Dalitz plot analysis of B-0 -> (D)over-bar(0)pi(+)pi(-) decays

The resonant substructures of B-0 --> (D) overbar (0) pi(+) pi(-) decays are studied with the Dalitz plottechnique. In this study a data sample corresponding to an integrated luminosity of 3.0 fb(-1) of pp collisions collected by the LHCb detector is used. The branching fractionof the B-0 --> (D) overbar (0) pi(+) pi(-) decay in the region m((D) overbar (0) pi(+/-)) > 2.1 GeV/c(2) is measured to be (8.46 +/- 0.14 +/- 0.29 +/- 0.40) x 10(-4), where the first uncertainty is statistical, the second is systematic and the last arises from the normalization channel B-0 --> D*(2010)(-) pi(+). The pi(+) pi(-) S-wave components are modeled with the isobar and K-matrix formalisms. Results of the Dalitz plotanalyses using both models are presented. A resonant structure at m((D) overbar (0) pi(-)) approximate to 2.8 GeV/c(2) is confirmed and its spin-parity is determined for the first time as J(P) = 3(-). The branching fraction, mass and width of this structure are determined together with those of the D-0*(2400)(-) and D-2*(2460)(-) resonances. The branching fractionsof other B-0 --> (D) overbar (0)h(0) decay components with h(0) --> pi(+) pi(-) also reported. Many of these branching fractionmeasurements are the most precise to date. The first observation of the decays B0 --> (D) overbar (0)f(0)(500), B-0 --> (D) overbar (0)f(0)(980), B-0 --> (D) overbar (0)rho(1450), B-0 --> D-3(*)(2760)(-) pi(+) and the first evidence of B-0 --> (D) overbar (0)f(0)(2020) are presented.