtex4, 4 pages, 5 figures, 1 table, Invited talk at the YITP workshop on ``Multi-quark Hadrons; Four, Five and More?'', Feb. 17-19, 2004, Kyoto, Japan