# Dalitz plot analysis of $B^0 \to \overline{D}^0 \pi^+\pi^-$ decays

Abstract : The resonant substructures of $B^0 \to \overline{D}^0 \pi^+\pi^-$ decays are studied with the Dalitz plot technique. 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 fraction of the $B^0 \to \overline{D}^0 \pi^+\pi^-$ decay in the region $m(\overline{D}^0\pi^{\pm})>2.1$ GeV$/c^2$ is measured to be $(8.46 \pm 0.14 \pm 0.29 \pm 0.40) \times 10^{-4}$, where the first uncertainty is statistical, the second is systematic and the last arises from the normalisation channel $B^0 \to D^*(2010)^-\pi^+$. The $\pi^+\pi^-$ S-wave components are modelled with the Isobar and K-matrix formalisms. Results of the Dalitz plot analyses using both models are presented. A resonant structure at $m(\overline{D}^0\pi^-) \approx 2.8$ 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 fractions of other $B^0 \to \overline{D}^0 h^0$ decay components with $h^0 \to \pi^+\pi^-$ are also reported. Many of these branching fraction measurements are the most precise to date. The first observation of the decays $B^0 \to \overline{D}^0 f_0(500)$, $B^0 \to \overline{D}^0 f_0(980)$, $B^0 \to \overline{D}^0 \rho(1450)$, $B^0 \to D_3^*(2760)^- \pi^+$ and the first evidence of $B^0 \to \overline{D}^0 f_0(2020)$ are presented.
Type de document :
Article dans une revue
Physical Review D, American Physical Society, 2015, 92, pp.032002. 〈10.1103/PhysRevD.92.032002〉
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http://hal.in2p3.fr/in2p3-01150338
Contributeur : Danielle Cristofol <>
Soumis le : lundi 11 mai 2015 - 09:14:40
Dernière modification le : mardi 13 novembre 2018 - 21:58:08

### Citation

R. Aaij, B. Adeva, M. Adinolfi, A. Affolder, Ziad Ajaltouni, et al.. Dalitz plot analysis of $B^0 \to \overline{D}^0 \pi^+\pi^-$ decays. Physical Review D, American Physical Society, 2015, 92, pp.032002. 〈10.1103/PhysRevD.92.032002〉. 〈in2p3-01150338〉

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