We present GFlaT, a new algorithm that uses a graph-neural-network to determine the flavor of neutral B mesons produced in ϒ(4S) decays. It improves previous algorithms by using the information from all charged final-state particles and the relations between them. We evaluate its performance using B decays to flavor-specific hadronic final states reconstructed in a 362 fb−1 sample of electron-positron collisions collected at the ϒ(4S) resonance with the Belle II detector at the SuperKEKB collider. We achieve an effective tagging efficiency of (37.40 +/- 0.43 +/- 0.36%), where the first uncertainty is statistical and the second systematic, which is 18% better than the previous Belle II algorithm. Demonstrating the algorithm, we use B0 → J->ψ K0S decays to measure the mixing-induced and direct CP violation parameters, S = (0.724 +/- 0.035 +/- 0.009) and C = (−0.035 +/- 0.026 +/- 0.029).

Adachi, I., Aggarwal, L., Ahmed, H., Aihara, H., Akopov, N., Aloisio, A., et al. (2024). New graph-neural-network flavor tagger for Belle II and measurement of sin 2ϕ1 in B0 → J/ψKS0 decays. PHYSICAL REVIEW D, 110(1), 012001-1-012001-14 [10.1103/physrevd.110.012001].

New graph-neural-network flavor tagger for Belle II and measurement of sin 2ϕ1 in B0 → J/ψKS0 decays

Branchini, P.
Membro del Collaboration Group
;
Budano, A.
Membro del Collaboration Group
;
Bussino, S.
Membro del Collaboration Group
;
De Pietro, G.
Membro del Collaboration Group
;
Laurenza, M.
Membro del Collaboration Group
;
Martellini, C.
Membro del Collaboration Group
;
Martini, A.
Membro del Collaboration Group
;
2024-01-01

Abstract

We present GFlaT, a new algorithm that uses a graph-neural-network to determine the flavor of neutral B mesons produced in ϒ(4S) decays. It improves previous algorithms by using the information from all charged final-state particles and the relations between them. We evaluate its performance using B decays to flavor-specific hadronic final states reconstructed in a 362 fb−1 sample of electron-positron collisions collected at the ϒ(4S) resonance with the Belle II detector at the SuperKEKB collider. We achieve an effective tagging efficiency of (37.40 +/- 0.43 +/- 0.36%), where the first uncertainty is statistical and the second systematic, which is 18% better than the previous Belle II algorithm. Demonstrating the algorithm, we use B0 → J->ψ K0S decays to measure the mixing-induced and direct CP violation parameters, S = (0.724 +/- 0.035 +/- 0.009) and C = (−0.035 +/- 0.026 +/- 0.029).
2024
Adachi, I., Aggarwal, L., Ahmed, H., Aihara, H., Akopov, N., Aloisio, A., et al. (2024). New graph-neural-network flavor tagger for Belle II and measurement of sin 2ϕ1 in B0 → J/ψKS0 decays. PHYSICAL REVIEW D, 110(1), 012001-1-012001-14 [10.1103/physrevd.110.012001].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11590/480748
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