Study of the decay B[over ¯]^{0}→Λ_{c}^{+}p[over ¯]π^{+}π^{-} and its intermediate states

We study the decay B¯0→Λc+p¯π+π-, reconstructing the Λc+ baryon in the pK-π+ mode, using a data sample of 467×106 BB¯ pairs collected with the BABAR detector at the PEP-II storage rings at SLAC. We measure branching fractions for decays with intermediate Σc baryons to be B[B¯0→Σc(2455)++p¯π-]=(21.3±1.0±1.0±5.5)×10-5, B[B¯0→Σc(2520)++p¯π-]=(11.5±1.0±0.5±3.0)×10-5, B[B¯0→Σc(2455)0p¯π+]=(9.1±0.7±0.4±2.4)×10-5, and B[B¯0→Σc(2520)0p¯π+]=(2.2±0.7±0.1±0.6)×10-5, where the uncertainties are statistical, systematic, and due to the uncertainty on the Λc+→pK-π+ branching fraction, respectively. For decays without Σc(2455) or Σc(2520) resonances, we measure B[B¯0→Λc+p¯π+π-]non-Σc=(79±4±4±20)×10-5. The total branching fraction is determined to be B[B¯0→Λc+p¯π+π-]total=(123±5±7±32)×10-5. We examine multibody mass combinations in the resonant three-particle Σcp¯π final states and in the four-particle Λc+p¯π+π- final state, and observe different characteristics for the p¯π combination in neutral versus doubly charged Σc decays.