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A new algorithm for identifying the flavour of B0s mesons at LHCb

  • Author(s): Aaij, R;
  • Abellán Beteta, C;
  • Adeva, B;
  • Adinolfi, M;
  • Affolder, A;
  • Ajaltouni, Z;
  • Akar, S;
  • Albrecht, J;
  • Alessio, F;
  • Alexander, M;
  • Ali, S;
  • Alkhazov, G;
  • Alvarez Cartelle, P;
  • Alves, AA;
  • Amato, S;
  • Amerio, S;
  • Amhis, Y;
  • An, L;
  • Anderlini, L;
  • Andreassi, G;
  • Andreotti, M;
  • Andrews, JE;
  • Appleby, RB;
  • Aquines Gutierrez, O;
  • Archilli, F;
  • D'Argent, P;
  • Artamonov, A;
  • Artuso, M;
  • Aslanides, E;
  • Auriemma, G;
  • Baalouch, M;
  • Bachmann, S;
  • Back, JJ;
  • Badalov, A;
  • Baesso, C;
  • Baldini, W;
  • Barlow, RJ;
  • Barschel, C;
  • Barsuk, S;
  • Barter, W;
  • Batozskaya, V;
  • Battista, V;
  • Bay, A;
  • Beaucourt, L;
  • Beddow, J;
  • Bedeschi, F;
  • Bediaga, I;
  • Bel, LJ;
  • Bellee, V;
  • Belloli, N;
  • Belyaev, I;
  • Ben-Haim, E;
  • Bencivenni, G;
  • Benson, S;
  • Benton, J;
  • Berezhnoy, A;
  • Bernet, R;
  • Bertolin, A;
  • Betti, F;
  • Bettler, MO;
  • Van Beuzekom, M;
  • Bifani, S;
  • Billoir, P;
  • Bird, T;
  • Birnkraut, A;
  • Bizzeti, A;
  • Blake, T;
  • Blanc, F;
  • Blouw, J;
  • Blusk, S;
  • Bocci, V;
  • Bondar, A;
  • Bondar, N;
  • Bonivento, W;
  • Borgheresi, A;
  • Borghi, S;
  • Borisyak, M;
  • Borsato, M;
  • Bowcock, TJV;
  • Bowen, E;
  • Bozzi, C;
  • Braun, S;
  • Britsch, M;
  • Britton, T;
  • Brodzicka, J;
  • Brook, NH;
  • Buchanan, E;
  • Burr, C;
  • Bursche, A;
  • Buytaert, J;
  • Cadeddu, S;
  • Calabrese, R;
  • Calvi, M;
  • Calvo Gomez, M;
  • Campana, P;
  • Campora Perez, D;
  • Capriotti, L;
  • Carbone, A;
  • Carboni, G;
  • Cardinale, R
  • et al.

Published Web Location

http://doi.org/10.1088/1748-0221/11/05/P05010
No data is associated with this publication.
Abstract

A new algorithm for the determination of the initial flavour of B0s mesons is presented. The algorithm is based on two neural networks and exploits the b hadron production mechanism at a hadron collider. The first network is trained to select charged kaons produced in association with the B0 s meson. The second network combines the kaon charges to assign the B0 s flavour and estimates the probability of a wrong assignment. The algorithm is calibrated using data corresponding to an integrated luminosity of 3 fb-1 collected by the LHCb experiment in protonproton collisions at 7 and 8 TeV centre-of-mass energies. The calibration is performed in two ways: by resolving the B0sB0s flavour oscillations in B0s →D-s φ+ decays, and by analysing flavour-specific B∗ s2 (5840)0→ B+K- decays. The tagging power measured in B0s → D-s φ+ decays is found to be (1:80 ± 0:19 (stat) ± 0:18 (syst))%, which is an improvement of about 50% compared to a similar algorithm previously used in the LHCb experiment.

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