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arXiv · 2409.03009

Measurement of $CP$ violation in ${B^0}\rightarrow{D^{+}D^{-}}$ and ${B^{0}_{s}}\rightarrow{D^{+}_{s}D^{-}_{s}}$ decays

Abstract

A time-dependent, flavour-tagged measurement of $CP$ violation is performed with ${B^0}\rightarrow{D^{+}D^{-}}$ and ${B^{0}_{s}}\rightarrow{D^{+}_{s}D^{-}_{s}}$ decays, using data collected by the LHCb detector in proton-proton collisions at a centre-of-mass energy of 13 TeV corresponding to an integrated luminosity of 6 fb$^{-1}$. In ${B^0}\rightarrow{D^{+}D^{-}}$ decays the $CP$-violation parameters are measured to be \begin{align} S_{D^{+}D^{-}} & = -0.552 \pm 0.100\,\text{(stat)} \pm 0.010\,\text{(syst)}, \nonumber \newline C_{D^{+}D^{-}} & = \phantom{-}0.128 \pm0.103\,\text{(stat)} \pm 0.010\,\text{(syst)}. \nonumber \end{align} In $B^{0}_{s} \rightarrow D^{+}_{s}D^{-}_{s}$ decays the $CP$-violating parameter formulation in terms of $ϕ_{s}$ and $|λ|$ results in \begin{align} ϕ_{s} & = -0.086 \pm 0.106 \,\text{(stat)} \pm 0.028\,\text{(syst)} \,\text{rad}, \nonumber \newline |λ_{D^{+}_{s}D^{-}_{s}}| & = \phantom{-}1.145 \pm 0.126\,\text{(stat)} \pm 0.031\,\text{(syst)}. \nonumber \end{align} These results represent the most precise single measurement of the $CP$-violation parameters in their respective channels. For the first time in a single measurement, $CP$ symmetry is observed to be violated in ${B^0}\rightarrow{D^{+}D^{-}}$ decays with a significance exceeding six standard deviations.

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BibTeXRIS

LHCb collaboration, R. Aaij, A. S. W. Abdelmotteleb, C. Abellan Beteta, F. Abudinén, T. Ackernley, A. A. Adefisoye, B. Adeva, M. Adinolfi, P. Adlarson, C. Agapopoulou, C. A. Aidala, Z. Ajaltouni, S. Akar, K. Akiba, P. Albicocco, J. Albrecht, F. Alessio, M. Alexander, Z. Aliouche, P. Alvarez Cartelle, R. Amalric, S. Amato, J. L. Amey, Y. Amhis, L. An, L. Anderlini, M. Andersson, A. Andreianov, P. Andreola, M. Andreotti, D. Andreou, A. Anelli, D. Ao, F. Archilli, M. Argenton, S. Arguedas Cuendis, A. Artamonov, M. Artuso, E. Aslanides, R. Ataíde Da Silva, M. Atzeni, B. Audurier, D. Bacher, I. Bachiller Perea, S. Bachmann, M. Bachmayer, J. J. Back, P. Baladron Rodriguez, V. Balagura, W. Baldini, L. Balzani, H. Bao, J. Baptista de Souza Leite, C. Barbero Pretel, M. Barbetti, I. R. Barbosa, R. J. Barlow, M. Barnyakov, S. Barsuk, W. Barter, M. Bartolini, J. Bartz, J. M. Basels, S. Bashir, G. Bassi, B. Batsukh, P. B. Battista, A. Bay, A. Beck, M. Becker, F. Bedeschi, I. B. Bediaga, N. A. Behling, S. Belin, V. Bellee, K. Belous, I. Belov, I. Belyaev, G. Benane, G. Bencivenni, E. Ben-Haim, A. Berezhnoy, R. Bernet, S. Bernet Andres, A. Bertolin, C. Betancourt, F. Betti, J. Bex, Ia. Bezshyiko, J. Bhom, M. S. Bieker, N. V. Biesuz, P. Billoir, A. Biolchini, M. Birch, F. C. R. Bishop, A. Bitadze, A. Bizzeti, T. Blake. 2025-01-16. Measurement of $CP$ violation in ${B^0}\rightarrow{D^{+}D^{-}}$ and ${B^{0}_{s}}\rightarrow{D^{+}_{s}D^{-}_{s}}$ decays. https://doi.org/10.1007/jhep01(2025)061

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