New results on exotic baryon resonances at LHCb

Observation of exotic resonant structures decaying into $J/\psi p$ found in the LHCb experiment is discussed. Examination of the $J/\psi p$ system in $\Lambda^{0}_{b} \to J/\psi K^{-} p$ decays shows two states, each of which must be composed of at least $c \bar{c} uud$ quarks, and are thus consistent with pentaquarks. The significance of each of these resonances is more than 9 standard deviations. Their masses are ($4 380 \pm 8 \pm 29$) MeV and ($4 449.8 \pm 1.7 \pm 2.5$) MeV, and their corresponding widths are ($205 \pm 18 \pm 86$) MeV, and ($39 \pm 5 \pm 19$) MeV. The preferred $J^{P}$ assignments are of opposite parity, with one state having spin 3/2 and the other 5/2.