Search for the lepton-flavour-violating decays B 0 → K *0 τ ± e ∓

Journal article

A first search at LHCb for the lepton-flavour-violating decays B0 → K*0τ±e∓ is presented. The analysis is performed using a sample of proton-proton collision data, collected with the LHCb detector at a centre-of-mass energy of 13 TeV between 2016 and 2018, corresponding to an integrated luminosity of 5.4 fb−1. No significant signal is observed, and upper limits on the branching fractions are determined to be BB0→K∗0τ−e+<5.97.1×10−6 and BB0→K∗0τ+e−<4.95.9×10−6 at the 90% (95%) confidence level. These results correspond to the current most stringent upper limits for b → sτl transitions.

Authors: Aaij, R; Abdelmotteleb, ASW; Abellan Beteta, C; Abudinén, F; Ackernley, T

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Springer
• Journal: Journal of High Energy Physics
• Volume: 2025
• Issue: 11
• Article number: 172
• Publication date: 2025-11-26
• Acceptance date: 2025-10-24
• DOI: 10.1007/jhep11(2025)172
• EISSN: 1029-8479
• ISSN: 1126-6708
• Language: English
• Keywords: Beyond Standard Model; Rare Decay; Hadron-Hadron Scattering; B Physics