Research output: Contribution to journal › Article › peer-review
Spin Dependence of η Meson Production in Proton-Proton Collisions Close to Threshold. / Adlarson, P.; Augustyniak, W.; Bardan, W. et al.
In: Physical Review Letters, Vol. 120, No. 2, 022002, 08.01.2018.Research output: Contribution to journal › Article › peer-review
}
TY - JOUR
T1 - Spin Dependence of η Meson Production in Proton-Proton Collisions Close to Threshold
AU - Adlarson, P.
AU - Augustyniak, W.
AU - Bardan, W.
AU - Bashkanov, M.
AU - Bass, S. D.
AU - Bergmann, F. S.
AU - Berłowski, M.
AU - Bondar, A.
AU - Büscher, M.
AU - Calén, H.
AU - Ciepał, I.
AU - Clement, H.
AU - Czerwiński, E.
AU - Demmich, K.
AU - Engels, R.
AU - Erven, A.
AU - Erven, W.
AU - Eyrich, W.
AU - Fedorets, P.
AU - Föhl, K.
AU - Fransson, K.
AU - Goldenbaum, F.
AU - Goswami, A.
AU - Grigoryev, K.
AU - Gullström, C. O.
AU - Heijkenskjöld, L.
AU - Hejny, V.
AU - Hüsken, N.
AU - Jarczyk, L.
AU - Johansson, T.
AU - Kamys, B.
AU - Kemmerling, G.
AU - Khatri, G.
AU - Khoukaz, A.
AU - Khreptak, O.
AU - Kirillov, D. A.
AU - Kistryn, S.
AU - Kleines, H.
AU - Kłos, B.
AU - Krzemień, W.
AU - Kulessa, P.
AU - Kupść, A.
AU - Kuzmin, A.
AU - Lalwani, K.
AU - Lersch, D.
AU - Lorentz, B.
AU - Magiera, A.
AU - Maier, R.
AU - Marciniewski, P.
AU - Shwartz, B.
AU - The WASA-at-COSY Collaboration
N1 - Publisher Copyright: © 2018 American Physical Society.
PY - 2018/1/8
Y1 - 2018/1/8
N2 - 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.
AB - 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.
KW - NEAR-THRESHOLD
KW - QUASI-FREE
KW - NUCLEON
KW - FACILITY
KW - COSY
UR - http://www.scopus.com/inward/record.url?scp=85040465958&partnerID=8YFLogxK
U2 - 10.1103/PhysRevLett.120.022002
DO - 10.1103/PhysRevLett.120.022002
M3 - Article
C2 - 29376676
AN - SCOPUS:85040465958
VL - 120
JO - Physical Review Letters
JF - Physical Review Letters
SN - 0031-9007
IS - 2
M1 - 022002
ER -
ID: 9288001