A dynamical coupled-channel formalism for processes $\\pi N \\to KY$ and $\\gamma N \\to KY$ is
presented which provides a comprehensive investigation of recent data on the $\\gamma p \\to K^+ \\Lambda$ reaction.
The non-resonant interactions within the subspace $KY\\oplus\\pi N$ are derived from effective Lagrangians,
using a unitary transformation method. The calculations of photoproduction amplitudes are simplified by casting
the coupled-channel equations into a form such that the empirical $\\gamma N \\to \\pi N$ amplitudes are input
and only the parameters associated with the $KY$ channel are determined by performing $\\chi^2$-fits to all of
the available data for $\\pi^- p \\to K^\\circ\\Lambda, K^\\circ\\Sigma^\\circ$ and $\\gamma p \\to K^+\\Lambda$.
Good agreement between our models and those data are obtained. In the fits to $\\pi N \\to KY$ channels, most of
the parameters are constrained within $\\pm 20%$ of the values given by the Particle Data Group and/or quark model
predictions, while for $\\gamma p \\to K^+ \\Lambda$ parameters, ranges compatible with broken $SU(6)\\otimes O(3)$
symmetry are imposed. The main reaction mechanisms in $K^+ \\Lambda$ photoproduction are singled out and issues
related to newly suggested resonances $S_{11}$, $P_{13}$, and $D_{13}$ are studied. Results illustrating the
importance of using a coupled-channel treatment are reported. Meson cloud effects on the $\\gamma N \\to N^*$ transitions
are also discussed.
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