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Combined analysis of Belle and Belle II data to determine the CKM angle ϕ3 using B+D(\( {K}_S^0 \)h+h)h+ decays

A preprint version of the article is available at arXiv.


We present a measurement of the Cabibbo-Kobayashi-Maskawa unitarity triangle angle ϕ3 (also known as γ) using a model-independent Dalitz plot analysis of B+D (\( {K}_S^0 \)h+h)h+, where D is either a D0 or \( \overline{D} \)0 meson and h is either a π or K. This is the first measurement that simultaneously uses Belle and Belle II data, combining samples corresponding to integrated luminosities of 711 fb1 and 128 fb1, respectively. All data were accumulated from energy-asymmetric e+e collisions at a centre-of-mass energy corresponding to the mass of the Υ(4S) resonance. We measure ϕ3 = (78.4 ± 11.4 ± 0.5 ± 1.0)°, where the first uncertainty is statistical, the second is the experimental systematic uncertainty and the third is from the uncertainties on external measurements of the D-decay strong-phase parameters.


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The Belle and Belle II collaborations., Abudinén, F., Aggarwal, L. et al. Combined analysis of Belle and Belle II data to determine the CKM angle ϕ3 using B+D(\( {K}_S^0 \)h+h)h+ decays. J. High Energ. Phys. 2022, 63 (2022).

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  • B Physics
  • CKM Angle Gamma
  • e +-e Experiments