Electron and photon scattering on three-nucleon bound states

Abstract

A big spectrum of processes induced by real and virtual photons on the 3 He and 3 H nuclei is theoretically investigated through many examples based on nonrelativistic Faddeev calculations for bound and continuum states. The modern nucleon-nucleon potential AV18 together with the threenucleon force UrbanaIX is used. The single nucleon current is augmented by explicit π-and ρ-like two-body currents which fulfill the current continuity equation together with the corresponding parts of the AV18 potential. We also employ the Siegert theorem, which induces many-body contributions to the current operator. The interplay of these different dynamical ingredients in the various electromagnetic processes is studied and the theory is compared to the experimental data.Overall we find fair to good agreement but also cases of strong disagreement between theory and experiment, which calls for improved dynamics. In several cases we refer the reader to the work of other groups and compare their results with ours. In addition we list a number of predictions for observables in different processes which would challenge this dynamical scenario even more stringently and systematically.

Signatures of the chiral two-pion exchange electromagnetic currents in theH2andHe3Rozpędzik1, Golak2, Kölling3 et al. 2011Phys. Rev. CSelf Cite313541View full textAdd to dashboardCite

“…In the second case, we have three free nucleons in the final state and their asymptotic relative motions are represented by p and q. In order to calculate the crucial matrix elements N µ given in (4.1), it is not necessary to solve the corresponding Faddeev equations directly for the 3N scattering states [11]. Instead, we solve a Faddeev-type equation for an auxiliary state | U .…”

“…For details about the solution of Eqs (4.3)-(4.4), see Ref. [11]. It is important to mention that these equations are solved in the partial wave basis.…”

“…It has been a subject of intense experimental and theoretical research for several decades (see Refs [7,8]). Also photodisintegration of 3 He has been studied experimentally and theoretically for a long time [9][10][11]. Photodisintegration observables provide a good tool for studying the contributions from meson exchange currents (MEC) to the nuclear current operator.…”

Studies of three-nucleon systems with improved chiral forces

“…Compared to elastic scattering, a new dynamical ingredient, namely the electromagnetic current operator j μ , enters the calculation. The transition amplitude for radiative capture can be obtained via time reversal symmetry from the transition amplitude N Nd μ for two-body photodisintegration of the corresponding 3N bound state, γ + 3 He → p + d in our case [8,9].…”

“…In the following, we use the Siegert theorem to include implicitly many-body electromagnetic current operators (see [8,9] for more details).…”