Measurement of branching-fraction ratios and CP asymmetries in B$^{±}$ → D$_{CP±}$K$^{±}$ decays at Belle and Belle II

Adachi, I.; Aggarwal, L.; Aihara, H.; Akopov, N.; Aloisio, A.; Anh Ky, N.; Asner, D.M.; Atmacan, H.; Aushev, T.; Aushev, V.

doi:10.1007/JHEP05(2024)212

Measurement of branching-fraction ratios and CP asymmetries in B $^{±}$ → D $_{CP±}$ K $^{±}$ decays at Belle and Belle II

Belle and
Belle-II

Collaborations

Aug 9, 2023

Published in:

JHEP 05 (2024) 212

Published: May 17, 2024

e-Print:

2308.05048 [hep-ex]

DOI:

10.1007/JHEP05(2024)212

Report number:

Belle II Preprint 2023-011;KEK Preprint 2023-9

Experiments:

View in:

ADS Abstract Service

reference search9 citations

Citations per year

Abstract: (Springer)

We report results from a study of B

^{±}

→ DK

^{±}

decays followed by D decaying to the CP-even final state K

^{+}

K

^{−}

and CP-odd final state

{K}_S^0{\pi}^0

, where D is an admixture of D

^{0}

and

{\overline{D}}^0

states. These decays are sensitive to the Cabibbo-Kobayashi-Maskawa unitarity-triangle angle ϕ

_{3}

. The results are based on a combined analysis of the final data set of 772 × 10

^{6} B\overline{B}

pairs collected by the Belle experiment and a data set of 198 × 10

^{6} B\overline{B}

pairs collected by the Belle II experiment, both in electron-positron collisions at the Υ(4S) resonance. We measure the CP asymmetries to be

\mathcal{A} _{CP+}

= (+12.5 ± 5.8 ± 1.4)% and

\mathcal{A} _{CP−}

= (−16.7 ± 5.7 ± 0.6)%, and the ratios of branching fractions to be

\mathcal{R} _{CP+}

= 1.164 ± 0.081 ± 0.036 and

\mathcal{R} _{CP−}

= 1.151 ± 0.074 ± 0.019. The first contribution to the uncertainties is statistical, and the second is systematic. The asymmetries

\mathcal{A} _{CP+}

and

\mathcal{A} _{CP−}

have similar magnitudes and opposite signs; their difference corresponds to 3.5 standard deviations. From these values we calculate 68.3% confidence intervals of (8.5

^{°}

< ϕ

_{3}

< 16.5

^{°}

) or (84.5

^{°}

< ϕ

_{3}

< 95.5

^{°}

) or (163.3

^{°}

< ϕ

_{3}

< 171.5

^{°}

) and 0.321 < r

_{B}

< 0.465.[graphic not available: see fulltext]

B Physics
CKM Angle Gamma
CP Violation
e+-e− Experiments
electron positron: annihilation
electron positron: colliding beams
B: pair production
B: hadronic decay
B: branching ratio
branching ratio: ratio: measured

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Figures(2)

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