New mechanism for intermediate- and short-range nucleon-nucleon interaction

Description of intermediate- and short-range NN nuclear force within a covariant effective field theory

“…It has been shown [39] that when doing the nonrelativistic reduction of the above relativistic potentials we get the formulas very similar to those obtained in our previous fully microscopic semi-relativistic approach [29,30].…”

“…Hence, this intermediate dibaryon has a large width (∼ 300−400 MeV) and thus cannot be visualized as a resonance-like bump in NN phase shifts or cross sections. Our previous papers [3,29,30] have demonstrated that this two-stage mechanism is quite able to explain with reasonable σqq and πqq coupling constants NN phase shifts in low partial waves up to 1 GeV. So that, quite similar to the nucleon dressing by a pion field, the dibaryon is dressed mainly by the scalar-isoscalar σ-field and the physical dibaryon should exist partially in the bare state and in the dressed state.…”

“…The OPEpotential is taken here with soft cutoff constant Λ πN N = 700 MeV [29,30] which is dictated by all dynamical models of πN-interaction. The V TPE is approximated here, for the sake of simplicity, by a simple local gaussian function…”

“…The new force model proposed recently by two groups jointly: the Moscow State University group and the Tübingen University group [3,29,30,35], treats the intermediate-and short-range NN-interaction as that proceeding through an intermediate dressed six-quark bag (i.e. via s-channel mechanism):…”

Determination of Energy of n n-Singlet Virtual State in $$\varvec{d+{{}^{2}}}\hbox {H}\varvec{\rightarrow p+p+n+n}$$ d + 2

“…According to authors of Dibaryon Model of NN-interaction [4] the strong discrepancies of experiment and theory observed in nd-and pd-breakup reactions can be explained by a significant strengthening of nn-and pp-correlations of attractive character in the third nucleon field in 3 H (pnn) and 3 He (ppn) systems. New mechanism arising in the Dibaryon model − scalar σ-meson exchange between the nucleon and dibaryon -is presented as a diagram in Fig.…”