# Observation of the decay Lambda(0)(b) -> Lambda(+)(c)p(p)over-bar pi(-)

Aaij, R, Adeva, B, Adinolfi, M, Ajaltouni, Z, Akar, S, Albicocco, R, Albrecht, J, Alessio, F, Alexander, M, Albero, A Alfonso
et al (show 781 more authors) (2018) Observation of the decay Lambda(0)(b) -> Lambda(+)(c)p(p)over-bar pi(-). PHYSICS LETTERS B, 784. pp. 101-111.

The decay $\Lambda_b^0 \to \Lambda_c^+ p \overline{p} \pi^-$ is observed using $pp$ collision data collected with the LHCb detector at centre-of-mass energies of $\sqrt{s}=$ 7 and 8 TeV, corresponding to an integrated luminosity of 3 $fb^{-1}$. The ratio of branching fractions between $\Lambda_b^0 \to \Lambda_c^+ p \overline{p} \pi^-$ and $\Lambda_b^0 \to \Lambda_c^+ \pi^-$ decays is measured to be \begin{equation*} \frac{\mathcal{B}(\Lambda_b^0 \to \Lambda_c^+ p \overline{p}\pi^-)}{\mathcal{B}(\Lambda_b^0 \to \Lambda_c^+ \pi^-)} = 0.0540 \pm 0.0023 \pm 0.0032. \end{equation*} Two resonant structures are observed in the $\Lambda_c^+ \pi^-$ mass spectrum of the ${\Lambda_b^0 \to \Lambda_c^+ p\overline{p} \pi^-}$ decays, corresponding to the $\Sigma_c(2455)^0$ and $\Sigma_c^{*}(2520)^0$ states. The ratios of branching fractions with respect to the decay $\Lambda_b^0 \to \Lambda_c^+ p \overline{p} \pi^-$ are \begin{align*} \frac{\mathcal{B}(\Lambda_b^0 \to \Sigma_c^0 p\overline{p})\times\mathcal{B}(\Sigma_c^0\to \Lambda_c^+ \pi^-)}{\mathcal{B}(\Lambda_b^0 \to \Lambda_c^+ p \overline{p}\pi^-)} = 0.089\pm0.015\pm0.006, \frac{\mathcal{B}(\Lambda_b^0 \to \Sigma_c^{*0} p\overline{p})\times\mathcal{B}(\Sigma_c^{*0}\to \Lambda_c^+ \pi^-)}{\mathcal{B}(\Lambda_b^0 \to \Lambda_c^+ p \overline{p}\pi^-)} = 0.119\pm0.020\pm0.014. \end{align*} In all of the above results, the first uncertainty is statistical and the second is systematic. The phase space is also examined for the presence of dibaryon resonances. No evidence for such resonances is found.