Physics – Nuclear Physics – Nuclear Theory
Scientific paper
2011-09-30
Physics
Nuclear Physics
Nuclear Theory
7 pages 4 figures
Scientific paper
The Busch-formula relates the energy-spectrum of two point-like particles interacting in a 3-D isotropic Harmonic Oscillator trap to the free scattering phase-shifts of the particles. This formula is used to find an expression for the \it shift \rm in the spectrum from the unperturbed (non-interacting) spectrum rather than the spectrum itself. This shift is shown to be approximately $\Delta=-\delta(k)/\pi\times dE$, where $dE$ is the spacing between unperturbed energy levels. The resulting difference from the Busch-formula is typically 1/2% except for the lowest energy-state and small scattering length when it is 3%. It goes to zero when the scattering length $\rightarrow \pm \infty$. The energy shift $\Delta$ is familiar from a relatedproblem, that of two particles in a spherical infinite square-well trap of radius $R$ in the limit $R\rightarrow \infty$. The approximation ishowever as large as 30% for finite values of $R$, a situation quite different from the Harmonic Oscillator case. The square-well results for $R\rightarrow \infty$ led to the use ofin-medium (effective) interactions in nuclear matter calculations that were $\propto \Delta$ and known as the \it phase shift approximation \rm.Our results indicate that the validity of this approximation depends on the trapitself, a problem already discussed by DeWitt more than 50 years ago for acubical vs spherical trap.
No associations
LandOfFree
Two Particles in a Trap does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Two Particles in a Trap, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Two Particles in a Trap will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-236504