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arXiv · hep-ex/0308001

J/Psi Polarization in 800-GeV p-Cu Interactions

T. H. Chang·M. E. Beddo·C. N. Brown·T. A. Carey·W. E. Cooper·C. A. Gagliardi·G. T. Garvey·D. F. Geesaman·E. A. Hawker·X. C. He·L. D. Isenhower·D. M. Kaplan·S. B. Kaufman·D. D. Koetke·G. S. Kyle·P. L. McGaughey·W. M. Lee·M. J. Leitch·J. M. Moss·B. A. Mueller·V. Papavassiliou·J. C. Peng·G. Petitt·P. E. Reimer·M. E. Sadler·W. E. Sondheim·P. W. Stankus·R. S. Towell·R. E. Tribble·M. A. Vasiliev·J. C. Webb·J. L. Willis·G. R. Young
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Abstract

We present measurements of the polarization of the $ J/ψ$ produced in 800-GeV proton interactions with a copper target. Polarization of the $ J/ψ$ is sensitive to the $ c \bar{c} $ production and hadronization processes. A longitudinal polarization is observed at large $ x_{F} $, while at small $ x_{F} $ the state is produced essentially unpolarized or slightly transversely polarized. No significant variation of the polarization is observed versus $ p_{T} $.

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T. H. Chang, M. E. Beddo, C. N. Brown, T. A. Carey, W. E. Cooper, C. A. Gagliardi, G. T. Garvey, D. F. Geesaman, E. A. Hawker, X. C. He, L. D. Isenhower, D. M. Kaplan, S. B. Kaufman, D. D. Koetke, G. S. Kyle, P. L. McGaughey, W. M. Lee, M. J. Leitch, J. M. Moss, B. A. Mueller, V. Papavassiliou, J. C. Peng, G. Petitt, P. E. Reimer, M. E. Sadler, W. E. Sondheim, P. W. Stankus, R. S. Towell, R. E. Tribble, M. A. Vasiliev, J. C. Webb, J. L. Willis, G. R. Young. 2003-07-31. J/Psi Polarization in 800-GeV p-Cu Interactions. https://doi.org/10.1103/physrevlett.91.211801

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