Speaker
Description
Using proton-proton collision data corresponding to an integrated luminosity of about $140~\mathrm{fb}^{-1}$ collected by the CMS experiment at $\sqrt{s}= 13~\mathrm{TeV}$ in $2016-2018$, the $\Lambda^{0}_{\mathrm{b}} \to \mathrm{J}/{\psi}\,\Xi^{-}\,\mathrm{K}^{+}$ decay is observed for the first time with a significance exceeding 5 standard deviations. The relative branching fraction, with respect to the $\Lambda^{0}_{\mathrm{b}} \to \psi(\mathrm{2S})\,\Lambda$ decay, is measured and also reported.
Multibody decays of beauty hadrons present a rich laboratory to search for intermediate resonances in the decay products. In the case when decay products contain a charmonium state, such intermediate resonances could decay into a charmonium meson and a hadron, which could be a manifestation of an exotic quark content. Investigation of channels with baryons in the decay products, such as $\Xi^{-}$ and $\Omega^{-}$, could unveil the existence of doubly or triply strange pentaquarks. And the obtained results are important for understanding the strong interaction processes in hadronic decays of beauty baryons and the possible formation of exotic states.
