We report measurements of time-dependent CP asymmetries in B0→KS0π0γ decays based on a data sample of (388±6)×106 BB¯ events collected at the ϒ(4S) resonance with the Belle II detector. The Belle II experiment operates at the SuperKEKB asymmetric-energy e+e- collider. We measure decay-time distributions to determine CP -violating parameters S and C. We determine these parameters for two ranges of KS0π0 invariant mass: m(KS0π0)(0.8,1.0) GeV/c2, which is dominated by B0→K∗0(→KS0π0)γ decays, and a complementary region m(KS0π0)(0.6,0.8)(1.0,1.8) GeV/c2. Our results have improved precision as compared to previous measurements and are consistent with theory predictions.
Adachi, I., Aggarwal, L., Ahmed, H., Aihara, H., Akopov, N., Aloisio, A., et al. (2025). Measurement of CP Asymmetries in B0→KS0π0γ Decays at Belle II. PHYSICAL REVIEW LETTERS, 134(1), 011802-1-011802-8 [10.1103/physrevlett.134.011802].
Measurement of CP Asymmetries in B0→KS0π0γ 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
;Martini, A.Membro del Collaboration Group
;
2025-01-01
Abstract
We report measurements of time-dependent CP asymmetries in B0→KS0π0γ decays based on a data sample of (388±6)×106 BB¯ events collected at the ϒ(4S) resonance with the Belle II detector. The Belle II experiment operates at the SuperKEKB asymmetric-energy e+e- collider. We measure decay-time distributions to determine CP -violating parameters S and C. We determine these parameters for two ranges of KS0π0 invariant mass: m(KS0π0)(0.8,1.0) GeV/c2, which is dominated by B0→K∗0(→KS0π0)γ decays, and a complementary region m(KS0π0)(0.6,0.8)(1.0,1.8) GeV/c2. Our results have improved precision as compared to previous measurements and are consistent with theory predictions.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.