0000000000174655
AUTHOR
H. Göller
Relativistic corrections and unitary equivalence in elastic electron deuteron scattering.
The role of unitary equivalence of relativistic corrections in elastic electron deutron scattering is studied, starting from a class of approximately, unitarily equivalent Hamiltonians and using consistent charge density operators. The connection of various formal approaches for deriving the relativistic corrections to wave functions and operators are discussed in detail. For reasons of simplicity, we have chosen a pure one-pion-exchange model and calculated the charge and quadrupole form factors of the deuteron. The numerical results show that the unitary equivalence holds at small momentum transfers, but breaks down rather soon with increasing momentum transfers (\ensuremath{\lesssim}5 ${…
Gauge fields, hidden local symmetries, and meson exchange currents
Abstract The model dependence of the electromagnetic isovector meson exchange current (MEC) operator at higher momentums transfer is studied. For this purpose, the MEC operator constructed from a Lagrangian of the πϱa 1 system obtained within the framework of the hidden local symmetries (HLS) approach is compared with the analogous operator derived earlier from a minimal Yang-Mills (YM) Lagrangian. Numerical results for the deuteron disintegration near threshold show that the model dependent part of the exchange current modifies the tail of the cross section sensibly and that the presence of the a 1 meson both in the MEC and in the nuclear interaction provides a consistent description of th…
Relativistic Corrections and Unitary Equivalence
Model calculations of the charge and quadrupole deuteron form factors were performed starting from a class of approximately unitary equivalent Hamiltonians and using consistent charge density operators. The approximate unitary equivalence was tested numerically and found to break down already for rather small values of momentum transfer.
Consistent treatment of relativistic corrections in deuteron photodisintegration in a one-pion-exchange model
Using a one-pion-exchange model for the nucleon-nucleon interaction the relativistic corrections to potential and to the electromagnetic operators are derived in a power expansion of (p/M). All corrections up to the order (p/M)3 are consistently included. Numerical results are shown for differential cross section and polarization observables for deuteron photodisintegration. A sizeable influence of relativistic effects on some observables is found even at low energies. A comparison of our operators with the expressions of other authors is given.