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

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

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

Authors

Description

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} $.
4 pages, 3 figures