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arXiv · 1709.01156

First observation of the rare purely baryonic decay $B^0 \to p \bar{p}$

LHCb collaboration·R. Aaij·B. Adeva·M. Adinolfi·Z. Ajaltouni·S. Akar·J. Albrecht·F. Alessio·M. Alexander·A. Alfonso Albero·S. Ali·G. Alkhazov·P. Alvarez Cartelle·A. A. Alves Jr·S. Amato·S. Amerio·Y. Amhis·L. An·L. Anderlini·G. Andreassi·M. Andreotti·J. E. Andrews·R. B. Appleby·F. Archilli·P. d'Argent·J. Arnau Romeu·A. Artamonov·M. Artuso·E. Aslanides·G. Auriemma·M. Baalouch·I. Babuschkin·S. Bachmann·J. J. Back·A. Badalov·C. Baesso·S. Baker·V. Balagura·W. Baldini·A. Baranov·R. J. Barlow·C. Barschel·S. Barsuk·W. Barter·F. Baryshnikov·V. Batozskaya·V. Battista·A. Bay·L. Beaucourt·J. Beddow·F. Bedeschi·I. Bediaga·A. Beiter·L. J. Bel·N. Beliy·V. Bellee·N. Belloli·K. Belous·I. Belyaev·E. Ben-Haim·G. Bencivenni·S. Benson·S. Beranek·A. Berezhnoy·R. Bernet·D. Berninghoff·E. Bertholet·A. Bertolin·C. Betancourt·F. Betti·M. -O. Bettler·M. van Beuzekom·Ia. Bezshyiko·S. Bifani·P. Billoir·A. Birnkraut·A. Bitadze·A. Bizzeti·M. Bjørn·T. Blake·F. Blanc·J. Blouw·S. Blusk·V. Bocci·T. Boettcher·A. Bondar·N. Bondar·W. Bonivento·I. Bordyuzhin·A. Borgheresi·S. Borghi·M. Borisyak·M. Borsato·F. Bossu·M. Boubdir·T. J. V. Bowcock·E. Bowen·C. Bozzi·S. Braun·T. Britton
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Abstract

The first observation of the decay of a $B^0$ meson to a purely baryonic final state, $B^0 \to p \bar{p}$, is reported. The proton-proton collision data sample used was collected with the LHCb experiment at center-of-mass energies of 7 and 8 TeV and corresponds to an integrated luminosity of 3.0 fb$^{-1}$. The branching fraction is determined to be $${\cal B}(B^0 \to p \bar{p}) = ( 1.25 \pm 0.27 \pm 0.18 ) \times 10^{-8} ,$$ where the first uncertainty is statistical and the second systematic. The decay mode $B^0 \to p \bar{p}$ is the rarest decay of the $B^0$ meson observed to date. The decay $B_s^0 \to p \bar{p}$ is also investigated. No signal is seen and the upper limit ${\cal B}(B_s^0 \to p \bar{p}) < 1.5 \times 10^{-8}$ at 90% confidence level is set on the branching fraction.

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LHCb collaboration, R. Aaij, B. Adeva, M. Adinolfi, Z. Ajaltouni, S. Akar, J. Albrecht, F. Alessio, M. Alexander, A. Alfonso Albero, S. Ali, G. Alkhazov, P. Alvarez Cartelle, A. A. Alves Jr, S. Amato, S. Amerio, Y. Amhis, L. An, L. Anderlini, G. Andreassi, M. Andreotti, J. E. Andrews, R. B. Appleby, F. Archilli, P. d'Argent, J. Arnau Romeu, A. Artamonov, M. Artuso, E. Aslanides, G. Auriemma, M. Baalouch, I. Babuschkin, S. Bachmann, J. J. Back, A. Badalov, C. Baesso, S. Baker, V. Balagura, W. Baldini, A. Baranov, R. J. Barlow, C. Barschel, S. Barsuk, W. Barter, F. Baryshnikov, V. Batozskaya, V. Battista, A. Bay, L. Beaucourt, J. Beddow, F. Bedeschi, I. Bediaga, A. Beiter, L. J. Bel, N. Beliy, V. Bellee, N. Belloli, K. Belous, I. Belyaev, E. Ben-Haim, G. Bencivenni, S. Benson, S. Beranek, A. Berezhnoy, R. Bernet, D. Berninghoff, E. Bertholet, A. Bertolin, C. Betancourt, F. Betti, M. -O. Bettler, M. van Beuzekom, Ia. Bezshyiko, S. Bifani, P. Billoir, A. Birnkraut, A. Bitadze, A. Bizzeti, M. Bjørn, T. Blake, F. Blanc, J. Blouw, S. Blusk, V. Bocci, T. Boettcher, A. Bondar, N. Bondar, W. Bonivento, I. Bordyuzhin, A. Borgheresi, S. Borghi, M. Borisyak, M. Borsato, F. Bossu, M. Boubdir, T. J. V. Bowcock, E. Bowen, C. Bozzi, S. Braun, T. Britton. 2017-12-06. First observation of the rare purely baryonic decay $B^0 \to p \bar{p}$. https://doi.org/10.1103/physrevlett.119.232001

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