$S=-1$ meson-baryon interaction and the role of isospin filtering processes

A study of the meson-baryon interaction in the $S=-1$ sector is performed, employing a chiral SU(3) lagrangian up to next-to-leading order (NLO) and implementing unitarization in coupled channels. The model is constrained by a large set of experimental data, paying a especial attention to processes that are sensitive to the NLO contributions, such as the $K^- p\to K^+\Xi^-, K^0\Xi^0$ reactions. The consideration of additional cross sections in single isospin channels, $K^{-}p\to \eta \mathrm{\Lambda },\eta \mathrm{\Sigma }$, has been found to provide more homogeneous and reliable values of the low-energy constants, the stability of which has also been tested by the inclusion of explicit resonant terms. Predictions for new isospin filtering processes, like the $I=1$ $K^0_L p \to K^+ \Xi^0$reactionthatcouldbemeasuredattheproposedsecondary$K^0_L$beamatJlab,ortheweakdecayofthe$\Lambda_b$intoa$J/\Psi$ and different meson-baryon pairs in $I=0$, available at LHCb, are presented. The measurement of such reactions would put valuable constraints on the chiral models describing the $S=-1$ meson-baryon interaction.