학술논문
Measurement of branching-fraction ratios and CP asymmetries in B± → DCP± K± decays at Belle and Belle II
Document Type
Original Paper
Author
Source
Journal of High Energy Physics. 2024(5)
Subject
Language
English
ISSN
1029-8479
Abstract
Abstract: 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 KS0π0D¯0BB¯BB¯AARRAA, where D is an admixture of D0 and KS0π0D¯0BB¯BB¯AARRAA 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 KS0π0D¯0BB¯BB¯AARRAA pairs collected by the Belle experiment and a data set of 198 × 106 KS0π0D¯0BB¯BB¯AARRAA pairs collected by the Belle II experiment, both in electron-positron collisions at the Υ(4S) resonance. We measure the CP asymmetries to be KS0π0D¯0BB¯BB¯AARRAACP+ = (+12.5 ± 5.8 ± 1.4)% and KS0π0D¯0BB¯BB¯AARRAACP− = (−16.7 ± 5.7 ± 0.6)%, and the ratios of branching fractions to be KS0π0D¯0BB¯BB¯AARRAACP+ = 1.164 ± 0.081 ± 0.036 and KS0π0D¯0BB¯BB¯AARRAACP− = 1.151 ± 0.074 ± 0.019. The first contribution to the uncertainties is statistical, and the second is systematic. The asymmetries KS0π0D¯0BB¯BB¯AARRAACP+ and KS0π0D¯0BB¯BB¯AARRAACP− 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.