TY  - JOUR
A1  - Spieker, Mark-Christoph
A1  - Tsoneva, Nadja
A1  - Derya, Vera
A1  - Endres, Janis
A1  - Savran, Deniz
A1  - Harakeh, Muhsin N.
A1  - Harissopulos, Sotirios
A1  - Herzberg, Rolf-Dietmar
A1  - Lagoyannis, Anastasios
A1  - Lenske, Horst
A1  - Pietralla, Norbert
A1  - Popescu, Lucia
A1  - Scheck, Marcus
A1  - Schlüter, Friederike
A1  - Sonnabend, Kerstin
A1  - Stoica, Victor Ionuț
A1  - Wörtche, Heinrich Johannes
A1  - Zilges, Andreas
T1  - The pygmy quadrupole resonance and neutron-skin modes in 124Sn
T2  - Physics Letters B
N2  - 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, (α,α' γ ) and (γ , γ') experiments were performed on 124Sn. In both reactions, Jπ = 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 (γ , γ') experiment, while the (α,α'γ ) experiment at the chosen kinematics strongly favors the excitation of surface modes because of the strong α-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 γ -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 124Sn.
KW  - Atomic nuclei
KW  - Collective quadrupole excitations
KW  - Pygmy quadrupole resonance
KW  - 124Sn
Y1  - 2015
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/54681
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-546810
SN  - 1873-2445
SN  - 0370-2693
VL  - 752.2016
PB  - Elsevier
CY  - Amsterdam
ER  -