Threshold open charm production in nucleon-nucleon collisions

Abstract

The associative charm particles production in nucleon-nucleon collisions N +N → Λc(Σc)+D+N , is described in a general way and the spin and isospin structure of the corresponding matrix elements are derived. Using an analogy with strange particle (ΛK)-production, the D−meson exchange model is considered in detail. Estimations of the energy behavior of the threshold cross sections show a large dependence on the form of the phenomenological hadron form factors and indicate that, at threshold, the cross section is three order of magnitude smaller than for strange particle production.

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

“…The spin and isospin structure of the matrix element for the reactions N + N → Λ C (Σ C ) + D + N was derived for open charm in Ref. [122]. Detailed estimation of cross sections and the expressions of the polarization observables can be found there.…”

Sub-threshold charm production in nuclear collisions

“…As one approaches the threshold energy required to produce charm in p+p collisions, as given in table I, one expects these perturbative methods to break down, especially in A+A collisions. Previous work on near threshold charm production, in A+A collisions, is based on a parametrized p+N cross section [15,16] or an effective interaction Lagrangian [17,18]. In such a study all charm is essentially produced in the first binary collisions, leading to binary scaling of charm production, thus the main contribution to sub-threshold production is from the Fermi momenta of the nucleons, shifting the threshold.…”

Sub‐threshold charm and strangeness production at GSI/FAIR energies

“…As one approaches the threshold energy required to produce charm in p + p collisions, as given in Table , one expects these perturbative methods to break down, especially in A + A collisions. Previous work on near‐threshold charm production in A + A collisions is based on a parameterized p + N cross‐section (Cassing et al ; Linnyk et al ) or an effective interaction Lagrangian (Liu et al ; Rekalo & Tomasi‐Gustafsson ). In such a study, all charm is essentially produced in the first binary collisions, leading to binary scaling of charm production; thus the main contribution to sub‐threshold production is from the Fermi momenta of the nucleons, shifting the threshold.…”