Pion production in nucleon-nucleon collisions and the issue of dibaryons
1 Physikalisches Institut, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 14, D-72076 Tübingen, Germany
2 Department of Physics, Tomsk State University, 36 Lenin Ave., Tomsk, 634050 Russia
3 School of Physics and Astronomy, The University of Edinburgh, James Clark Maxwell Building, Peter Guthrie Tait Road, Edinburgh EH9 3FD, Great Britain
* e-mail: firstname.lastname@example.org
Published online: 1 February 2019
Pion production in nucleon-nucleon collisions is tightly connected with the issue of dibaryons. After having established the existence of the narrow dibaryon resonance d* (2380) with I(JP) = 0(3+) by two-pion production and elastic proton-neutron scattering experiments, the discussion focuses now on its structure, whether it is a dilute molecular-like or a compact hexaquark object. These scenarios are confronted with experimental branching ratios and other observables. New WASA data for the pp → ppπ+π− reaction give evidence for the existence of an isotensor ΔN threshold state with JP = 1+ as calculated recently by Gal and Garcilazo and predicted earlier by Dyson and Xuong. New ANKE results suggest the dibaryon spectrum to be richer than expected.
© The Authors, published by EDP Sciences, 2019
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