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arXiv · 2007.03679

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

M. Ablikim·M. N. Achasov·P. Adlarson·S. Ahmed·M. Albrecht·A. Amoroso·Q. An·Anita·X. H. Bai·Y. Bai·O. Bakina·R. Baldini Ferroli·I. Balossino·Y. Ban·K. Begzsuren·J. V. Bennett·N. Berger·M. Bertani·D. Bettoni·F. Bianchi·J Biernat·J. Bloms·A. Bortone·I. Boyko·R. A. Briere·H. Cai·X. Cai·A. Calcaterra·G. F. Cao·N. Cao·S. A. Cetin·J. F. Chang·W. L. Chang·G. Chelkov·D. Y. Chen·G. Chen·H. S. Chen·M. L. Chen·S. J. Chen·X. R. Chen·Y. B. Chen·W. S. Cheng·G. Cibinetto·F. Cossio·X. F. Cui·H. L. Dai·J. P. Dai·X. C. Dai·A. Dbeyssi·R. B. de Boer·D. Dedovich·Z. Y. Deng·A. Denig·I. Denysenko·M. Destefanis·F. De Mori·Y. Ding·C. Dong·J. Dong·L. Y. Dong·M. Y. Dong·S. X. Du·J. Fang·S. S. Fang·Y. Fang·R. Farinelli·L. Fava·F. Feldbauer·G. Felici·C. Q. Feng·M. Fritsch·C. D. Fu·Y. Fu·X. L. Gao·Y. Gao·Y. G. Gao·I. Garzia·E. M. Gersabeck·A. Gilman·K. Goetzen·L. Gong·W. X. Gong·W. Gradl·M. Greco·L. M. Gu·M. H. Gu·S. Gu·Y. T. Gu·C. Y Guan·A. Q. Guo·L. B. Guo·R. P. Guo·Y. P. Guo·A. Guskov·S. Han·T. T. Han·T. Z. Han·X. Q. Hao·F. A. Harris·K. L. He
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Abstract

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.

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M. Ablikim, M. N. Achasov, P. Adlarson, S. Ahmed, M. Albrecht, A. Amoroso, Q. An, Anita, X. H. Bai, Y. Bai, O. Bakina, R. Baldini Ferroli, I. Balossino, Y. Ban, K. Begzsuren, J. V. Bennett, N. Berger, M. Bertani, D. Bettoni, F. Bianchi, J Biernat, J. Bloms, A. Bortone, I. Boyko, R. A. Briere, H. Cai, X. Cai, A. Calcaterra, G. F. Cao, N. Cao, S. A. Cetin, J. F. Chang, W. L. Chang, G. Chelkov, D. Y. Chen, G. Chen, H. S. Chen, M. L. Chen, S. J. Chen, X. R. Chen, Y. B. Chen, W. S. Cheng, G. Cibinetto, F. Cossio, X. F. Cui, H. L. Dai, J. P. Dai, X. C. Dai, A. Dbeyssi, R. B. de Boer, D. Dedovich, Z. Y. Deng, A. Denig, I. Denysenko, M. Destefanis, F. De Mori, Y. Ding, C. Dong, J. Dong, L. Y. Dong, M. Y. Dong, S. X. Du, J. Fang, S. S. Fang, Y. Fang, R. Farinelli, L. Fava, F. Feldbauer, G. Felici, C. Q. Feng, M. Fritsch, C. D. Fu, Y. Fu, X. L. Gao, Y. Gao, Y. G. Gao, I. Garzia, E. M. Gersabeck, A. Gilman, K. Goetzen, L. Gong, W. X. Gong, W. Gradl, M. Greco, L. M. Gu, M. H. Gu, S. Gu, Y. T. Gu, C. Y Guan, A. Q. Guo, L. B. Guo, R. P. Guo, Y. P. Guo, A. Guskov, S. Han, T. T. Han, T. Z. Han, X. Q. Hao, F. A. Harris, K. L. He. 2020-07-07. Model independent determination of the spin of the $\Omega^{-}$ and its polarization alignment in $\psi(3686)\rightarrow\Omega^{-}\bar{\Omega}^{+}$. https://doi.org/10.1103/physrevlett.126.092002

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