The pygmy quadrupole resonance and neutron-skin modes in 124 Sn
| Autor: | Mohsen Harakeh, Lucia Popescu, M. Spieker, Andreas Zilges, J. Endres, R-D Herzberg, Kerstin Sonnabend, Marcus Scheck, V. Stoica, Sotirios Harissopulos, N. Tsoneva, Deniz Savran, Norbert Pietralla, H. Lenske, F. Schlüter, H. J. Wörtche, V. Derya, A. Lagoyannis |
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| Přispěvatelé: | Research unit Nuclear & Hadron Physics |
| Rok vydání: | 2016 |
| Předmět: |
Nuclear and High Energy Physics
MAGIC NUCLEI Collective quadrupole excitations 01 natural sciences INELASTIC ALPHA-SCATTERING Atomic nuclei STRENGTH EXCITATION 0103 physical sciences ddc:530 Neutron Pygmy quadrupole resonance 010306 general physics Physics Isotope 010308 nuclear & particles physics lcsh:QC1-999 Dipole STATES Sn-124 Atomic nucleus Quadrupole Density functional theory DIPOLE RESONANCE Atomic physics 124Sn DECAY lcsh:Physics Excitation |
| Zdroj: | Physics Letters B: Nuclear Physics and Particle Physics Physics Letters B Physics Letters B, Vol 752, Iss C, Pp 102-107 (2016) Physics Letters B, 752, 102-107. ELSEVIER SCIENCE BV |
| ISSN: | 0370-2693 |
| DOI: | 10.1016/j.physletb.2015.11.004 |
| Popis: | We present an extensive experimental study of the recently predicted pygmy quadrupole resonance (PQR) in Sn isotopes, where complementary probes were used. In this study, (alpha,alpha 'gamma) and (gamma,gamma ') experiments were performed on Sn-124. In both reactions, J(pi)=2(+) states below an excitation energy of 5 MeV were populated. The E2 strength integrated over the full transition densities could be extracted from the (gamma,gamma ') experiment, while the (alpha, alpha 'gamma) experiment at the chosen kinematics strongly favors the excitation of surface modes because of the strong alpha-particle absorption in the nuclear interior. The excitation of such modes is in accordance with the quadrupole-type oscillation of the neutron skin predicted by a microscopic approach based on self-consistent density functional theory and the quasiparticle-phonon model (QPM). The newly determined gamma-decay branching ratios hint at a non-statistical character of the E2 strength, as it has also been recently pointed out for the case of the pygmy dipole resonance (PDR). This allows us to distinguish between PQR-type and multiphonon excitations and, consequently, supports the recent first experimental indications of a PQR in Sn-124. (C) 2015 The Authors. Published by Elsevier B.V. |
| Databáze: | OpenAIRE |
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