We measure the time-integrated CP asymmetry, ACP, in D0 → π0π0 decays reconstructed in e+e− → cc̄ events collected by Belle II during 2019–2022. The data corresponds to an integrated luminosity of 428 fb−1. The D0 decays are required to originate from the flavor-conserving D*+ → D0π+ decay to determine the charm flavor at production time. Control samples of D0 → K−π+ decays, with or without an associated pion from a D*+ decay, are used to correct for detection asymmetries. The result, ACP(D0 → π0π0) = (0.30 ± 0.72 ± 0.20)%, where the first uncertainty is statistical and the second systematic, is consistent with CP symmetry.
Adachi, I., Ahn, Y., Akopov, N., Alghamdi, S., Alhakami, M., Aloisio, A., et al. (2025). Measurement of the time-integrated C P asymmetry in D 0 → π 0 π 0 decays at Belle II. PHYSICAL REVIEW D, 112(1), 012006-1-012006-12 [10.1103/vg9c-xvdc].
Measurement of the time-integrated C P asymmetry in D 0 → π 0 π 0 decays at Belle II
Branchini, P.Membro del Collaboration Group
;Budano, A.Membro del Collaboration Group
;Bussino, S.Membro del Collaboration Group
;De Pietro, G.Membro del Collaboration Group
;Laurenza, M.Membro del Collaboration Group
;Martellini, C.Membro del Collaboration Group
;Salutari, L.Membro del Collaboration Group
;
2025-01-01
Abstract
We measure the time-integrated CP asymmetry, ACP, in D0 → π0π0 decays reconstructed in e+e− → cc̄ events collected by Belle II during 2019–2022. The data corresponds to an integrated luminosity of 428 fb−1. The D0 decays are required to originate from the flavor-conserving D*+ → D0π+ decay to determine the charm flavor at production time. Control samples of D0 → K−π+ decays, with or without an associated pion from a D*+ decay, are used to correct for detection asymmetries. The result, ACP(D0 → π0π0) = (0.30 ± 0.72 ± 0.20)%, where the first uncertainty is statistical and the second systematic, is consistent with CP symmetry.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.


