Journal Article

Improved measurement of the strong-phase difference δDKπ in quantum-correlated DD¯ decays

Zhang, Z. Y, Guo, Y. P, Fritsch, M, Keshk, I. K, Yu, C. X, Qiu, J. F, Chang, W. L, Xiang, T, Destefanis, M, Zhao, Q, Li, Xiaoyu, Liang, H, Xiao, G. Y, Wang, T. J, Dong, M. Y, Larin, P, Yan, F, Liu, Y. B, Zhao, G, Han, W. Y, Xu, Q. J, Zhao, J, Hüsken, N, Cossio, F, Schnier, C, Sun, H. K, Jeong, J. H, Lu, F. X, Lei, Z. H, Bai, X. H, Yan, L, Liu, Y, Mangoni, A, Liu, X, Libby, J, Liu, T, Zhao, Ling, Kühn, W, Liu, Q, Sun, S. S, Liu, L, Lyu, Y. F, Jin, S, Cibinetto, G, Jang, E, Jiang, H. B, Jin, Y, Yang, Y. X, He, K. K, Schelhaas, Y, Zhang, P, Heng, Y. K, Redmer, C. F, Xu, G. F, Yu, B. X, Zhang, Y, Gao, Y. N, Bertani, M, Sang, H. S, Hou, G. Y, Liu, H, Zhao, J. Z, Chen, Y. B, Liu, K, Wiedner, U, Zhao, J. Y, Zou, B. S, Liu, C. X, Jia, Z. K, Nefedov, Y, Liu, D, Zhu, K. J, Shi, J. Y, Jiang, S. S, Imoehl, W, Ke, B. C, Batozskaya, V, Huang, L. Q, Zhang, H, Adlarson, P, Qi, M, Chen, M. L, Jaeger, S, Tat, M, Qin, J. J, Zhang, Y. H, Xiao, S. Y, Zhong, X, Xie, Z. P, Dai, H. L, Li, H. B, Lyu, X. R, Liu, B. J, Chen, X. R, Li, H. J, He, K. L, Li, H. N, Chen, X. T, Zhang, Y. T, Yu, X. D

2022

Overview

The decay D→K-π+ is studied in a sample of quantum-correlated DD¯ pairs, based on a data set corresponding to an integrated luminosity of 2.93 fb-1 collected at the ψ(3770) resonance by the BESIII experiment. The asymmetry between CP-odd and CP-even eigenstate decays into K-π+ is determined to be AKπ=0.132±0.011±0.007, where the first uncertainty is statistical and the second is systematic. This measurement is an update of an earlier study exploiting additional tagging modes, including several decay modes involving a KL0 meson. The branching fractions of the KL0 modes are determined as input to the analysis in a manner that is independent of any strong phase uncertainty. Using the predominantly CP-even tag D→π+π-π0 and the ensemble of CP-odd eigenstate tags, the observable AKππππ0 is measured to be 0.130±0.012±0.008. The two asymmetries are sensitive to rDKπcosδDKπ, where rDKπ and δDKπ are the ratio of amplitudes and phase difference, respectively, between the doubly Cabibbo-suppressed and Cabibbo-favoured decays. In addition, events containing D→K-π+ tagged by D→KS,L0π+π- are studied in bins of phase space of the three-body decays. This analysis has sensitivity to both rDKπcosδDKπ and rDKπsinδDKπ. A fit to AKπ, AKππππ0 and the phase-space distribution of the D→KS,L0π+π- tags yields δDKπ=187.6-9.7+8.9-6.4+5.4∘, where external constraints are applied for rDKπ and other relevant parameters. This is the most precise measurement of δDKπ in quantum-correlated DD¯ decays.

• Publisher: Springer Nature B.V
• Subject: Asymmetry / Decay / Eigenvectors / Fractions / Luminosity / Phase shift / Rapid prototyping / Sensitivity analysis / Tags / Uncertainty