Measurement of the time-integrated CP asymmetry in D0 → K0SK0S decays using opposite-side flavor tagging at Belle and Belle II

I Adachi; Y Ahn; N Akopov; S Alghamdi; M Alhakami; A Aloisio; N Althubiti; K Amos; M Angelsmark; N AnhKy; C Antonioli; DM Asner; H Atmacan; T Aushev; M Aversano; R Ayad; V Babu; H Bae; NK Baghel; S Bahinipati; P Bambade; S Banerjee; 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; B Bhuyan; F Bianchi; T Bilka; D Biswas; A Bobrov; D Bodrov; A Bondar; J Borah; A Boschetti; A Bozek; M Bračko; P Branchini; RA Briere; TE Browder; A Budano; S Bussino; M Campajola; L Cao; G Casarosa; C Cecchi; P Cheema; BG Cheon; K Chilikin; J Chin; K Chirapatpimol; HE Cho; K Cho; SJ Cho; SK Choi; S Choudhury; I Consigny; L Corona; JX Cui; E DeLaCruz-Burelo; SA DeLaMotte; G deMarino; G DePietro; R deSangro; M Destefanis; A DiCanto; J Dingfelder; Z Doležal; I DomínguezJiménez; TV Dong; M Dorigo; G Dujany; P Ecker; D Epifanov; R Farkas; P Feichtinger; T Ferber; T Fillinger; C Finck; G Finocchiaro; A Fodor; F Forti; BG Fulsom; A Gabrielli; A Gale; E Ganiev; M Garcia-Hernandez; R Garg; G Gaudino; V Gaur

Journal article

Measurement of the time-integrated CP asymmetry in D0 → K0SK0S decays using opposite-side flavor tagging at Belle and Belle II

I Adachi, Y Ahn, N Akopov, S Alghamdi, M Alhakami, A Aloisio, N Althubiti, K Amos, M Angelsmark, N AnhKy, C Antonioli, DM Asner, H Atmacan, T Aushev, M Aversano, R Ayad, V Babu, H Bae, NK Baghel, S Bahinipati Show all

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

DOI: 10.1103/8x1h-39dp

Abstract

We measure the time-integrated CP asymmetry in D0 → K0SK0S decays reconstructed in e+e- → c¯c events collected by the Belle and Belle II experiments. The corresponding data samples have integrated luminosities of 980 and 428 fb-1, respectively. To infer the flavor of the D0 meson, we exploit the correlation between the flavor of the reconstructed decay and the electric charges of particles reconstructed in the rest of the e+e− → c¯c event. This results in a sample which is independent from any other previously used at Belle or Belle II. The result, ACP(D0 → K0 SK0S) =(1.3 ± 2.0 ± 0.2)%, where the first uncertainty is statistical and the second systematic, is consistent with previous determin..

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