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High-spin states in ^167,168Hf and ^{170, 171}W have been excited by the reactions ${}^{159}\text{Tb}\text{(}{}^{14}\text{N}\text{, x}\text{n}\text{)}{}^{\mathrm{173\; ?\; x}}\text{Hf and}{}^{155}\text{Gd}\text{(}{}^{20}\text{Ne}\text{, x}\text{n}\text{)}{}^{\mathrm{175\; ?\; x}}\text{W}$. The yrast bands have been observed up to $\text{J}{}^{\mathrm{\pi }}\text{=}\text{49}\text{2}{}^{\mathrm{+}}$ in ¹⁶⁷Hf, J^π = 28⁺ in ¹⁶⁸Hf, $\text{J}{}^{\mathrm{\pi }}\text{=}\text{45}\text{2}{}^{\mathrm{+}}$ in ¹⁷¹W and J^π = 22⁺ in ¹⁷⁰W. Both even-even nuclei display a strong backbend around J^π = 14⁺, whereas ¹⁶⁷Hf shows an upbend at ω ～- 0.33 MeV and ¹⁷¹W exhibits a progressive gain in aligned angular momentum above ω ～- 0.26 MeV. At even higher rotational frequencies, bridges have been found in the central valleys of the γ-γ correlation matrices at ω ～- 0.42 and 0.52 MeV for the Hf isotopes and ω ～- 0.45 and 0.47 MeV for the W isotopes. Deduced moments of inertia for the Hf isotopes using the correlation data show a smooth increase up to about the rigid-sphere value at ω ～- 0.5 MeV. The data are satisfactorily accounted for by cranked shell-model calculations. In particular, a qualitative interpretation is given for the experimentally observed systematic difference in the strength of the interaction potential for the N = 95 and N = 97 isotopes of Hf and W.     

The A-dependence of J/ψ-particle inclusive distributions

The differential cross sections $\text{d}\text{σ}\text{d}\text{x}$ and $\text{d}\text{σ}\text{d}\text{p}{}_{\mathrm{t}}{}^2$ of inclusive J/ψ production by 43 GeV/c π^? off Be, Cu and W nuclei have been measured. Fitting $\text{d}\text{σ}\text{d}\text{p}{}_{\mathrm{t}}{}^2\text{～ A}{}^{\mathrm{\alpha }}\text{(p}{}_{\mathrm{t}}{}^2\text{)}$ we observed the increase of α with p_t².     

Core polarization and magnetic moment of some odd-mass nuclei around N = 50

The effect of core polarization on the magnetic moment is studied for odd-mass nuclei around $\text{N = 50:}{}^{\mathrm{85,\; 87}}\text{Kr}\text{,}{}^{\mathrm{87,\; 89}}\text{Sr}\text{,}{}^{91}\text{Zr and}{}^{89}\text{Y}$. The calculation is done in the framework of the modified Tamm-Dancoff approximation (MTDA). The ground-state wave function is calculated using the configuration space of p?f$\text{\$}\text{?}$and ?dg$\text{\$}\text{?}$shells. The core polarization correction to the magnetic moment is considerable for all the nuclei, except ⁸⁹Y, and it depends upon the particular form of the interaction. For ⁸⁹Y the last odd proton is in the $\text{p}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ level and the smallness of the correction is supported by the observed value of the magnetic moment.     

The magnetic moment of 67Zn and the shielding of zinc ions by water

The ratio of the Larmor frequencies of ⁶⁷Zn and ³⁷Cl has been measured by the NMR method and a magnetic moment has been calculated for ⁶⁷Zn. The shielding constant for the hydrated zinc ion has been evaluated: $\text{σ}{}^1\text{=}\text{?(6.9±0.1)×10}{}^{\mathrm{?4}}$.     

Spectroscopy of 75Se studied with the 72Ge(α, nγ) reaction

States in ⁷⁵Se have been excited by the reaction ⁷²Ge(α, n)⁷⁵Se and a level scheme built up from the observed γ-ray spectra. Gamma-ray angular distribution measurements have been analysed to yield spin assignments, mixing ratios and branching ratios. Comparison of the positive parity spectrum with the levels predicted by a Coriolis coupling calculation shows good agreement. In particular the model can successfully predict the occurrence of “anomalous” states with $\text{J}{}^{\mathrm{\pi }}\text{=}\text{5}\text{2}{}^{\mathrm{+}}\text{and}\text{7}\text{2}{}^{\mathrm{+}}$ which lie close to the $\text{9}\text{2}{}^{\mathrm{+}}$ state in this nucleus, and which ar general feature of many neighbouring nuclei. Calculated E2 and M1 transition rates among these levels agree with available experimental data to within a factor of two. A strong case can therefore be made for regarding the low-lying levels in ⁷⁵Se as arising from an odd neutron coupled to a deformed prolate core.     

Rotational bands in 195, 197Tl

High-spin states in ^{195, 197}Tl have been populated with (α, xn) reactions and studied by means of in-beam γ-ray and e^? spectroscopic methods. Complementary studies of the decay of ^{195, 197}Pb to ^{195, 197}Tl have been carried out. Several new features have been observed in these nuclei. The $\text{9}\text{2}{}^{\mathrm{?}}$ bands of ^{195, 197}T1. extended to $\text{27}\text{2}{}^{\mathrm{(?)}}$ and $\text{29}\text{2}{}^{\mathrm{(?)}}$, respectively, show a quenching of energy spacings between the $\text{23}\text{2}{}^{\mathrm{?}}$, $\text{25}\text{2}{}^{\mathrm{?}}$, $\text{27}\text{2}{}^{\mathrm{(?}}$ and $\text{29}\text{2}{}^{\mathrm{(?}}$ states. This has been interpreted as resulting from the coupling of a $\text{h}{}_{\mathrm{<mtext>9</mtext><mtext>2</mtext>}}$ proton to the ($\text{π}\text{h}{}^{\mathrm{?2}}{}_{\mathrm{<mtext>11</mtext><mtext>2</mtext>}}\text{)}{}_{\mathrm{8+,\; 10+}}$ configurations in the core nuclei ^{194, 196}Hg. Furthermore, positive-parity bands based on $\text{15}\text{2}{}^{\mathrm{+}}$ states were established up to the $\text{35}\text{2}{}^{\mathrm{(+)}}$ and $\text{29}\text{2}{}^{\mathrm{(+)}}$ states in ^{195, 197}Tl respectively. Probably these bands originate from the coupling of a h${}_{\mathrm{<mtext>9</mtext><mtext>2</mtext>}}$ proton to a broken neutron pair. This pair consists of a rotation-aligned $\text{i}{}_{\mathrm{<mtext>13</mtext><mtext>2</mtext>}}$ neutron and a low-j neutron in the $\text{P}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$, $\text{P}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}$ or $\text{f}{}_{\mathrm{<mtext>5</mtext><mtext>2</mtext>}}$ shell. It is known to constitute the 5^? bands in ^{194, 196}Hg.     

The nuclear magnetic moment of 71As and 72As

Nuclear magnetic resonance of oriented ⁷¹As and ⁷²As nuclei has been observed in an iron host lattice at low temperatures. The resonance frequencies are v_l = 174.96(10) MHz and 282.00(11) MHz respectively for zero external field. Using B_h.f.(FeAs) = 342.9(3) kG the g-factors of the two isotopes are derived as $\text{g(}{}^{71}\text{As}\text{) = (+)0.6694(7)}\text{and}\text{g(}{}^{72}\text{As) = (?)1.0789(11)}$. Combining nuclear orientation data with these results the spin of ⁷¹As has been confirmed as $\text{I =}\text{5}\text{2}$. The magnetic moments of the $\text{5}\text{2}{}^{\mathrm{?}}$ and 2^? states in the As isotopes are discussed in the framework of the shell model with configuration mixing.     

Evidence for two-step processes in reactions with spherical nuclei

Experimental evidence for two-step processes in reactions with spherical nuclei is obtained from a study of ⁵⁴Fe(p, d)⁵³Fe angular distributions for low-lying $\text{9}\text{2}{}^{\mathrm{?}}$ and $\text{11}\text{2}{}^{\mathrm{?}}$ states. Predictions of the coupled-channel Born approximation give excellent agreement with the data.     

Measurement of the magnetic moment of 39Ca by use of a polarized proton beam and NMR detection

Polarized β-emitting ${}^{39}\text{Ca}\text{(I}{}^{\mathrm{\pi }}\text{=}\text{3}\text{2}{}^{\mathrm{+}}$, $\text{T}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext><mtext>=0.87</mtext>}}\text{s)}$ nuclei were produced in the reaction ${}^{39}\text{K(π|p, n)}{}^{39}\text{Ca}$ in thick polycrystalline targets of KBr, KCaBr₃, and KCaI₃ which served as hosts for the ${}^{39}\text{Ca}$ nuclei. The net polarization transferred to the ${}^{39}\text{Ca}$ nuclei was detected by measuring the asymmetry in the β-decay. The magnetic dipole moment of ${}^{39}\text{Ca}$ was measured by NMR detection. Including a diamagnetic correction we obtain ω=1.0216(2) nm.     

Coulomb excitation and lifetime measurements of the 21+ states in 76, 82, 84Kr

A mean lifetime of τ = 35 ± 3 ps of the 2⁺₁ state in ⁷⁶Kr has been measured with the recoil distance method via the reaction ⁶³Cu(¹⁹F, α2n)⁷⁶Kr. The B(E2; 0⁺₁ → 2⁺₁) values and lifetimes of the 2⁺₁ states in ^{82, 84}Kr have been measured via Coulomb excitation using the 1.4 MeV/A UNILAC krypton beams. The intensities of the γ-rays from the Coulomb excited levels of ^{82, 84}Kr were interrelated with those of the target nuclei ²⁷Al, ^{64, 66}Zn and ^{70, 72, 74, 76}Ge and yielded the values $\text{B(}\text{E}\text{2; 0}{}^{\mathrm{+}}{}_1\text{→ 2}{}^{\mathrm{+}}{}_1\text{= 0.255±0.009}\text{and}\text{0.122 ± 0.005}\text{e}\text{2 ·}\text{b}\text{2}\text{for}{}^{\mathrm{82,\; 84}}\text{Kr}$, respectively. In turn, these B(E2) values and the (E2; 0⁺₁ → 2⁺₁ values of the even Ge and Zn isotopes from the literature were used in a Doppler-shift attenuation analysis to obtain experimentally lacking electronic stopping power for Kr ions slowing down in Al, Zn and Ge. for Ge ions in Ge and for Zn ions in Zn.     

The level structure of 184W FROM THE β− decay of 184Ta

Levels of ¹⁸⁴W populated in the decay of 8.7 h ¹⁸⁴Ta have been studied by a variety of experimental techniques. As a result of β and γ-ray energy and intensity determinations and extensive β-γ and γ-γ coincidence measurements, a detailed ¹⁸⁴Ta decay scheme accommodating more than 99.5% of the decay intensity has been established. Intense β-ray groups of end-point energies 1165±26 and 1123±26 keV populate levels in ¹⁸⁴W at 1699 and 1746 keV, which de-excite predominantly to the 8.3 μs isomeric level at 1285 keV, recently identified as the $\text{1}\text{2}{}^{\mathrm{?}}\text{[510]ν?}\text{11}\text{2}{}^{\mathrm{+}}\text{[615]ν K}{}^{\mathrm{\pi }}\text{= 5}{}^{\mathrm{?}}$ band origin. The 1699 keV level also de-excites to members of a $\text{1}\text{2}{}^{\mathrm{?}}\text{[510]ν?}\text{7}\text{2}\text{[503]ν K}{}^{\mathrm{\pi }}\text{= 3}{}^{\mathrm{+}}$ band based at 1425 keV. New information about the properties of the γ-vibrational and K = 2 octupole bands in ¹⁸⁴W is presented and the possible configurations of the levels directly populated in the β^? decay are discussed. The configuration $\text{7}\text{2}{}^{\mathrm{+}}\text{[404]π ?}\text{3}\text{2}{}^{\mathrm{?}}\text{[512]ν K}{}^{\mathrm{\pi }}\text{= 5}{}^{\mathrm{?}}$ is indicated for the ¹⁸⁴Ta ground state.     

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).     

Direct evidence for W exchange in charmed meson decay

Using the ARGUS detector at DORIS II, we have observed a signal of 36.7±8.0 events in the decay channel D⁰→K_s⁰φ. In the same data sample, we have observed the well established decay D⁰→K_s⁰π⁺π^?, and find the ratio, $\text{Br(D)}{}^0\text{→}\text{K}{}_{\mathrm{<mtext>s</mtext>}}{}^0\text{φ)}\text{Br(D)}{}^0\text{→}\text{K}{}_{\mathrm{<mtext>s</mtext>}}{}^0\text{π}{}^{\mathrm{+}}\text{π}{}^{\mathrm{?}}\text{)}$, to be 0.186±0.052. The substantial value of (0.99±0.32±0.17)% then derived for the branching ratio for $\text{D}{}^0\text{→}\text{K}{}^0\text{φ}$ gives direct evidence that W exchange contributes D⁰ decay.     

Coherent production of multimeson final states on A ∼ 20 nuclei by K− of 5.5, 10.0, 12.7 GeV

Coherent production of $\text{K}\text{π,}\text{K}\text{2π}\text{and}\text{K}\text{3π}$ final states from A ～ 20 nuclei by K^? beams of 5.5, 10.0 and 12.7 GeV is analyzed. Final states with ? 2π^O are included. Coherent $\text{K}\text{π}$ production occurs (although forbidden via 0⁺ exchange) and is dominated by the $\text{K}$¹ (890). The shape of the t distribution, the alignment of the produced meson and the ratio of the cross section on nuclei to that on hydrogen are consistent with optical model predictions assuming that $\text{K}$¹ (890) are produced on single nucleons by exchange of isoscalar trajectories of natural parity (J^P = 1^?, 2⁺, etc.) and that the $\text{K}$¹ (890) absorption in nuclear matter equals that of the K^?. Coherent $\text{K}\text{ππ}$ production (allowed via 0⁺, 1^?, 2⁺, etc. exchange) is dominated by the Q phenomenon. A Dalitz plot and angular correlation analysis yields values for $\text{K}\text{?/}\text{K}{}^1\text{π}$ fractions, and shows that $\text{J}{}^{\mathrm{P}}\text{= 1}{}^{\mathrm{+}}\text{S-wave}\text{K}{}^1\text{π}$ dominates the coherently produced Q. The helicity of the Q is found to be compatible with 0. The Q^? -nucleaon total cross section is estimated to be 0.98_?0.37⁺⁰²⁴ times the $\text{K}$^? -nucleon total cross section from a comparison of the coherent Q-production cross section with corresponding hydrogen cross sections at 10 and 12.7 GeV. We observe coherent production of $\text{K}$ω. The ration $\text{K}\text{ω/}\text{K}\text{ππ}$ coherently produced in the Q mass region is (4 ± 1)%. Coherent production of $\text{K}{}^{\mathrm{?}}\text{π}{}^{\mathrm{+}}\text{π}{}^{\mathrm{?}}\text{and}\text{K}{}^{\mathrm{<mtext>O</mtext>}}\text{π}{}^{\mathrm{+}}\text{π}{}^{\mathrm{?}}\text{π}{}^{\mathrm{<mtext>O</mtext>}}$ is observed in the L region. Coherent production is not observed in the K4π channels.     

Rotational bands in odd hafnium nucleides

Rotational bands up to high-spin members in odd-neutron Hf nucleides are studied by in-beam spectroscopy using (α, xn) reactions on isotopically enriched Yb targets. The $\text{1}\text{2}{}^{\mathrm{?}}$ [521], $\text{5}\text{2}{}^{\mathrm{?}}$ [512], and the $\text{7}\text{2}{}^{\mathrm{+}}$ mixed positive-parity (mainly $\text{7}\text{2}{}^{\mathrm{+}}$ [633]) bands were observed in ¹⁷³Hf and ¹⁷⁵Hf while the $\text{7}\text{2}{}^{\mathrm{?}}$ [514], $\text{9}\text{2}{}^{\mathrm{+}}$ (mainly $\text{9}\text{2}{}^{\mathrm{+}}$[624]), and the $\text{3}\text{QP}\text{(K =}\text{23}\text{2}$⁺) bands were studied in ¹⁷⁷Hf. The analysis of the band structure within the Nilsson model is extended to also include adjacent odd Hf nuclei making it possible to follow these bands through five isotopes of Hf.     

Strong absorption model for the (α, 2α) reaction

The (α, 2α) reaction has been studied in the “diffraction model” for ¹⁶O, ²⁹Mg, ⁴⁰Ca and ⁶⁶Zn nuclei at 90 MeV incident energy. Using $\text{R}{}_{\mathrm{<mtext>c</mtext>}}\text{= 1.15(A}{}^{\mathrm{<mtext>1</mtext><mtext>3</mtext>}}\text{+4}{}^{\mathrm{<mtext>1</mtext><mtext>3</mtext>}}\text{)}\text{fm}$ for the strong absorption radius and Δ = 0.06R_c for the diffuseness of the absorbing surface the spectroscopic factors are extracted. These spectroscopic factors are in excellent agreement with the theoretical values. The positions of the minima and second maxima are also reproduced.     

Decay of the mirror nuclide 45V

The β⁺ decay of ⁴⁵V $\text{(J}{}^{\mathrm{\pi }}\text{, T=}\text{7}\text{2}{}^{\mathrm{?}}\text{,}\text{1}\text{2}\text{)}$ has been observed. The half-life was found to be 539 ± 18 ms; in addition to the superallowed transition to the mirror state (⁴⁵Ti ground state), it exhibits a (4.3 ± 1.5)% allowed branch to the $\text{5}\text{2}{}^{\mathrm{?}}$ state at 40.1 keV in ⁴⁵Ti. Decay data for the complete $\text{f}{}_{\mathrm{<mtext>7</mtext><mtext>2</mtext>}}$ shell series of mirror nuclei are presented.     

The 6Li-induced three-nucleon transfer reaction on 40Ca

Analog (fp)³ states preferentially excited in the ${}^{40}\text{Ca}\text{(}{}^6\text{Li,t}\text{)}{}^{43}\text{Ti}$ and the ${}^{40}\text{Ca}\text{(}{}^6\text{Li}\text{, τ)}{}^{43}\text{Sc}$ reactions have been identified in the mass 43 mirror nuclei. A simple zero-range DWBA calculation made with a cluster form factor gives good agreement with the measured angular distributions, but spectroscopic strengths deduced for mirror levels do not agree. The 3p-0h states are excited with a rather uniform cross section not strongly correlated with spins.