Odd and even partial waves of ηπ−ηπ− and η′π−η′π− in π−p→η(′)π−pπ−p→η(′)π−p at 191 GeV/c

C. Adolph (1) , V. Andrieux (2) , Y. Bedfer (2) , M Boer (2) , E. Burtin (2) , L. Capozza (2) , Q. Curiel (2) , A. Ferrero (2) , N. d'Hose (2) , F. Kunne (2) , M. Levillain (2) , A. Magnon (2) , C. Marchand (2) , D. Neyret (2) , S. Platchkov (2) , H. Wollny (2) , Collaboration Compass

1 Physikalisches Institut [Erlangen]
2 DPHN - Département de Physique Nucléaire (ex SPhN)

Exclusive production of ηπ− and ηπ− has been studied with a 191 GeV/c π− beam impinging on a hydrogen target at COMPASS (CERN). Partial-wave analyses reveal different odd/even angular momentum (L) characteristics in the inspected invariant mass range up to 3 GeV/c2. A striking similarity between the two systems is observed for the L = 2, 4, 6 intensities (scaled by kinematical factors) and the relative phases. The known resonances a2(1320) and a4(2040) are in line with this similarity. In contrast, a strong enhancement of ηπ− over ηπ− is found for the L = 1, 3, 5 waves, which carry non-q¯q quantum numbers. The L = 1 intensity peaks at 1.7 GeV/c2 in ηπ− and at 1.4 GeV/c2 in ηπ−, the corresponding phase motions with respect to L =2 are different.

Domaines: Physique Nucléaire Expérimentale [nucl-ex]

C. Adolph, V. Andrieux, Y. Bedfer, M Boer, E. Burtin, et al.. Odd and even partial waves of ηπ−ηπ− and η′π−η′π− in π−p→η(′)π−pπ−p→η(′)π−p at 191 GeV/c. Physics Letters B, 2015, 740, pp.303. ⟨10.1016/j.physletb.2014.11.058⟩. ⟨hal-01128365⟩