Measurement of branching-fraction ratios and CP asymmetries in B± → DCP±K± decays at Belle and Belle II.

Autor: Adachi, I., Aggarwal, L., Aihara, H., Akopov, N., Aloisio, A., Anh Ky, N., Asner, D. M., Atmacan, H., Aushev, T., Aushev, V., Aversano, M., Ayad, R., Babu, V., Bae, H., Bahinipati, S., Bambade, P., Banerjee, Sw., Barrett, M., Baudot, J., Bauer, M.
Zdroj: Journal of High Energy Physics; May2024, Vol. 2024 Issue 5, p1-26, 26p
Abstrakt: 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 π 0 , where D is an admixture of D0 and D ¯ 0 states. These decays are sensitive to the Cabibbo-Kobayashi-Maskawa unitarity-triangle angle ϕ3. The results are based on a combined analysis of the final data set of 772 × 106 B B ¯ pairs collected by the Belle experiment and a data set of 198 × 106 B 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 A CP+ = (+12.5 ± 5.8 ± 1.4)% and A CP− = (−16.7 ± 5.7 ± 0.6)%, and the ratios of branching fractions to be R CP+ = 1.164 ± 0.081 ± 0.036 and R CP− = 1.151 ± 0.074 ± 0.019. The first contribution to the uncertainties is statistical, and the second is systematic. The asymmetries A CP+ and 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° < ϕ3 < 16.5°) or (84.5° < ϕ3 < 95.5°) or (163.3° < ϕ3 < 171.5°) and 0.321 < rB < 0.465. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
Externí odkaz: