A new algorithm for identifying the flavour of B<sub>s</sub><SUP>0</SUP> mesons at LHCb

Aaij, R, Beteta, C Abellan, Adeva, B, Adinolfi, M, Affolder, A, Ajaltouni, Z, Akar, S, Albrecht, J, Alessio, F, Alexander, M
et al (show 725 more authors) (2016) A new algorithm for identifying the flavour of B<sub>s</sub><SUP>0</SUP> mesons at LHCb. JOURNAL OF INSTRUMENTATION, 11 (05). P05010-.

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A new algorithm for the determination of the initial flavour of $B_s^0$ 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 $B_s^0$ meson. The second network combines the kaon charges to assign the $B_s^0$ 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 proton-proton collisions at 7 and 8 TeV centre-of-mass energies. The calibration is performed in two ways: by resolving the $B_s^0$-$\bar{B}_s^0$ flavour oscillations in $B_s^0 \to D_s^- \pi^+$ decays, and by analysing flavour-specific $B_{s 2}^{*}(5840)^0 \to B^+ K^-$ decays. The tagging power measured in $B_s^0 \to D_s^- \pi^+$ decays is found to be $(1.80 \pm 0.19({\rm stat}) \pm 0.18({\rm syst}))$\%, which is an improvement of about 50\% compared to a similar algorithm previously used in the LHCb experiment.

Item Type: Article
Additional Information: All figures and tables, along with any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-056.html
Uncontrolled Keywords: Analysis and statistical methods, Particle identification methods, Pattern recognition, cluster finding, calibration and fitting methods
Depositing User: Symplectic Admin
Date Deposited: 07 Jun 2016 11:18
Last Modified: 18 Oct 2023 01:22
DOI: 10.1088/1748-0221/11/05/P05010
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3001575