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First measurement of the CKM angle ϕ3 with B±→ D(\( {K}_{\mathrm{S}}^0 \)π+ππ0) K± decays


We present the first model-independent measurement of the CKM unitarity triangle angle ϕ3 using B±→ D(\( {K}_{\mathrm{S}}^0 \)π+ππ0) K± decays, where D indicates either a D0 or \( \overline{D} \)0 meson. Measurements of the strong-phase difference of the D →\( {K}_{\mathrm{S}}^0 \)π+ππ0 amplitude obtained from CLEO-c data are used as input. This analysis is based on the full Belle data set of 772 × 106B\( \overline{B} \) events collected at the Υ(4S) resonance. We obtain ϕ3 = (\( {5.7}_{-8.8}^{+10.2} \)±3.5±5.7)° and the suppressed amplitude ratio rB = 0.323±0.147±0.023±0.051. Here the first uncertainty is statistical, the second is the experimental systematic, and the third is due to the precision of the strong-phase parameters measured from CLEO-c data. The 95% confidence interval on ϕ3 is (29.7, 109.5)°, which is consistent with the current world average.

A preprint version of the article is available at ArXiv.


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Correspondence to P. K. Resmi.

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ArXiv ePrint: 1908.09499

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Resmi, P.K., Libby, J., Trabelsi, K. et al. First measurement of the CKM angle ϕ3 with B±→ D(\( {K}_{\mathrm{S}}^0 \)π+ππ0) K± decays. J. High Energ. Phys. 2019, 178 (2019).

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  • CKM angle gamma
  • CP violation
  • e+-e- Experiments
  • B physics
  • Flavor physics