Paper

Measurement of the CKM angle \\(\\) in \\(B^ D( K^0_ S h^+h^-)h^\\) decays with a novel approach

Li, D M, Ghorbanimoghaddam, Z, Battista, P B, Xiang, Z, Xu, Q N, Hu, J F, Xu, Q J, D Vico Benet, Che, G R, Shen, C P, Marangotto, D, Mathad, A, Santoro, L, Strekalina, D, Gys, T, Vecchi, S, Luo, J R, Luo, J S, Dzyuba, A, Pappalardo, L L, Kushnir, V, Pagare, B, Friday, D A, Gao, Y N, Wei, H R, Kaminaris, D, E van Herwijnen, Tisserand, V, Mulder, M, Libby, J, Wislicki, W, Punzi, G, Hennequin, A M, Tao, L Y, Zeng, F R, Jakoubek, T, Perret, P, Gao, Xu, Ma, Q M, Couturier, B, Gao, Y Y, Needham, M, T Hu, Schelhaas, Y, Wang, Shun, Pilato, R N, Wang, Zhi, Korchin, A, Jia, L K, Prouve, C, Wotton, S A, White, C, Spedicato, E, Gilman, A L, Nefedov, Y, Tang, G Y, Schmitz, H, Batozskaya, V, Govorkova, E, Houston, D C, Keizer, F, Elashri, M, Mitreska, B, Lee, H, Wang, X F, Riehn, F, Wang, X L, Wang, X N, Yin, H, Calefice, L, Wang, X W, Swientek, K, Khachatryan, V, Thomson-Strong, A R, Malik, Q A, Zhang, Z D, Fantechi, R, Galati, G, Abdelmotteleb, A S W, Dai, J P, Shao, M, Bottalico, E, Kvapil, J, Johnson, D, Biesuz, N V, Zhang, Shulei, Yan, X Q, Comerma-Montells, A, Luppi, E, Neri, N, You, Z Y, Yin, X, Minotti, A, Chang, H, Hemmer, F, M Senghi Soares, Muhammad, E, Zhang, Z Y, Li, Q M, T Li

2026

Overview

A measurement of the CKM angle \\(\\) and related strong-phase parameters is performed using a novel, model-independent approach in \\(B^ D( K^0_ S h^+h^-) h^\\) decays, where \\(h^() K\\). The analysis uses a joint data sample of electron-positron collisions collected by the BESIII experiment at the Beijing Electron-Positron Collider II during 2010--2011 and 2021--2022, corresponding to an integrated luminosity of 8 fb\\(^-1\\), and proton-proton collisions collected by the LHCb experiment at the Large Hadron Collider during 2011--2018, corresponding to an integrated luminosity of 9 fb\\(^-1\\). The two datasets are analyzed simultaneously by applying per-event weights based on the amplitude variation over the \\(D\\)-decay phase space to enhance the sensitivity to \\(C\\!P\\)-violating observables. The CKM angle \\(\\) is determined to be \\( = (71.3 5.0)^\\), which constitutes the most precise single measurement to date.

• Publisher: Cornell University Library, arXiv.org
• Subject: Collisions / Electron-positron accelerators / Large Hadron Collider / Luminosity / Particle accelerators / Protons