Matrix-isolated FeO,NiO, and CoO: Ground-state vibrational frequencies

The infrared vibrational spectra of the FeO, NiO, and CoO molecules have been observed in Ar matrices at 14 K. Frequencies for each of the isotopomers ⁵⁴Fe¹⁶O, ⁵⁴Fe¹⁸O, ⁵⁶Fe¹⁶O, ⁵⁶Fe¹⁸O, ⁵⁸Ni¹⁶O, ⁵⁸Ni¹⁸O, ⁶⁰Ni¹⁶O, ⁶⁰Ni¹⁸O, ⁵⁹Co¹⁶O, and ⁵⁹Co¹⁸O were measured. The derived vibrational constants are:

$\text{w}{}_{\mathrm{e}}\text{= 880.02 ± 1.2 and w}{}_{\mathrm{e}}\text{x}{}_{\mathrm{e}}\text{= 3.47 ± 0.6 cm}{}^{\mathrm{?1}}\text{for}{}^{56}\text{Fe}{}^{16}\text{O; w}{}_{\mathrm{e}}\text{= 837.61 ± 1.1 and w}{}_{\mathrm{e}}\text{x}{}_{\mathrm{e}}\text{= 5.92 ± 0.6 cm}{}^{\mathrm{?1}}\text{for}{}^{58}\text{Ni}{}^{16}\text{O; and w}{}_{\mathrm{e}}\text{= 853.75 ± 1.2 and w}{}_{\mathrm{e}}\text{x}{}_{\mathrm{e}}\text{= 3.65 ± 0.6 cm}{}^{\mathrm{?1}}\text{for}{}^{59}\text{Co}{}^{16}\text{O.}$

These results support the assignment of ⁵Σ⁺ as the ground state of FeO, ³Σ^? as the ground state of NiO, and ⁴Σ^? as the ground state of CoO.     

A new 5.0 ns isomer in 144Eu

A new 9^? isomeric state having a 5.0 ns half-life has been observed in ¹⁴⁴Eu following the ¹⁴⁴Sm(α, p3n) reactions at 50 MeV. The new isomer most likely has a $\text{(π}\text{g}{}^{\mathrm{?1}}{}_{\mathrm{<mtext>7</mtext><mtext>2</mtext>}}\text{v}\text{h}{}^{\mathrm{?1}}{}_{\mathrm{<mtext>11</mtext><mtext>2</mtext>}}\text{)}{}_9{}^{\mathrm{?}}$ configuration.     

A high-spin isomer in 204Bi

By making use of heavy-ion and α-particle induced reactions an isomeric state has been found in ²⁰⁴Bi, with a half-life of $\text{T}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{= 1.07 ± 0.03}\text{ms}$ and the quantum characteristics I^π = 16⁺. The four-quasiparticle configuration $\text{ν(}\text{i}{}_{\mathrm{<mtext>13</mtext><mtext>2</mtext>}}\text{)}{}^{\mathrm{?2}}\text{ν(}\text{f}{}_{\mathrm{<mtext>5</mtext><mtext>2</mtext>}}\text{)}{}^1\text{π(}\text{h}{}_{\mathrm{<mtext>9</mtext><mtext>2</mtext>}}\text{)}{}^1$ has been ascribed to this state.     

Level structure in 117Sb investigated in the decay of the isomeric three-quasiparticle state

The level structure of ¹¹⁷Sb was investigated in the reactions ¹¹⁵In(α, 2nγ)^117mSb, ¹¹⁷Sn(d, 2nγ)^117mSb and ¹¹⁷Sn(p, nγ)^117mSb. In order to confirm level sequences and to assign spins and parities to levels populated in the decay of the isomeric three-particle state $\text{T}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ = 340 μs), prompt and delayed γ-ray spectra, lifetimes, γ-γ coincidences, γ-ray angular distributions, conversion electrons and excitation functions were measured. The spin $\text{25}\text{2}$⁺ of the isomeric state can be explained by the three-particle configuration [$\text{π(}\text{d}{}_{\mathrm{<mtext>5</mtext><mtext>2</mtext>}}\text{); v(}\text{h}{}_{\mathrm{<mtext>11</mtext><mtext>2</mtext>}}\text{)}{}^2\text{10}{}^{\mathrm{+}}\text{]}\text{25}\text{2}{}^{\mathrm{+}}$. This is supported by the experimentally determined g-factor of g = O.115 ± 0.006. Other levels in ¹¹⁷Sb can be interpreted as particle states coupled to anharmonic vibrations of the core. The existence of an excited $\text{9}\text{2}{}^{\mathrm{+}}\text{[404]}$ quasirotational band is experimentally proved and is supported by calculations of the equilibrium deformation.     

g-Factors of high-spin isomers in 194Hg and 196Hg

The g-factors of the 10⁺ isomeric states in ¹⁹⁴Hg and ¹⁹⁶Hg have been measured using the in beam IPAD method. The results $\text{g(}{}^{194}\text{Hg}\text{) = ?0.24(4)}$ and $\text{g(}{}^{196}\text{Hg}\text{) = ?0.18(9)}$ are in agreement with the value expected for an ($\text{i}{}_1\text{3}\text{2}$^?2) neutron satructure and clearly contradict the previous assignment as ($\text{h}{}_{\mathrm{<mtext>1</mtext><mtext>1</mtext><mtext>2</mtext>}}{}^{\mathrm{?2}}$) proton configurations. Cranking model calculations show that the neutron excitation energies in the rotating frame agree satisfactorily with the experimental energies and that the proton excitations are expected ≈2 MeV above the experimental yrast line     

Beta-decay asymmetry and nuclear magnetic moment of 24Nam(T12 = 20 ms)

Polarized isomeric ${}^{24}\text{Na}{}^{\mathrm{m}}\text{(T}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{= 20}\text{ms}\text{, I}{}^{\mathrm{\pi }}\text{= 1}{}^{\mathrm{+}}\text{)}$ nuclei were produced by capture of polarized thermal neutrons in a NaF single crystal at room temperature. The asymmetric β-decay radition of ²⁴Na^m was used to detect nuclear magnetic resonance signals yielding the magnetic moment $\text{|μ(}{}^{24}\text{Na}{}^{\mathrm{m}}\text{)| = 1.930 (3)}\text{n.m.}$ (uncorrected).     

High spin states in 93mo populated in the (p,n) reaction

High spin states in the $\text{ν}\text{d}{}_{\mathrm{<mtext>5</mtext><mtext>2</mtext>}}\text{(π}\text{g}{}_{\mathrm{<mtext>9</mtext><mtext>2</mtext>}}{}^2$) multiplet in ⁹³Mo were investigated with the ⁹³Nb(p, n) ⁹³Mo reaction. A new isomeric state at 2430 keV with a half-life of 3.53±0.18 ns is interpreted as the lower $\text{17}\text{2}{}^{\mathrm{+}}$ member of the multiplet. A number of further states have been identified. The results are compared to previous experiments and shell model calculations.     

Glueball spectroscopy from strong coupling expansions in hamiltonian lattice QCD

Masses of all the glueballs which are created by 6- or 7-link operators are calculated to order g^?8 in pure SU(3) hamiltonian lattice gauge theory. Several low-lying states are found with masses $\text{m(0}{}^{\mathrm{++1}}\text{)～ 1.4 m}{}_{\mathrm{<mtext>s</mtext>}}\text{, m(0}{}^{\mathrm{++7}}\text{) ～ 1.7 m}{}_{\mathrm{<mtext>s</mtext>}}$ (¹ and ⁷ stand for radial excitations and m_s is the mass of the lowest 0⁺⁺ state), . These values are obtained at the point g^?2 ? 0.8, which lies near the scaling region.     

Observation of isomeric states and band structures in 107Cd

The odd-mass nucleus ¹⁰⁷Cd was investigated in the reactions ${}^{105}\text{Pd}\text{(α, 2}\text{n}\text{)}{}^{107}\text{Cd}\text{,}{}^{107}\text{Ag}\text{(d, 2}\text{n}\text{)}{}^{107}\text{Cd and}{}^{107}\text{Ag}\text{(}\text{p, n}\text{)}{}^{107}\text{Cd}$. The constructed level scheme is based on results, obtained from singles γ-ray spectra and excitation functions, from the measurements of delayed γ-rays, of γ-γ coincidences, of internal conversion electrons and of γ-ray angular distributions. Two new isomers were observed. The first one, interpreted as the $\text{h}{}_{\mathrm{<mtext>11</mtext><mtext>2</mtext>}}$ neutron state at 845.6 keV has a half-life of 67 ± 6 ns. This isomeric state is populated by a strong E2 cascade. Bands built on the other intrinsic states with spins and parities $\text{5}\text{2}{}^{\mathrm{+}}$ and $\text{7}\text{2}{}^{\mathrm{+}}$ are not strongly populated. For the second isomeric state at an excitation energy of 2679 keV a half-life of 55±4 ns was determined. This isomer is probably a three-quasiparticle state. Its configuration can be proposed as $\text{[π(}\text{g}{}_{\mathrm{<mtext>9</mtext><mtext>2</mtext>}}\text{)}{}^{\mathrm{?2}}{}_{\mathrm{8+}}\text{ν(}{}_{\mathrm{<mtext>7</mtext><mtext>2</mtext>}}\text{)}{}^1\text{]}{}_{\mathrm{<mtext>21</mtext><mtext>2</mtext>}}{}^{\mathrm{+}}$.     

(f72)7,0−2 configuration high-spin states in 60Co strongly excited in the 62Ni(d, α) reaction

The ${}^{62}\text{Ni}\text{(}\text{d}\text{, α)}{}^{60}\text{Co}$ reaction has been studied with 78 MeV vector polarized deuterons. Angular distributions of the differential cross section and vector analyzing power have been measured for strongly populated states in ⁶⁰Co up to an excitation energy of 5 MeV. The transferred orbital and total angular momenta L and J were determined from the characteristic shapes of the differential cross sections and vector analyzing powers yielding a number of new spin assignments. The J^π = 7⁺ stretched configuration was found to be distr least over nine states located at 1.51, 3.09, 3.46, 3.67, 3.78, 4.04, 4.55, 4.70 and 4.80 MeV.     

Nuclear wave functions and mesonic exchange currents in the weak transition 16O(0+) ↔ 16N(0−)

We show that any deviation from the closed-core hypothesis for ¹⁶O(0⁺, g.s.) may strongly affect the theoretical ratio of the transition probabilities for the two inverse processes: ${}^{16}\text{O(0}{}^{\mathrm{+}}\text{, g.s.}\text{) →}{}^{16}\text{N(O}{}^{\mathrm{?}}\text{, 120 keV}\text{)}$ muon-capture) and ${}^{16}\text{N(0}{}^{\mathrm{?}}\text{, 120 keV}\text{) →}{}^{16}\text{O(0}{}^{\mathrm{+}}\text{, g.s.}\text{)}$ (beta-decay). As a consequence, the possible evidence for exchange currents in this transition must be reexamined. Preliminary calculations do not exclude a still large meson exchange effect.     

Core polarization effects in the πh92 shell and g-factors of the 8+ states in 204Po and 206Po

The $\text{g-}\text{values of}\text{[(π}\text{h}{}_{\mathrm{<mtext>9</mtext><mtext>2</mtext>}}\text{)}{}^2\text{, 8}{}^{\mathrm{+}}\text{]}$ isomeric levels in ²⁰⁴Po and ²⁰⁶Po have been measured with the stroboscopic method. The results obtained are: $\text{g(}{}^{204}\text{Po}\text{) = 0.923±0.013}\text{and}\text{g(}{}^{206}\text{Po}\text{) = 0.919±0.013}$. These and other known $\text{g-}\text{factors of}\text{(π}\text{h}{}_{\mathrm{<mtext>9</mtext><mtext>2</mtext>}}\text{)}{}^{\mathrm{n}}$ states in the ²⁰⁸Pb region are compared with theoretical predictions in order to analyze the dependence of the $\text{h}{}_{\mathrm{<mtext>9</mtext><mtext>2</mtext>}}$ proton g-value on the core constitution. The variation of the g-values is systematically smaller than expected from first-order configuration mixing theory, if pure shell-model wave functions are assumed.     

Half-life of the h9/2 shell-model intruder-state isomer Au

The half-life of the $\text{9}\text{2}{}^{\mathrm{?}}$ shell-model intruder-state isomer in ¹⁸⁷Au has been measured by employing a technique in which each incoming event is tagged with a digital representation of time by means of a real-time clock. With this method we obtain a 2.3 ± 0.1 sec half-life for the $\text{h}{}_{\mathrm{<mtext>9</mtext><mtext>2</mtext>}}\text{→}\text{d}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}$ E3 isomeric transition resulting in a retardation of 50 relative to the Weisskopf single-particle estimate.     

Kerr-effect and dielectric tensor elements of magnetite (Fe3O4) between 0.5 and 4.3 eV

The complex polar Kerr effect (rotation and ellipticity) of magnetite single crystals has been measured at room temperature between 0.5 and 4.3 eV. From the magneto-optical data and the optical constants, the off-diagonal elements (?_xy) of the dielectric tensor has been derived. Three well separated magneto-optical transitions have been indentified. At about 0.75 eV one strong magneto-optical structure with a diamagnetic line shape is assigned to a $\text{3d}{}^6\text{→3d}{}^5\text{(}{}^6\text{A}{}_{\mathrm{1g}}\text{) 4s}$ transition from Fe²⁺ in octahedral sites. Two other structures with paramagnetic line shapes near 1.85 and 2.90 eV are assigned to the orbital promotion processes $\text{3d}{}^6\text{(Fe}{}^{\mathrm{2+}}{}_{\mathrm{oct}}\text{)→3d}{}^5\text{(}{}^4\text{T}{}_{\mathrm{1g}}\text{) 4s}$ and $\text{3d}{}^5\text{(Fe}{}^{\mathrm{3+}}{}_{\mathrm{tet}}\text{)→3d}{}^4\text{(}{}^5\text{T}{}_2\text{) 4s}$, respectively, which take into account Fe 3d^n?1 final state effects.     

Shell model yrast states of the N=83 nucleus 150Ho

Studies of delayed γ-rays from the reactions ¹²²Te(³²S, p3n) and ¹²¹Sb(³²S, 3n) have located high-spin excitations in ¹⁵⁰Ho up to a 92 ± 8 ns isomer at 2625 keV. The main yrast level sequence is found to agree closely with shell model predictions (based on an inert ¹⁴⁶Gd core) of level energies, isomeric half-life and deexcitation pathway for the $\text{(πh}{}_{\mathrm{<mtext>11</mtext><mtext>2</mtext>}}\text{)}{}^3\text{vf}{}_{\mathrm{<mtext>7</mtext><mtext>2</mtext>}}$ configuration.     

Lifetimes and g-factors of the 6− and 7− isomers in 66Ga and 68Ga

The 6^? and 7^? isomeric states in ⁶⁶Ga and ⁶⁸Ga at 1440.9 and 1229.6 keV, respectively, have been populated with the (¹³C, 2np) and (¹⁵N, n2p) reactions on natural Fe. The half-lives of these states have been measured to be $\text{T}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{(6}{}^{\mathrm{?}}\text{,}{}^{66}\text{Ga}\text{) = 57.3 ± 1.2}\text{ns}$ and $\text{T}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{(7}{}^{\mathrm{?}}\text{,}{}^{68}\text{Ga}\text{) = 64 ± 2}\text{ns}$. Using previous data on the hyperfine field of Ga in Fe, the g-factors of these states have been determined by means of the TDPAD method. The results are $\text{g(6}{}^{\mathrm{?}}\text{,}{}^{66}\text{Ga}\text{) = 0.129 ± 0.003}$ and $\text{g(7}{}^{\mathrm{?}}\text{,}{}^{68}\text{Ga}\text{) = 0.105 ± 0.003}$. These values are in very good agreement with the independent particle model if one assumes the and configurations and uses the empirical proton and neutron g-factors from odd-A neighboring nuclei instead of the Schmidt values. The large disagreements with experiment when Schmidt values are used show that core polarization effects are important in these nuclei.     

Absorption spectra of Ni2+ in (NH4)2Mg(SO4)2·6H2O and Co2+ in Na2Zn(SO4)2·4H2O

Optical absorption spectra of Ni²⁺ in (NH₄)₂Mg(SO₄)₂·6H₂O and Co²⁺ in Na₂Zn(SO₄)₂·4H₂O single crystals have been studied at room and liquid nitrogen temperatures. From the nature and position of the observed bands, a successful interpretation could be made assuming octahedral symmetry for both the ions in the crystals. The splitting observed for ${}^3\text{T}{}_{\mathrm{1g}}\text{(F)}$ band in Ni²⁺ and ${}^4\text{T}{}_{\mathrm{2g}}\text{(F)}$ band in Co²⁺ at liquid nitrogen temperature have been explained as due to spin-orbit interaction. The extra band observed at 16,325 cm^-1 in the case of Ni²⁺ at low temperature has been interpreted to be the superposition of vibrational mode of SO^2-₄ radical on ${}^3\text{T}{}_{\mathrm{1g}}\text{(F)}$ band. The observed band positions in both the crystals have been fitted with four parameters B, C, Dq and ζ.     

Higher order level mixing resonances on oriented nuclei

Higher order level mixing resonance have been measured on the 40 s half-life ^109mAg in Zn. It is shown that the line-width is tunable with the misalignment angle of the electric to magnetic axes, and enables precise quadruple coupling determinations. For ${}^{\mathrm{<mtext>109</mtext><mtext>m</mtext>}}\text{Ag}\text{Zn}\text{eQV}{}_{\mathrm{zz}}\text{/μ = 3.08(2)}$ T has established.     

A j-forbidden isomeric transition in 204At

An isomeric 587.3 keV transition was investigated using several target-ion combinations: ¹⁹⁷Au+¹²C, ¹⁹³Ir+¹⁶O and ¹⁹⁶Pt+¹⁵N. From the measured excitation functions for the ${}^{193}\text{Ir}\text{(}{}^{16}\text{O, x}\text{n}\text{)}{}^{\mathrm{<mtext>209–</mtext><mtext>x</mtext>}}$ At reaction it follows that this transition belongs to ²⁰⁴At. The isomeric level is ascribed to the 10^? state of the configuration π(h_{$\text{9}\text{2}$})³_{$\text{9}\text{2}$}ν(i_{$\text{13}\text{2}$})^?1.