Abstract
In a 3.5 event/ub exposure of the BNL 80″ bubble chamber we have observed the following reactions: pd → pdφ+φ−, pd → ppnφ+φ−, pd → pdφ+φ−φ0. The incident p momentum was 7.0 GeV/c. We give cross sections for the reactions, as well as for other reactions involving production of Λ We give detailed descriptions of the coherent final states (1) and (3). It is observed that reactions (1)-(3) are dominated by production of Δ−−(1236). We apply a Deck model, both in Reggeized and non-Reggeized form, to the reaction pd → Δ−−π+d and obtain satisfactory fits to the distributions of all kinematic variables. In particular, the π+d mass spectrum, which shows a prominent peak (the “d∗”) at a mass M(πd) ≈ 2170 MeV, is well reproduced by the predictions of the model without introducing a resonant interpretation for this effect. Modified versions of this model are applied to the reactions pd → Δ−−π+pn, and pd → Δ−−πOπ+d, which occur as sub-samples of the final states (2) and (3) respectively. Here also, prominent peaks are observed in the π+pn mass spectrum (in the former reaction) and in the π+d and πOd mass spectrum (in the latter reaction). Again the predictions of the model agree well with the observed distributions of all the kinematic variables.
Citation
ID:
272745
Ref Key:
zdanis1971nuclearcoherent