Search for scaling onset in exclusive reactions with the lightest nuclei

TL;DR

This paper discusses the scaling behavior of exclusive reactions involving light nuclei at moderate energies, exploring the potential for observing quark-level phenomena and symmetry restoration in nuclear interactions.

Contribution

It proposes a systematic experimental study of scaling in reactions with light nuclei at the JINR Nuclotron, extending previous observations to nuclear systems.

Findings

Scaling observed at moderate energies in reactions with light nuclei

Potential indication of symmetry restoration in nuclear processes

Proposal for experimental investigation at JINR Nuclotron

Abstract

The dimensional scaling of the differential cross sections of binary reactions $d\sigma/d t\sim s^{-(n-2)}$, where $n$ is given by constituent quark counting rules, was predicted for asymptotically high energies $\sqrt{s}\gg m_i$ and transferred momenta $-t\gg m_i^2$ at $t/s=const$ (here $s$ and $t$ are the Mandelstam variables and $m_i$ denotes a hadron mass), but manifested itself at surprisingly moderate energies of few GeV at large fixed cms angles $\theta_{cm}\sim 90^\circ$. This behaviour is observed not only in reactions with free hadrons, but with the deuteron and $^3He$ 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, $^3H$, $^3He$, and $^4He$ nuclei is still absent. We consider a possibility to carry out this study in $dd$ collisions at the JINR Nuclotron.