2006/02/01 by A. Shebeko, P. Papakonstantinou, E. Mavrommatis
Physics and Astronomy · #Cold Atom Physics and Bose-Einstein Condensates #Nuclear physics research studies #Quantum Mechanics and Non-Hermitian Physics #nucl-th
paper · pdf · doi:10.1140/epja/i2005-10247-3
published as Eur.Phys.J. A27 (2006) 143-155 · 13 pages, incl. 3 figures - to appear in Eur. Phys. J. A
openalex publication_date 2006/02/01 · arxiv created 2006/02/20 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/31
The one-body and two-body density matrices in coordinate space and their Fourier transforms in momentum space are studied for a nucleus (a nonrelativistic, self-bound finite system). Unlike the usual procedure, suitable for infinite or externally bound systems, they are determined as expectation values of appropriate intrinsic operators, dependent on the relative coordinates and momenta (Jacobi variables) and acting on intrinsic wavefunctions of nuclear states. Thus, translational invariance (TI) is respected. When handling such intrinsic quantities, we use an algebraic technique based upon the Cartesian representation, in which the coordinate and momentum operators are linear combinations of the creation and annihilation operators a+ and a for oscillator quanta. Each of the relevant multiplicative operators can then be reduced to the form: one exponential of the set a+ times other exponential of the set a. In the course of such a normal-ordering procedure we offer a fresh look at the appearance of "Tassie-Barker" factors, and point out other model-independent results. The intrinsic wavefunction of the nucleus in its ground state is constructed from a nontranslationally-invariant (nTI) one via existing projection techniques. As an illustration, the one-body and two-body momentum distributions (MDs) for the 4He nucleus are calculated with the Slater determinant of the harmonic-oscillator model as the trial, nTI wavefunction. We find that the TI introduces important effects in the MDs.