Measurement of the CP asymmetry in D → π π0 decays at Belle II

I Adachi; L Aggarwal; H Ahmed; H Aihara; N Akopov; S Alghamdi; M Alhakami; A Aloisio; K Amos; M Angelsmark; N Anh Ky; C Antonioli; DM Asner; H Atmacan; V Aushev; M Aversano; R Ayad; V Babu; H Bae; NK Baghel; P Bambade; S Banerjee; S Bansal; M Barrett; M Bartl; J Baudot; A Baur; A Beaubien; F Becherer; J Becker; JV Bennett; FU Bernlochner; V Bertacchi; M Bertemes; E Bertholet; M Bessner; S Bettarini; V Bhardwaj; B Bhuyan; F Bianchi; D Biswas; A Bobrov; D Bodrov; A Bondar; G Bonvicini; J Borah; A Boschetti; A Bozek; M Bračko; P Branchini; RA Briere; TE Browder; A Budano; S Bussino; Q Campagna; M Campajola; L Cao; G Casarosa; C Cecchi; MC Chang; P Cheema; L Chen; BG Cheon; K Chilikin; J Chin; K Chirapatpimol; HE Cho; K Cho; SJ Cho; SK Choi; S Choudhury; I Consigny; L Corona; JX Cui; S Das; E De La Cruz-Burelo; S A. De La Motte; G De Pietro; R de Sangro; M Destefanis; A Di Canto; Z Doležal; ID Jiménez; TV Dong; X Dong; M Dorigo; K Dugic; G Dujany; P Ecker; D Epifanov; J Eppelt; R Farkas; P Feichtinger; T Ferber; T Fillinger; C Finck; G Finocchiaro; F Forti; A Frey; BG Fulsom

Journal article

Measurement of the CP asymmetry in D → π π0 decays at Belle II

I Adachi, L Aggarwal, H Ahmed, H Aihara, N Akopov, S Alghamdi, M Alhakami, A Aloisio, K Amos, M Angelsmark, N Anh Ky, C Antonioli, DM Asner, H Atmacan, V Aushev, M Aversano, R Ayad, V Babu, H Bae, NK Baghel Show all

Physical Review D | American Physical Society (APS) | Published : 2025

DOI: 10.1103/3kqk-ldm4

Abstract

We measure the CP asymmetry in D+ → π+π0 decays reconstructed in e+e− collisions at the Belle II experiment using a dataset corresponding to an integrated luminosity of 428 fb−1. A control sample of (Formula Presented) decays is used to correct for detection and production asymmetries. The result ACP(D+ → π+π0) = (−1.8 ± 0.9 ± 0.1)%, where the first uncertainty is statistical and the second systematic, is the most precise determination to date. It agrees with the prediction of CP symmetry from the standard model and with results of previous measurements.