Isospin Character of the Pygmy Dipole Resonance in Sn-124

J. Endres, E. Litvinova, D. Savran, P. A. Butler, M. N. Harakeh, S. Harissopulos, R. -D. Herzberg, R. Kruecken, A. Lagoyannis, N. Pietralla, V. Yu Ponomarev, L. Popescu, P. Ring, M. Scheck, K. Sonnabend, V. I. Stoica, H. J. Wortche, A. Zilges

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Abstract

The pygmy dipole resonance has been studied in the proton-magic nucleus Sn-124 with the (alpha, alpha'gamma) coincidence method at E-alpha = 136 MeV. The comparison with results of photon-scattering experiments reveals a splitting into two components with different structure: one group of states which is excited in (alpha, alpha'gamma) as well as in (gamma, gamma') reactions and a group of states at higher energies which is only excited in (gamma, gamma') reactions. Calculations with the self-consistent relativistic quasiparticle time-blocking approximation and the quasiparticle phonon model are in qualitative agreement with the experimental results and predict a low-lying isoscalar component dominated by neutron-skin oscillations and a higher-lying more isovector component on the tail of the giant dipole resonance.
Original languageEnglish
Article number212503
JournalPhysical Review Letters
Volume105
Issue number21
DOIs
Publication statusPublished - 19 Nov 2010
Externally publishedYes

Cite this

Endres, J., Litvinova, E., Savran, D., Butler, P. A., Harakeh, M. N., Harissopulos, S., Herzberg, R. -D., Kruecken, R., Lagoyannis, A., Pietralla, N., Ponomarev, V. Y., Popescu, L., Ring, P., Scheck, M., Sonnabend, K., Stoica, V. I., Wortche, H. J., & Zilges, A. (2010). Isospin Character of the Pygmy Dipole Resonance in Sn-124. Physical Review Letters, 105(21), [212503]. https://doi.org/10.1103/PhysRevLett.105.212503