V. Derya

Mixed-symmetry octupole and hexadecapole excitations in the N = 52 isotones

Background: Excitations with mixed proton-neutron symmetry have been previously observed in the N=52 isotones. Besides the well-established quadrupole mixed-symmetry states (MSS), octupole and hexadecapole MSS have been recently proposed for the nuclei Zr92 and Mo94. Purpose: The heaviest stable N=52 isotone Ru96 was investigated to study the evolution of octupole and hexadecapole MSS with increasing proton number. Methods: Two inelastic proton-scattering experiments on Ru96 were performed to extract branching ratios, multipole mixing ratios, and level lifetimes. From the combined data, absolute transition strengths were calculated. Results: Strong M1 transitions between the lowest-lying 3- and 4+ states were observed, providing evidence for a one-phonon mixed-symmetry character of the 32(-) and 42+ states. Conclusions: sdg-IBM-2 calculations were performed for Ru96. The results are in excellent agreement with the experimental data, pointing out a one-phonon hexadecapole mixed-symmetry character of the 42+ state. The 31-||M1||32(-) matrix element is found to scale with the 2s+||M1||2ms+ matrix element.

The high-efficiency γ-ray spectroscopy setup γ3 at HIγS

The existing Nuclear Resonance Fluorescence (NRF) setup at the HI{\gamma}S facility at the Triangle Universities Nuclear Laboratory at Duke University has been extended in order to perform {\gamma}-{\gamma} coincidence experiments. The new setup combines large volume LaBr3:Ce detectors and high resolution HPGe detectors in a very close geometry to offer high efficiency, high energy resolution as well as high count rate capabilities at the same time. The combination of a highly efficient {\gamma}-ray spectroscopy setup with the mono-energetic high-intensity photon beam of HI{\gamma}S provides a worldwide unique experimental facility to investigate the {\gamma}-decay pattern of dipole excitations in atomic nuclei. The performance of the new setup has been assessed by studying the nucleus \sulfur at 8.125 MeV beam energy. The {\gamma}-decay branching ratio from the

Magnetic dipole excitations ofCr50

1^+

Lifetime measurement of excited low-spin states via the (p,p′γ) reaction

level at 8125.4 keV to the first excited

Study of mixed-symmetry excitations in 96Ru via inelastic proton-scattering

2^+

Quadrupole decay strength of the M1 scissors mode

state was determined to 15.7(3)%.

The Pygmy Dipole Resonance – status and new developments

The low-lying

News on the Scissors Mode

M1

The high-efficiency {\gamma}-ray spectroscopy setup {\gamma}3 at HI{\gamma}S

-strength of the open-shell nucleus

The high-efficiency spectroscopy setup y³ at Hiys

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