Adlarson, P., Augustyniak, W., Bardan, W. et al. (47 more authors) (2018) Spin Dependence of η Meson Production in Proton-Proton Collisions Close to Threshold. Physical Review Letters. 022002. ISSN 1079-7114
Abstract
Taking advantage of the high acceptance and axial symmetry of the WASA-at-COSY detector, and the high polarization degree of the proton beam of COSY, the reaction p→p→ppη has been measured close to threshold to explore the analyzing power Ay. The angular distribution of Ay is determined with the precision improved by more than 1 order of magnitude with respect to previous results, allowing a first accurate comparison with theoretical predictions. The determined analyzing power is consistent with zero for an excess energy of Q=15 MeV, signaling s-wave production with no evidence for higher partial waves. At Q=72 MeV the data reveal strong interference of Ps and Pp partial waves and cancellation of (Pp)2 and Ss∗Sd contributions. These results rule out the presently available theoretical predictions for the production mechanism of the η meson.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2018 American Physical Society |
Dates: |
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Institution: | The University of York |
Academic Units: | The University of York > Faculty of Sciences (York) > Physics (York) |
Depositing User: | Pure (York) |
Date Deposited: | 17 Sep 2018 13:40 |
Last Modified: | 05 Nov 2024 01:18 |
Published Version: | https://doi.org/10.1103/PhysRevLett.120.022002 |
Status: | Published |
Refereed: | Yes |
Identification Number: | 10.1103/PhysRevLett.120.022002 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:135808 |