  In reactions the wave packets of the emerging products typically are not
eigenstates of particle number operators or any other conserved quantities and
their properties are entangled. I describe a particle projection technique in
parts of space, which eschews the need to evaluate Pfaffians in the case of
overlap of generalized Slater determinants or Hartree-Fock-Bogoliubov type of
vacua. The extension of these formulas for calculating either angular momentum
or particle projected energy distributions of the reaction fragments are
presented as well. The generalization to simultaneous particle and angular
momentum projection of various reaction fragment observables is
straightforward.
