Search for a dark leptophilic scalar produced in association with τ τ- pair in e e- annihilation at center-of-mass energies near 10.58 GeV

D Biswas; S Banerjee; I Adachi; H Aihara; DM Asner; T Aushev; R Ayad; V Babu; P Behera; J Bennett; M Bessner; V Bhardwaj; B Bhuyan; T Bilka; D Bodrov; J Borah; A Bozek; M Bračko; P Branchini; TE Browder; A Budano; M Campajola; D Červenkov; MC Chang; P Chang; BG Cheon; K Chilikin; HE Cho; K Cho; SK Choi; Y Choi; S Choudhury; D Cinabro; S Das; G De Nardo; G De Pietro; R Dhamija; F Di Capua; J Dingfelder; Z DoleŽal; TV Dong; S Dubey; P Ecker; D Epifanov; T Ferber; BG Fulsom; V Gaur; A Garmash; A Giri; P Goldenzweig; E Graziani; Y Guan; K Gudkova; C Hadjivasiliou; K Hayasaka; H Hayashii; S Hazra; MT Hedges; D Herrmann; M Hernández Villanueva; WS Hou; CL Hsu; K Inami; G Inguglia; N Ipsita; A Ishikawa; R Itoh; M Iwasaki; WW Jacobs; QP Ji; S Jia; Y Jin; KK Joo; AB Kaliyar; C Kiesling; CH Kim; DY Kim; KH Kim; YJ Kim; YK Kim; P Kodyš; T Konno; A Korobov; S Korpar; P KriŽan; P Krokovny; M Kumar; K Kumara; YJ Kwon; YT Lai; M Laurenza; SC Lee; D Levit; J Li; LK Li; Y Li; L Li Gioi; J Libby; K Lieret; YR Lin

Journal article

Search for a dark leptophilic scalar produced in association with τ τ- pair in e e- annihilation at center-of-mass energies near 10.58 GeV

D Biswas, S Banerjee, I Adachi, H Aihara, DM Asner, T Aushev, R Ayad, V Babu, P Behera, J Bennett, M Bessner, V Bhardwaj, B Bhuyan, T Bilka, D Bodrov, J Borah, A Bozek, M Bračko, P Branchini, TE Browder Show all

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

DOI: 10.1103/PhysRevD.109.032002

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Abstract

A dark leptophilic scalar (φL) is a hypothetical particle that couples only to leptons rather than quarks. We report on a search for φL in the e+e-→τ+τ-φL, φL→ℓ+ℓ-(ℓ=e,μ) process using 626 fb-1 of data collected by the Belle experiment near the ϒ(4S) resonance. We validate the backgrounds with multiple control regions in data, using a novel multiclass multivariate event classifier. In absence of a signal, we quote upper limits at the 90% confidence level on the coupling between φL and leptons. Our bounds, obtained in a blinded approach, are 19% more constraining than the previous limits, averaged over the mass range 0.04≤mφL≤6.5 GeV. We exclude the parameter space below 4 GeV favored by meas..

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