48 citations · 402 across the 22 of their papers we have counts for
22 papers
Experimental study of excited states of Ni via one-neutron transfer up to the neutron-separation threshold and characteristics of the pygmy dipole resonance states
M. Spieker, L. T. Baby, A. L. Conley +5
The degree of collectivity of the Pygmy Dipole Resonance (PDR) is an open question. Recently, Ries {\it et al.} have suggested the onset of the PDR beyond based on the obser…
Decay Spectroscopy of Eu: Quasiparticle Configurations of Excited States and Structure of = Band-heads in Gd
D. Yates, R. Kruecken, I. Dillmann +45
\noindent \textbf{Background:} Detailed spectroscopy of neutron-rich, heavy, deformed nuclei is of broad interest for nuclear astrophysics and nuclear structure. Nuclei in the r-pr…
Hexadecapole strength in the rare isotopes Kr
M. Spieker, S. E. Agbemava, D. Bazin +14
In the Ge-Sr mass region, isotopes with neutron number are known to feature rapid shape changes with both nucleon number and angular momentum. To gain new insights into…
Investigation of octupole collectivity near the shape-transitional point
M. Spieker, L. A. Riley, P. D. Cottle +13
Enhanced octupole collectivity is expected in the neutron-deficient Ge, Se and Kr isotopes with neutron number and has indeed been observed for Ge. Shape c…
Accessing the Single-Particle Structure of the Pygmy Dipole Resonance in Pb
M. Spieker, A. Heusler, B. A. Brown +8
New experimental data on the neutron single-particle character of the Pygmy Dipole Resonance (PDR) in Pb are presented. They were obtained from and resonant proton…
Collective 2p-2h intruder states in Sn studied via -decay of In using GRIFFIN
K. Ortner, C. Andreoiu, M. Spieker +25
The low-lying structure of semi-magic Sn has been investigated through the -decay of In ( min) to study shape coexistence via the reduced transitio…
Experimental identification of the , state of Co and isospin symmetry in studied via one-nucleon knockout reactions
M. Spieker, D. Weisshaar, A. Gade +15
New experimental data obtained from -ray tagged one-neutron and one-proton knockout from Co is presented. A candidate for the sought-after state…
Two-neutron knockout as a probe of the composition of states in Mg, Al, and Si
B. Longfellow, A. Gade, J. A. Tostevin +12
Simpson and Tostevin proposed that the width and shape of exclusive parallel momentum distributions of the A-2 residue in direct two-nucleon knockout reactions carry a measurable s…
One-proton and one-neutron knockout reactions from Ni to the mirror pair Co and Ni
M. Spieker, A. Gade, D. Weisshaar +15
We present a high-resolution in-beam -ray spectroscopy study of excited states in the mirror nuclei Co and Ni following one-nucleon knockout from a projectile beam…
Spectroscopy and lifetime measurements near the proton drip line: P
B. Longfellow, A. Gade, B. A. Brown +10
We report on the observation of excited states in the neutron-deficient phosphorus isotopes P via in-beam gamma-ray spectroscopy with both high-efficiency and high-res…
Fine structure of the pygmy quadrupole resonance in Sn isotopes
N. Tsoneva, M. Spieker, H. Lenske +1
The electric quadrupole response in Sn isotopes is investigated by energy-density functional (EDF) and three-phonon quasiparticle-phonon model (QPM) theory with special…
Shape coexisistence and collective low-spin states in Sn studied with the DSA coincidence technique
M. Spieker, P. Petkov, E. Litvinova +5
Proton-scattering experiments followed by the coincident spectroscopy of rays have been performed at the Institute for Nuclear Physics of the University of Cologne to excite lo…
High-resolution study of low-spin states in Pu: Octupole excitations, clustering, and other structure features
M. Spieker, S. Pascu, D. Bucurescu +6
A high-resolution experiment at = 24 MeV was performed to populate low-spin states in the actinide nucleus Pu. The Q3D magnetic spectrograph of the Maier-L…
Combining γ-ray and particle spectroscopy with SONIC@HORUS
S. G. Pickstone, M. Weinert, M. Färber +10
The particle spectrometer SONIC for particle- coincidence measurements was commissioned at the Institute for Nuclear Physics in Cologne, Germany. SONIC consists of up to 12 sili…
A revised value in the semi-magic nucleus Po
D. Kocheva, G. Rainovski, J. Jolie +29
The lifetimes of the , the and the states of Po have been measured in the Pb(C,Be)Po transfer reaction by the Doppler-s…
Lifetime measurement of excited low-spin states via the ) reaction
A. Hennig, V. Derya, M. N. Mineva +4
In this article a method for lifetime measurements in the sub-picosecond regime via the Doppler-shift attenuation method (DSAM) following the inelastic proton scattering reaction i…
Origin of Low-Lying Enhanced E1 Strength in Rare-Earth Nuclei
M. Spieker, S. Pascu, A. Zilges +1
The experimental strength distribution below 4 MeV in rare-earth nuclei suggests a local breaking of isospin symmetry. In addition to the octupole states, additional sta…
Experimental constraints on the -ray strength function in Zr using partial cross sections of the Y(p,)Zr reaction
L. Netterdon, A. Endres, S. Goriely +4
Partial cross sections of the Y(p,)Zr reaction have been measured to investigate the -ray strength function in the neutron-magic nucleus Zr. For five pro…
Mixed-symmetry octupole and hexadecapole excitations in the N=52 isotones
A. Hennig, M. Spieker, V. Werner +18
Background: Excitations with mixed proton-neutron symmetry have been previously observed in the isotones. Besides the well established quadrupole mixed-symmetry states (MSS)…
The gamma-ray spectrometer HORUS and its applications for nuclear astrophysics
L. Netterdon, V. Derya, J. Endres +8
A dedicated setup for the in-beam measurement of absolute cross sections of astrophysically relevant charged-particle induced reactions is presented. These, usually very low, cross…
Possible experimental signature of octupole correlations in the 0 states of the actinides
M. Spieker, D. Bucurescu, J. Endres +8
= 0 states have been investigated in the actinide nucleus Pu up to an excitation energy of 3 MeV with a high-resolution (p,t) experiment at = 24 MeV. To t…
Nuclear astrophysics with radioactive ions at FAIR
R. Reifarth, S. Altstadt, K. Göbel +317
The nucleosynthesis of elements beyond iron is dominated by neutron captures in the s and r processes. However, 32 stable, proton-rich isotopes cannot be formed during those proces…