Search results for "isobar"
showing 10 items of 210 documents
Mass measurements on stable nuclides in the rare-earth region with the Penning-trap mass spectrometer RIGA-TRAP
2011
The masses of 15 stable nuclides in the rare-earth region have been measured with the Penning-trap mass spectrometer TRIGA-TRAP. This is the first series of absolute mass measurements linking these nuclides to the atomic-mass standard $^{12}\mathrm{C}$. Previously, nuclear reaction studies almost exclusively determined the literature values of these masses in the Atomic-Mass Evaluation. The TRIGA-TRAP results show deviations on the order of 3--4 standard deviations from the latest published values of the Atomic-Mass Evaluation 2003 for some cases. However, the binding-energy differences that are important for nuclear structure studies have been confirmed and improved. The new masses are dis…
First spatial separation of a heavy ion isomeric beam with a multiple-reflection time-of-flight mass spectrometer
2015
Physics letters / B 744, 137 - 141 (2015). doi:10.1016/j.physletb.2015.03.047
New isomer and decay half-life ofRu115
2010
Exotic, neutron-rich nuclei of mass $A=115$ produced in proton-induced fission of $^{238}\mathrm{U}$ were extracted using the IGISOL mass separator. The beam of isobars was transferred to the JYFLTRAP Penning trap system for further separation to the isotopic level. Monoisotopic samples of $^{115}\mathrm{Ru}$ nuclei were used for $\ensuremath{\gamma}$and $\ensuremath{\beta}$ coincidence spectroscopy. In $^{115}\mathrm{Ru}$ we have observed excited levels, including an isomer with a half-life of 76(6) ms and ($7/{2}^{\ensuremath{-}}$) spin and parity. The first excited 61.7-keV level in $^{115}\mathrm{Ru}$ with spins and parity ($3/{2}^{+}$) may correspond to an $\mathit{oblate}$ $3/{2}^{+}$…
"Decay Phase-Space Volume of Partial Waves" of "Light isovector resonances in $\pi^- p \to \pi^-\pi^-\pi^+ p$ at 190 GeV/${\it c}$"
2018
Decay phase-space volume $I_{aa}$ for the 14 selected partial waves as a function of $m_{3\pi}$, normalized such that $I_{aa}(m_{3\pi} = 2.5~\text{GeV}/c^2) = 1$. The wave index $a$ represents the quantum numbers that uniquely define the partial wave. The quantum numbers are given by the shorthand notation $J^{PC} M^\varepsilon [$isobar$] \pi L$. We use this notation to label the decay phase-space volume in the column headers. The labels are identical to the ones used in the column headers of the table of the transition amplitudes. $I_{aa}$ is calculated using Monte Carlo integration techniques for fixed $m_{3\pi}$ values, which are given in the first column, in the range from 0.5 to 2.5 Ge…
"Transition Amplitudes" of "Light isovector resonances in $\pi^- p \to \pi^-\pi^-\pi^+ p$ at 190 GeV/${\it c}$"
2018
Real and imaginary parts of the normalized transition amplitudes $\mathcal{T}_a$ of the 14 selected partial waves in the 1100 $(m_{3\pi}, t')$ cells (see Eq. (12) in the paper). The wave index $a$ represents the quantum numbers that uniquely define the partial wave. The quantum numbers are given by the shorthand notation $J^{PC} M^\varepsilon [$isobar$] \pi L$. We use this notation to label the transition amplitudes in the column headers. The $m_{3\pi}$ values that are given in the first column correspond to the bin centers. Each of the 100 $m_{3\pi}$ bins is 20 MeV/$c^2$ wide. Since the 11 $t'$ bins are non-equidistant, the lower and upper bounds of each $t'$ bin are given in the column he…
Case in favor of the N*(1700)(3/2(-))
2013
Using an interaction extracted from the local hidden-gauge Lagrangians, which brings together vector and pseudoscalar mesons, and the coupled channels rho N (s wave), pi N (d wave), pi Delta (s wave), and pi Delta (d wave), we look in the region ofv root s = 1400-1850 MeV and find two resonances dynamically generated by the interaction of these channels, which are naturally associated to N*(1520)(3/2(-)) and N*(1700)(3/2(-)). N*(1700)(3/2(-)) appears neatly as a pole in the complex plane. The free parameters of the theory are chosen to fit the pi N (d-wave) data. Both the real and imaginary parts of the pi N amplitude vanish in our approach in the vicinity of this resonance, which is simila…
The ASY-EOS experiment at GSI: Investigating the symmetry energy at supra-saturation densities
2012
The elliptic-flow ratio of neutrons with respect to protons in reactions of neutron rich heavy-ions systems at intermediate energies has been proposed as an observable sensitive to the strength of the symmetry term in the nuclear Equation Of State (EOS) at supra-saturation densities. The recent results obtained from the existing FOPI/LAND data for $^{197}$Au+$^{197}$Au collisions at 400 MeV/nucleon in comparison with the UrQMD model allowed a first estimate of the symmetry term of the EOS but suffer from a considerable statistical uncertainty. In order to obtain an improved data set for Au+Au collisions and to extend the study to other systems, a new experiment was carried out at the GSI la…
Feasibility of photodetachment isobar suppression of WF with respect to HfF
2014
Abstract The feasibility of using laser photodetachment as a means for isobar suppression in accelerator mass spectrometry has been investigated for the special case of HfF 5 − /WF 5 − . A method for absolute photodetachment cross section measurements was applied and the cross sections of tungsten pentafluoride and hafnium pentafluoride negative ions were measured. The measurements indicate that the photodetachment cross section for WF 5 − is at least 100 times larger than for HfF 5 − at the wavelength of the fourth harmonic of the Nd:YAG laser at 266 nm. The absolute cross section for WF 5 − at this photon energy was found to be (2.8 ± 0.3) × 10 −18 cm 2 , while an upper limit of 2 × 10 −…
Pressure and temperature dependence of the band-gap in CdTe
2003
In this paper we report on isothermal compression measurements (up to 5 GPa and 500 K) of the optical absorption edge of 1 μm epitaxial layers of CdTe growth by metalorganic chemical vapor deposition (MOCVD) on GaS substrates. The isothermal blue shift under pressure of the direct energy gap (Γ v 15 → Γ c 1 ) in the zinc-blende phase is about 7.1 × 10 -2 eV GPa -1 and is found to be independent of temperature within the experimental errors. The isobaric red shift in the stability range of the zinc-blende phase is about -3.76 × 10 -4 eV K -1 . Regarding the phase transitions, no discontinuity in the energy gap has been found in the narrow pressure range where the cinnabar phase can be presen…
Nature of the phase transition in spin crossover compounds
1990
Abstract Starting from the phenomenological free energy describing the spin equilibrium of continuous or gradual high spin (HS) ⇌ low spin (LS) transitions a reduced equation of state has been derived which is of the type known in mean field theories. The continuous HS ⇌ LS transitions of [Fe(2-pic-ND 2 ) 3 ]Cl 2 ·EtOD (2-pic = 2-picolylamine) at ambient pressure and p = 1200 bar and of [Fe(2-pic) 3 ]Cl 2 -MeOH can be classified as isobars above the critical point of the system. Around and below the critical point a complex behaviour is expected for thermodynamic reasons combined with the consequences of an elastic interaction mechanism between the HS and LS complex molecules in the crystal…