Isoscalar dipole coherence at low energies and forbidden E1 strength

Details Isoscalar dipole coherence at low energies and forbidden E1 strength Isoscalar dipole coherence at low energies and forbidden E1 strength

2010-11-04

arxiv.org/abs/1011.1162v1

Eur.Phys.J.A47:14,2011

Physics

Nuclear Physics

Nuclear Theory

9 pages, 6 figures, EPJA submitted

Scientific paper

10.1140/epja/i2011-11014-7

In 16O and 40Ca an isoscalar, low-energy dipole transition (IS-LED) exhausting approximately 4% of the isoscalar dipole (ISD) energy-weighted sum rule is experimentally known, but conspicuously absent from recent theoretical investigations of ISD strength. The IS-LED mode coincides with the so-called isospin-forbidden E1 transition. We report that for N=Z nuclei up to 100Sn the fully self-consistent Random-Phase-Approximation with finite-range forces, phenomenological and realistic, yields a collective IS-LED mode, typically overestimating its excitation energy, but correctly describing its IS strength and electroexcitation form factor. The presence of E1 strength is solely due to the Coulomb interaction between the protons and the resulting isospin-symmetry breaking. The smallness of its value is related to the form of the transition density, due to translational invariance. The calculated values of E1 and ISD strength carried by the IS-LED depend on the effective interaction used. Attention is drawn to the possibility that in N-not-equal-Z nuclei this distinct mode of IS surface vibration can develop as such or mix strongly with skin modes and thus influence the pygmy dipole strength as well as the ISD strength function. In general, theoretical models currently in use may be unfit to predict its precise position and strength, if at all its existence.

Affiliated with

Also associated with

No associations

Rating

Isoscalar dipole coherence at low energies and forbidden E1 strength 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 Isoscalar dipole coherence at low energies and forbidden E1 strength, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Isoscalar dipole coherence at low energies and forbidden E1 strength will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-146010