Search for the baryon number and lepton number violating decays τ- → Λπ- and τ- → Λ ¯ π- Belle II

I Adachi; L Aggarwal; H Ahmed; H Aihara; N Akopov; A Aloisio; N Althubiti; N Anh Ky; DM Asner; H Atmacan; T Aushev; V Aushev; M Aversano; R Ayad; V Babu; H Bae; S Bahinipati; P Bambade; S Banerjee; S Bansal; M Barrett; J Baudot; A Baur; A Beaubien; F Becherer; J Becker; JV Bennett; FU Bernlochner; V Bertacchi; M Bertemes; E Bertholet; M Bessner; S Bettarini; B Bhuyan; F Bianchi; L Bierwirth; T Bilka; D Biswas; A Bobrov; D Bodrov; J Borah; A Boschetti; A Bozek; P Branchini; TE Browder; A Budano; S Bussino; Q Campagna; M Campajola; G Casarosa; C Cecchi; J Cerasoli; MC Chang; R Cheaib; P Cheema; BG Cheon; K Chilikin; K Chirapatpimol; HE Cho; K Cho; SJ Cho; SK Choi; S Choudhury; J Cochran; L Corona; JX Cui; E De La Cruz-Burelo; SA De La Motte; G De Nardo; G De Pietro; R De Sangro; M Destefanis; S Dey; R Dhamija; A Di Canto; F Di Capua; J Dingfelder; Z DoleŽal; I Domínguez Jiménez; TV Dong; M Dorigo; K Dort; D Dossett; S Dubey; G Dujany; P Ecker; D Epifanov; J Eppelt; P Feichtinger; T Ferber; T Fillinger; C Finck; G Finocchiaro; A Fodor; F Forti; A Frey; BG Fulsom; A Gabrielli; E Ganiev; M Garcia-Hernandez

Journal article

Search for the baryon number and lepton number violating decays τ- → Λπ- and τ- → Λ ¯ π- Belle II

I Adachi, L Aggarwal, H Ahmed, H Aihara, N Akopov, A Aloisio, N Althubiti, N Anh Ky, DM Asner, H Atmacan, T Aushev, V Aushev, M Aversano, R Ayad, V Babu, H Bae, S Bahinipati, P Bambade, S Banerjee, S Bansal Show all

Physical Review D | American Physical Society (APS) | Published : 2024

DOI: 10.1103/PhysRevD.110.112003

Abstract

We present a search for the baryon number B and lepton number L violating decays τ-→Λπ- and τ-→Λ¯π- produced from the e+e-→τ+τ- process, using a 364 fb-1 data sample collected by the Belle II experiment at the SuperKEKB collider. No evidence of signal is found in either decay mode, which have |Δ(B-L)| equal to 2 and 0, respectively. Upper limits at 90% credibility level on the branching fractions of τ-→Λπ- and τ-→Λ¯π- are determined to be 4.7×10-8 and 4.3×10-8, respectively.