The second 132+ state in 19F

A cryogenically pumped gas target has been used to study resonances in the ¹⁵N(α, γ)¹⁹F reaction for E_α = 5.1 to 8.6 Mev. Gamma-ray intensity and angular distribution measurements for a resonance at E_α = 8.105 Mev, corresponding to a state at 10.411 MeV in ¹⁹F, restrict the spin and parity of the state to $\text{11}\text{2}{}^{\mathrm{+}}$ or $\text{13}\text{2}{}^{\mathrm{+}}$. Comparison with shell model calculations indicate that the state is a strong candidate for the second $\text{13}\text{2}{}^{\mathrm{+}}$ (2s, 1d)³ level in ¹⁹F.     

Lifetime and g-factor results for the 132− 1985 keV level in 91Nb and the 152− 2288 keV level in 91Zr

Lifetime and g-factor measurements have been made with pulsed beam-γ time-differential techniques using the ⁸⁹Y(α, 2n)⁹¹Nb and ⁸⁸Sr(α, n)⁹¹Zr reactions. A mean lifetime τ = 14.4 ± 0.5 nsec and a g-factor of 1.26 ± 0.04 were obtained for the $\text{13}\text{2}{}^{\mathrm{?}}$ 1985 keV level in ⁹¹Nb and τ = 41.9 ± 1.2 nsec and g = 0.70 ± 0.01 were obtained for the $\text{15}\text{2}{}^{\mathrm{?}}$ 2288 keV level in ⁹¹Zr. These results are compared to theoretical calculations for $\text{(π}\text{g}{}_{\mathrm{<mtext>9</mtext><mtext>2</mtext>}}\text{)}{}^2\text{(π}\text{p}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{)}$ and $\text{(π}\text{g}{}_{\mathrm{<mtext>9</mtext><mtext>2</mtext>}}\text{)(π}\text{p}\text{1}\text{2}\text{)(v}\text{d}{}_{\mathrm{<mtext>5</mtext><mtext>2</mtext>}}\text{)}$ configurations in ⁹¹Nb and ⁹¹Zr, respectively.     

Leptonic decays of the Ω−

Branching ratios, widths, and lepton energy spectra are derived for the leptonic decays of the $\text{Ω}{}^{\mathrm{?}}$ into β⁰ and $\text{β}{}^{01}$. The calculations are made by hypothesizing that higher-order multipoles in an expansion of the baryon current are zero. The axial vector coupling is determined using the bag model.     

Decays of high spin Δ1 and N1 resonances in the quark model

Starting with a set of harmonic oscillator wavefunctions, we calculate partial decay rates of excited $\text{Δ}{}^1$ and $\text{N}{}^1$ states into a nucleon with single pion emission. Good agreement with values estimated from data is obtained for N ≤ 6, thus indicating that the simple quark model is reasonable over a much wider range than expected. The calculated decay rates of the even higher states depend more sensitively on the finer details of the nucleon wavefunction.     

Magnetic moment and half-life of the isomeric 112− state in 107Cd

An isomeric level in ¹⁰⁷Cd at 845 keV populated by the reactions ¹⁰⁷Ag(p, n), ¹⁰⁶Cd(d, p) and ¹⁰⁴Pd(α, n) has been observed. The half-life of this state is $\text{T}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{= 77(7)}\text{ns}$, and the spin and parity are $\text{I}{}^{\mathrm{\pi }}\text{=}\text{11}\text{2}{}^{\mathrm{?}}$. The magnetic moment has been determined by the pulsed beam time-differential perturbed angular distribution method (DPAD) to be μ = ?1.012(12) n.m.     

Magnetic moments of Jπ = 192− mirror states in 43Ti and 43Sc

The time-differential perturbed angular distribution method was used to determine the g-factors of the $\text{(}\text{f}{}_{\mathrm{<mtext>7</mtext><mtext>2</mtext>}}\text{)}{}^3\text{19}\text{2}{}^{\mathrm{?}}$ states in ⁴³Ti and ⁴³Sc. The results for the mass 43 mirror pair are: ${}^{43}\text{Ti}\text{: g = 0.760 ± 0.001, T}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{, = 560 ± 6}\text{ns}$, ${}^{43}\text{Sc}\text{: g = 0.3286± 0.0007, T}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{= 473 ± 5}\text{ns}$. Considering in addition the magnetic moments in A = 41 and 42, it is suggested that the deformed states considered by Johnstone and Castel and by Erikson are responsible for the observed large deviations from the Schmidt values.     

Calculations of nonleptonic Ω− decay branching ratios

Nonleptonic $\text{Ω}{}^{\mathrm{?}}$ decay branching ratios have been calculated using the Weinberg-Salam model with QCD corrections and the MIT bag model. The whole scheme is equivalent to that which works well for nonleptonic hyperon decays. The calculated values are in qualitative and even rough quantitative with experimental data.     

The gyromagnetic ratio of the 208 KeV 32− state of 199Hg

The ion implantation perturbed angular correlation technique was used to measure the g-factor of the $\text{3}\text{2}{}^{\mathrm{?}}$ state at 208 keV of ¹⁹⁹Hg recoiling into iron. A value $\text{g(}\text{3}\text{2}{}^{\mathrm{?}}\text{) = 0.35±0.11}$ was deduced from the data. This result is in agreement with predictions of an extended core excitation model.     

Study of the reaction νp → μ+pπ−

We present data on the reaction $\text{ν}\text{p → μ}{}^{\mathrm{+}}\text{pπ}{}^{\mathrm{?}}$ from an exposure of the Fermilab 15 ft hydrogen bubble chamber. The channel cross section for $\text{5}\text{GeV}\text{< E}{}_{\mathrm{<mtext>\nu </mtext>}}\text{< 70}\text{GeV and}\text{M(}\text{p}\text{π}{}^{\mathrm{?}}\text{) < 1.9}\text{GeV is}\text{σ = (27 ± 5) × 10}{}^{\mathrm{?40}}\text{cm}{}^2$. This cross section is dominated by the $\text{I =}\text{1}\text{2}$ production amplitude.     

Nuclear magnetic moment of the 3.9 s112− isomer 193mAu

The magnetic hyperfine splitting ν_M = |gμ_NB_HF/h| of ${}^{\mathrm{<mtext>193</mtext><mtext>m</mtext>}}\text{Au}\text{(j}{}^{\mathrm{\pi }}\text{=}\text{11}\text{2}{}^{\mathrm{?}}\text{, E = 290}\text{keV}$; $\text{T}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{= 3.9}\text{s}\text{)}$ as a dilute impurity in Ni has been measured with nuclear magnetic resonance on oriented nuclei as 226.4(2) MHz. With the known hyperfine field B_HF = ?264.4(3.9) kG corrected for hyperfine anomalies the g-factor and magnetic moment of ^193mAu are deduced to be |g| = 1.123(17) and |μ| = 6.18(9) μ_N.     

On the reactions pp ↔ dπ+

The total cross section for π⁺d → pp and the angular distribution and asymmetry parameters for the inverse reaction $\text{p}\text{p}\text{→ π}{}^{\mathrm{+}}\text{d}$ have been calculated with different models for the pion absorption (and production) operator and several sets of nuclear wave functions. The absorption operator includes both single-nucleon and two-nucleon operators. Fair agreement can be achieved with all empirical parameters at low energies, but significant discrepancies occur at high energies. The results are very sensitive to the model for the nucleon-nucleon interaction used to generate the wave functions.     

Lifetimes of the low-lying 72− states in 113, 115Cd

The half-lives of the $\text{7}\text{2}{}^{\mathrm{?}}$ states at 522.6 and 393.9 keV in ¹¹³Cd and ¹¹⁵Cd have been determined to be 0.322±0.012 and 0.75± 0.03 ns, respectively. Values of the $\text{B(}\text{E}\text{2,}\text{7}\text{2}{}^{\mathrm{?}}\text{→}\text{11}\text{2}{}^{\mathrm{?}}$) and the energy difference in odd Cd (A = 113–119) are compared with those in neighbouring even Cd. The level properties are interpreted in the framework of the triaxial rotor model.     

The level scheme of 135Pr: Prolate deformation of the 112− isomer

The level scheme of ¹³⁵Pr has been investigated by means of off-beam γ-ray and conversion electron measurements as well as by methods of in-beam γ-spectroscopy. We measured γ-ray and conversion electron singles spectra, off-beam and in-beam γγ coincidences and γ-angular distributions. From the experimental data a detailed scheme of 22 excited levels for ¹³⁵Pr has been constructed. In addition to members of the decoupled band based on the $\text{11}\text{2}{}^{\mathrm{?}}$ state six further negative parity states were identified. These states are strongly populated in the β-decay of a $\text{9}\text{2}$ isomer in the parent nucleus ¹³⁵Nd. A comparison of all the negative parity states with predictions of the alignment coupling model showed a nearly quantitative agreement, if softness of the core is taken into account. In this case, a prolate deformation with a deformation parameter β ≈ 0.13 was obtained for the $\text{11}\text{2}{}^{\mathrm{?}}$ isomer in ¹³⁵Pr.     

Some properties of the (ψψ)2 model in two dimensions

We show that the two-dimensional $\text{(}\text{ψ}\text{ψ)}{}^2$ model is, for N = 3, equivalent to the supersymmetric sine-Gordon equation, and for N = 4, equivalent to two decoupled sine-Gordon systems. In addition, we argue that the kinks of this model are isospinors, and we construct some of the higher conservation laws that are responsible for the exact solubility of this system.     

Medium-spin levels and the character of the 20.4 ns 132+ isomer in 145Gd

Levels of the N = 81 nucleus ¹⁴⁵Gd have been investigated by in-beam γ-ray and conversion electron spectroscopy with the ¹⁴⁴Sm(³He, 2n) reaction. Fourteen new low- and medium-spin states between 1.0 and 2.4 MeV excitation, the known yrast levels up to spin $\text{21}\text{2}{}^{\mathrm{+}}$, five other high-spin non-yrast states and a new 20.4 ns $\text{13}\text{2}$ isomer at 2200.2 keV in ¹⁴⁵Gd have been observed. The isomer decays via a fast 927.3 keV E3 transition with B(E3) = 48 ± 7 W.u. Another weaker decay branch is a mixed, strongly hindered E1 + M2 + E3 transition to the $\text{v}\text{h}{}^{\mathrm{?1}}{}_{\mathrm{<mtext>11</mtext><mtext>2</mtext>}}$ state. We propose an octupole $\text{v}\text{f}{}_{\mathrm{<mtext>7</mtext><mtext>2</mtext>}}\text{j}{}^{\mathrm{?2}}\text{× 3}{}^{\mathrm{?}}$ main configuration for the isomer, analogous to the 997 keV $\text{13}\text{2}{}^{\mathrm{+}}$ isomer in ¹⁴⁷Gd. The levels of ¹⁴⁵Gd are discussed on the basis of the spherical shell model.     

A selection rule on angular momentum transfer in reactions of the type 0−12+→1−32+

An analysis of 50 experimental data on polarization and correlations of polarization in the reactions $\text{π}\text{N}\text{→?Δ, ωΔ}\text{and KN}\text{→}\text{K}{}^1\text{Δ, ?Σ}{}^1\text{, ΦΣ}{}^1$ strongly suggests a pure ΔJ=1 transition at the baryon vertex. A plot for testing graphically the linear constraints of the selection rule ΔJ=1 is proposed.     

Observation of structure in p̄p → π0π0

We present a partial wave amplitude analysis of the differential cross sections for p?p → π⁰π⁰ at 25 energies from 2.12 to 2.43 GeV. The results suggest the presence of a J^PCI^G = 2⁺⁺0⁺ resonance at 2.15 GeV. An isospin decomposition of p?p → π⁺π^- is also presented.     

A light neutral intermediate vector boson without large e+e−→ μ+μ− asymmetries

An effective SU(2)×U(1)×U(1)' electroweak theory is shown to permit the occurence of a pair of neutral intermediate vector bosons with masses 40 GeV?m_light?70 GeV, m^W.S._Z⁰<m_heavy?100 GeV. Neutrino neutral current interactions are shown to be the same as in the standard electroweak model, and e⁺e^?→μ⁺μ^? forward-backward asymmetries are within experimental bounds for m_light?40 GeV.     

Sign of 12− resonance contributions to parity-violating NNϱ couplings

The sign of $\text{1}\text{2}{}^{\mathrm{?}}$ resonance pole contributions to the parity-violating NN_? weak vertex has been estimated using the MIT bag model. The signs and orders of magnitude of the effective parity-violating NN_? couplings agree with theoretical analyses based on SU(6)_W and with experimental data.     

Search for finite-mass neutrinos in the decay π+→μ+vμ

If neutrinos possess non-zero mass, pion decay might have small decay branches to neutrino states with large masses. We have searched for such branches in the decay of pions produced at the Indiana University Cyclotron. The energy spectrum of decay muons shows no evidence for such neutrino branches and if these decays do exist, their branching ratios must be less than 10^?2 to 10^?3 for neutrino masses in the ranFge 7–33 MeV.