We present a search for the rare flavor-changing neutral-current decay B0→K∗0τ+τ- with data collected by the Belle II experiment at the SuperKEKB electron-positron collider. The analysis uses a 365 fb-1 data sample recorded at the center-of-mass energy of the ϒ(4S) resonance. One of the B mesons produced in the ϒ(4S)→B0B¯0 process is fully reconstructed in a hadronic decay mode, while its companion B meson is required to decay into a K∗0 and two τ leptons of opposite charge. The τ leptons are reconstructed in final states with a single electron, muon, charged pion or charged ρ meson, and additional neutrinos. We set an upper limit on the branching fraction of B(B0→K∗0τ+τ-)<1.8×10-3 at the 90% confidence level, which is the most stringent constraint reported to date.

Adachi, I., Adamczyk, K., Aggarwal, L., Ahmed, H., Aihara, H., Akopov, N., et al. (2025). Search for B0 →k∗0τ+τ- Decays at the Belle II Experiment. PHYSICAL REVIEW LETTERS, 135(15), 151801-1-151801-8 [10.1103/v1q3-9dy8].

Search for B0 →k∗0τ+τ- Decays at the Belle II Experiment

Di Canto A.;
2025

Abstract

We present a search for the rare flavor-changing neutral-current decay B0→K∗0τ+τ- with data collected by the Belle II experiment at the SuperKEKB electron-positron collider. The analysis uses a 365 fb-1 data sample recorded at the center-of-mass energy of the ϒ(4S) resonance. One of the B mesons produced in the ϒ(4S)→B0B¯0 process is fully reconstructed in a hadronic decay mode, while its companion B meson is required to decay into a K∗0 and two τ leptons of opposite charge. The τ leptons are reconstructed in final states with a single electron, muon, charged pion or charged ρ meson, and additional neutrinos. We set an upper limit on the branching fraction of B(B0→K∗0τ+τ-)<1.8×10-3 at the 90% confidence level, which is the most stringent constraint reported to date.
2025
Adachi, I., Adamczyk, K., Aggarwal, L., Ahmed, H., Aihara, H., Akopov, N., et al. (2025). Search for B0 →k∗0τ+τ- Decays at the Belle II Experiment. PHYSICAL REVIEW LETTERS, 135(15), 151801-1-151801-8 [10.1103/v1q3-9dy8].
Adachi, I.; Adamczyk, K.; Aggarwal, L.; Ahmed, H.; Aihara, H.; Akopov, N.; Alhakami, M.; Aloisio, A.; Althubiti, N.; Angelsmark, M.; Anh Ky, N.; Asner...espandi
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/1084153
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