The dd -> 4He eta Reaction Near Threshold

Abstract

The cross section for the reaction $dd\to {}^{4}He\eta$ close to threshold is estimated in a two-step model, similar to that which successfully describes near-threshold $pd\to {}^{3}He\eta$ production. A $\pi$-meson, created in a $dp\to {}^{3}He{\pi }^o$ process on one nucleon in the target deuteron, is converted into an $\eta$-meson by a secondary ${\pi }^{o}n\to n\eta$ reaction on the other nucleon. The kinematics are such that both processes are nearly physical so that only small Fermi momenta are required. The predictions of the model are in good agreement with recent Saclay experimental data. An analogous model, when applied to the near-threshold $n{}^{3}He\to {}^{4}He\eta$ reaction, predicts a cross section of a rather similar size, but experimental difficulties render this a doubtful means of studying the $\eta {}^{4}He$ interaction.

19 pages, latex including two figures. Two further Postscript figures are available on request to [email protected]

References in corpus (2)

• Near-Threshold Production of $\eta$-Mesons
• pi N --> eta N and eta N --> eta N partial wave T-matrices in a coupled, three channel model

Cited by in corpus (6)

• Eta-Helium Quasi-Bound States
• Interaction of eta mesons with nuclei
• Dependence of calculated binding energies and widths of $\eta$-mesic nuclei on treatment of subthreshold $\eta$-nucleon interaction
• Near threshold eta meson production in the d+d->alpha+eta reaction
• πN and ηp deexcitation channels of the N^* and Δbaryonic resonances between 1470 and 1680 MeV
• Two-pion production in deuteron-deuteron collisions at low energies