Model independent determination of the spin of the \(\Omega^{-}\) and its polarization alignment in \(\psi(3686)\rightarrow\Omega^{-}\bar{\Omega}^{+}\)

• Published in: arXiv.org 2021-02
• Main Authors: Anita, Bettoni, D, Bloms, J, Cetin, S A, Chang, J F, Chang, W L, Chen, G, Chen, M L, Chen, X R, Dong, M Y, Feng, C Q, Gao, Y, Garzia, I, Gu, L M, Gu, M H, S Gu, Gu, Y T, Guo, Y P, Guskov, A, Heinsius, F H, Huang, Y P, Q Ji, Jiang, X Y, Jin, S, Khoukaz, A, Koch, L, Kuessner, M, Lane, J J, Larin, P, Lavezzi, L, Li, H J, Li, Ke, Li, P R, Li, W D, Liang, H, Liang, Y F, Libby, J, Liu, B J, Liu, D, Liu, F H, Liu, J B, Liu, K, Liu, L, Liu, Q, Liu, Shuai, Liu, Z Q, Lu, H J, Lu, J D, Lu, Y P, Luo, M X, Ma, L L, Ma, X X, Mao, Z P, Mo, X H, Mo, Y J, Muramatsu, H, Nakhoul, S, Nefedov, Y, Peters, K, Ping, J L, Pitka, A, Qian, Z, Shan, X Y, Shen, C P, Shi, R S, Shi, X, Shi, X D, Song, J J, Sun, S S, Tan, Y H, Tang, G Y, Wang, X L, Wang, Y, Wang, Ziyi, Wei, D H, Wilkinson, G, Wolke, M, Wu, L H, Xiong, X A, Xu, J J, Xu, Q J, Yang, S L, Yang, Y H, Yu, B X, Yu, J S, Yuan, X Q, Zhang, H Y, Zhang, J Y, Zhang, J Z, Zhang, Jiawei, Zhang, Lei, Zhang, S, Zhang, X Y, Zhang, Y H, Zhao, Ling, Zheng, Y H, Zhou, L P, Zhou, X, Zhu, J, Zhu, X L
• Format: Article
• Language: English
• Subjects: Amplitudes; Angular distribution; Chain branching; Decay; Helicity
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2007.03679

We present an analysis of the process \(\psi(3686) \to \Omega^- \bar{\Omega}^+\) (\(\Omega^-\to K^-\Lambda\), \(\bar{\Omega}^+\to K^+\bar{\Lambda}\), \(\Lambda\to p\pi^-\), \(\bar{\Lambda}\to \bar{p}\pi^+\)) based on a data set of \(448\times 10^6\) \(\psi(3686)\) decays collected with the BESIII detector at the BEPCII electron-positron collider. The helicity amplitudes for the process \(\psi(3686) \to \Omega^- \bar{\Omega}^+\) and the decay parameters of the subsequent decay \(\Omega^-\to K^-\Lambda\) \((\bar{\Omega}^+\to K^+\bar{\Lambda})\) are measured for the first time by a fit to the angular distribution of the complete decay chain. The branching fraction of \(\psi(3686) \to \Omega^- \bar{\Omega}^+\) is measured to be \((5.82\pm 0.12\pm 0.24)\times 10^{-5}\), with an improved precision compared to previous measurements.