ABC effect as a signal of chiral symmetry restoration in hadronic collisions

作者：Platonova M N^*; Kukulin V I

来源：Physical Review C, 2013, 87(2): 025202.

DOI：10.1103/PhysRevC.87.025202

A nonconventional mechanism for the basic 2 pi-fusion reaction pn -> d + (pi pi)(0) in the energy region T-p = 1.0-1.4 GeV is suggested. The mechanism is aimed at providing a consistent explanation for the comprehensive experimental studies of this reaction in an exclusive setting done recently by the WASA-at-COSY Collaboration. The basic assumption of the model proposed is the production of the I (J(P)) = 0(3(+)) dibaryon resonance D-03 in the pn collision. The interference of two decay channels of this resonance-D-03 -> d + sigma -> d + (pi pi)(0) and D-03 -> D-12 + pi -> d + (pi pi)(0)-is shown to give a strong near-threshold enhancement in the pi pi invariant mass spectrum, which is well known as the Abashian-Booth-Crowe (ABC) effect. The sigma-meson parameters found to reproduce the ABC enhancement are in a general agreement with models which predict the chiral symmetry restoration at high excitation energy and/or high density of matter, although they are essentially less than those accepted for the free s meson. So, this result might be considered as an indication of partial chiral symmetry restoration in dense and excited quark matter. DOI: 10.1103/PhysRevC.87.025202

• 出版日期2013-2-15