Physics Letters B 784 (2018) 101–111Contents lists available at ScienceDirectPhysics Letters Bwww.elsevier.com/locate/physletbObservation of the decay Λ0b→ Λ+cppπ−

The decay Lambda(0)(b) -u003e Lambda(+)(c)p (p) over bar pi(-) is observed using pp collision data collected with the LHCb detector at centre-of-mass energies of root s = 7 and 8 Tev, corresponding to an integrated luminosity of 3 fb(-1). The ratio of branching fractions between Lambda(0)(b) -u003e Lambda(+)(c)p (p) over bar pi(-) and Lambda(0)(b) -u003e Lambda(+)(c)pi(-) decays is measured to be B(Lambda(0)(b) -u003e Lambda(+)(c)p (p) over bar pi(-))/B(Lambda(0)(b) -u003e Lambda(+)(c)pi(-) = 0.0540 +/- 0.0023 +/- 0.0032. Two resonant structures are observed in the Lambda(+)(c)pi(-) mass spectrum of the Lambda(0)(b) -u003e Lambda(+)(c)pp pi(-) decays, corresponding to the Xc(2455) and X (2520) states. The ratios of branching fractions with respect to the decay Lambda(0)(b) -u003e Lambda(+)(c)p (p) over bar pi(-) are B(Lambda(0)(b) -u003e Sigma(0)(c)p (p) over bar x B(Sigma(0)(b) -u003e Lambda(+)(c)pi(-))/B(Lambda(0)(b) -u003e Lambda(+)(c)p (p) over bar pi(-)) = 0.089 +/- 0.015 +/- 0.006, B(Lambda(0)(b) -u003e Sigma(c)*(0)p (p) over bar x B(Sigma(c)*(0) -u003e Lambda(+)(c)pi(-))/B(Lambda(0)(b) -u003e Lambda(+)(c)p (p) over bar pi(-)) = 0.119 +/- 0.020 +/- 0.014. 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. (C) 2018 The Author(s). Published by Elsevier B.V.