Search for scaling onset in exclusive reactions with the lightest nuclei

Abstract

Abstract. The dimensional scaling of the differential cross sections of binary reactions dσ/dt ∼ s −(n−2) , where n is given by constituent quark counting rules, was predicted for asymptotically high energies √ s ≫ mi and transferred momenta −t ≫ mi at t/s = const (here s and t are the Mandelstam variables and mi denotes a hadron mass), but manifested itself at surprisingly moderate energies of few GeV at large fixed cms angles θcm ∼ 90• . This behaviour is observed not only in reactions with free hadrons, but with the deuteron and 3 He too both for electromagnetic and pure hadronic interactions. One may suppose that observed scaling points out to effective restoration of near-conformal and, probably, chiral symmetry in these processes. A systematical experimental study of the scaling behaviour of the reactions with the deuteron, 3 H, 3 He, and 4 He nuclei is still absent. We consider a possibility to carry out this study in dd collisions at the JINR Nuclotron.PACS. 25.10.+s, Nuclear reactions involving few-nucleon systems -24.85.+p, Quarks, gluons, and QCD in nuclear reactions 25.55.-e, 2H-induced reactions

Possible Studies at the First Stage of the NICA Collider Operation with Polarized and Unpolarized Proton and Deuteron Beams

“…On the other hand, the reaction with pion production pp → dπ + does not follow CCR rule demostrating the differential cross section ∼ s −9 instead of s −12 . One possible way to explain this is a partial restortaion of chiral symmetry at enough high excitaion energy [147]. However, systematic study of these properties of the reactions with lightest nuclei are absent.…”