3H production via neutron-neutron-deuteron recombination

Abstract

We study the recombination of two neutrons and deuteron into neutron and 3 H using realistic nucleon-nucleon potential models. Exact Alt, Grassberger, and Sandhas equations for the fournucleon transition operators are solved in the momentum-space framework using the complex-energy method with special integration weights. We find that at astrophysical or laboratory neutron densities the production of 3 H via the neutron-neutron-deuteron recombination is much slower as compared to the radiative neutron-deuteron capture. We also calculate neutron-3 H elastic and total cross sections.

Four-body calculation of elastic deuteron-deuteron scattering

“…Overall a good reproduction of the experimental data was achieved when using realistic nucleon-nucleon (N N ) potentials. The most remarkable discrepancies above breakup threshold are the nucleon analyzing power and polarization, especially for the 3 H(p, n) 3 He charge exchange reaction, and the minimum of the differential cross section in elastic p + 3 He and n + 3 He scattering above 25 MeV nucleon energy. One may raise the question whether these disagreements are dominated by T = 1 states, or if T = 0 components have similar shortcomings as well.…”

“…Previous studies [1,[3][4][5][6] were mostly devoted to 4N reactions initiated by nucleon-trinucleon (N + 3N ) collisions, i.e., neutron (n) or proton (p) beams impinging on 3 H or 3 He targets. While n + 3 H and p + 3 He elastic scattering are dominated by states with total 4N isospin T = 1, the coupled n + 3 He and p + 3 H reactions involve both T = 0 and T = 1.…”

Four-body calculation of H2(d,p)H3 and Deltuva1, Fonseca2 2017Phys. Rev. CSelf Cite

“…We observe a few small discrepancies between predictions and data, mostly for iT 11 and T 20 at Θ c.m. < 60 model is again visible, especially for iT 11 , but shows no clear correlation with the trinucleon binding energy.…”

“…In the last 10 years significant progress has taken place in exact ab initio calculations of two-cluster scattering in the four-nucleon system, both below [1][2][3][4][5][6][7][8][9] and above [10][11][12][13][14][15][16][17] the breakup threshold. In the case of multichannel reactions, i.e., processes with open rearrangements and/or breakup channels, the most advanced calculations were performed by solving the Alt, Grassberger, and Sandhas (AGS) equations [18,19] for the four-particle transition operators in the momentum-space framework.…”

Momentum-Space Calculation of 4He Triatomic System with Realistic Potential

“…The rate for the time reversed reaction, the three-atom recombination, is simply proportional to σ b with a kinematic factor [16] and therefore is not shown separately. These observables, owing to their inclusive character, can be obtained even without explicit calculation of breakup or recombination operator U 0 but just using the optical theorem for U .…”