Search results for "nucleus"
showing 10 items of 1803 documents
Exclusive measurement of breakup reactions with the one-neutron halo nucleus11Be
2003
Electromagnetic and nuclear inelastic scattering of the halo nucleus ${}^{11}\mathrm{Be}$ have been investigated by a measurement of the one-neutron removal channel, utilizing a secondary ${}^{11}\mathrm{Be}$ beam with an energy of 520 MeV/nucleon impinging on lead and carbon targets. All decay products, i.e., ${}^{10}\mathrm{Be}$ fragments, neutrons, and $\ensuremath{\gamma}$ rays have been detected in coincidence. Partial cross sections for the population of ground and excited states in ${}^{10}\mathrm{Be}$ were determined for nuclear diffractive breakup as well as for electromagnetically induced breakup. The partial cross sections for ground-state transitions have been differentiated fur…
Character of particle-hole excitations in94Ru deduced fromγ-ray angular correlation and linear polarization measurements
2014
Linear polarization and angular correlations of gamma-rays depopulating excited states in the neutron-deficient nucleus Ru-94(44)50 have been measured, enabling firm spin-parity assignments for several excited states in this nucleus. The deduced multipolarities of strong transitions in the yrast structure were found to be mostly of stretched M1, E1, and E2 types and, in most cases, in agreement with previous tentative assignments. The deduced multipolarity of the 1869 keV and the connecting 257 and 1641 keV transitions indicates that the state at 6358 keV excitation energy has spin parity 12(1)(-) rather than 12(3)(+) as proposed in previous works. The presence of a 12(1)(-) state is interp…
Lifetime measurements and terminating structures in87Nb
2003
Two experiments have been performed using the Ni-58(S-32,3p) reaction at 135 MeV with Gammasphere and the Microball to study the high-spin structure of the transitional nucleus Nb-87. The first experiment using a thin target provided a considerable extension and refinement of the level scheme, as well as firm spin assignments from directional correlation of oriented nuclei. Sub-picosecond lifetimes were measured in the second backed-target experiment using the Doppler-shift attenuation method. The lifetimes imply a rather modest average deformation of beta(2)similar to0.1, but with considerable variation from state to state. Strong alternations were observed in the B(M1) strengths of transi…
βdecay of the5+isomer of the odd-odd nucleus100Nb
2001
The decay of the $3s$ isomer of ${}^{100}\mathrm{Nb}$ has been investigated by $\ensuremath{\gamma}$ spectroscopy of online mass separated ${}^{100}\mathrm{Nb}.$ Several new transitions in the daughter nucleus ${}^{100}\mathrm{Mo}$ have been observed. This results in a more consistent decay pattern leading to a firm ${5}^{+}$ assignment to the ${}^{100}\mathrm{Nb}$ isomer. A QRPA based calculation reproduces the decay features best if the $\ensuremath{\pi}{g}_{9/2}\ensuremath{-}\ensuremath{\pi}{p}_{1/2}$ gap is enlarged, confirming the importance of the subshell gap at $Z=40$ previously introduced to account for low-lying ${0}^{+}$ states in other $N=58$ isotones.
First observation of excited states inHg17595
2009
Excited states of the neutron-deficient nucleus Hg-175, populated using fusion-evaporation reactions, are reported for the first time. The spin and parity of the ground state has been determined to ...
Identification of the 13/2+ isomer in 199At
2000
The 13/2+ isomeric state in the 199At nucleus has been identified at an excitation energy of 573 keV and its half-life measured to be 580(130) ns using the recoil-decay tagging technique.
Observation of beta-delayed neutron decay to excited 0+ states in the residual nucleus: The case
1981
Abstract Beta-delayed neutron emission from 97 Rb to excited 0 + states in 96 Sr has been observed. The experimental branching ratios ( P n i ) are compared to predictions from a statistical model. It is demonstrated that, considering the influence of the strength of β -decay preceding neutron emission, the ( P n i ) reflect the different structure of the two excited 0 + states, in agreement with conclusions drawn from the measurement of their lifetimes.
Schematic model for narrowΔ(1232)resonances bound in a nucleus
2001
A schematic model explaining the recent evidence for bound states of the $\ensuremath{\Delta}(1232)$ resonance in ${}^{12}\mathrm{C}$ with a width of about 5 MeV found in the ${}^{12}\mathrm{C}{(e,e}^{\ensuremath{'}}p{\ensuremath{\pi}}^{\ensuremath{-}}{)}^{11}{\mathrm{C}}_{\mathrm{g}.\mathrm{s}.}$ is suggested. It interprets the observed narrow resonances as coherent bound states enforcing a fixed phase relation for the rescattering of the decay $\ensuremath{\pi}$'s in the nucleus. The coherent summing of the rescattering diagrams results in a cancellation of the tails of the resonance and a constructive interference in the maximum of the resonance leading to the observed narrow states at t…
CLUSTERIZATION AND THE HYPERDEFORMED STATE IN THE 36Ar NUCLEUS
2011
Cluster studies have predicted both the existence of a hyperdeformed state in 36 Ar ,1 and the favorite reaction channels 24 Mg +12 C , 20 Ne +16 O for its population.1,2 Recent experimental data seem to justify these predictions,3 and Nilsson-calculations give the same shape.4 According to structure-considerations it could also be built up in alpha-emitting reactions.