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.     

Generalization of the Kohn—Sham ϱ43 result for excited states

A form is derived for the “exchange energy” in the density functional theory of excited states.     

Hyperfine interaction in the 4D32 and the 4D52 levels of sodium

We have excited the $\text{4D}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}$ and $\text{4D}{}_{\mathrm{<mtext>5</mtext><mtext>2</mtext>}}$ levels of sodium using Doppler-free two-photon excitation. By measuring the polarization rate in zero magnetic field of the fluorescence lines, we have deduced the following values for the hyperfine interaction $\text{|A(}\text{4D}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}\text{) | =}\text{0.23 ± 0.12 MHz}$ and $\text{|A(}\text{4D}{}_{\mathrm{<mtext>5</mtext><mtext>2</mtext>}}\text{)| <}\text{0.28 MHz}$. The value of $\text{A(}\text{4D}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}\text{)}$ is in disagreement with the one reported by Schenk and Pillof.     

The (1f72)2 states in 34S

A distorted wave analysis of the ³²S(t,p) ³⁴S reaction reveals that the 0⁺ state at 5.86 MeV, the 2⁺ state at 7.80 MeV and the 4⁺ state at 8.42 MeV are the principal components of the $\text{(1}\text{f}{}_{\mathrm{<mtext>7</mtext><mtext>2</mtext>}}{}^2$, T = 1 multiplet.     

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.     

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.     

The d52 analog strength in 59Cu

Isobaric analog states of the strongest $\text{d}{}_{\mathrm{<mtext>5</mtext><mtext>2</mtext>}}$ parent states in ⁵⁹Ni were investigated in the reaction ⁵⁸Ni + p. Proton spectroscopic factors were derived whose sum was found to be in good agreement with the sum of the parent strengths. The absolute transition probability of the E1 γ-decay populating the ⁵⁹Cu ground state was estimated and compared with single-particle predictions.     

Upper limits on D0-D0 mixing and BB production from muon-nucleon scattering

In deep inelastic interactions of 200 GeV muons with a carbon target, we have found 17 events of the type μ^±N→μ^±μ^?μ^?X (“wrong-sign” dimuons). We derive upper limits of 1.2% (90% CL) on $\text{D}{}^0\text{-}\text{D}{}^0$ transitions (mixing) or, alternatively, of 9 pb (90% CL) cross section for $\text{B}\text{B}$ pair production as possible sources of such events.     

The l-forbidden 3p32 → 2f52M1 transition in 207Pb

The branching ratio for the transition from the 0.90 MeV second excited to the 0.57 MeV first excited state in ²⁰⁷Pb has been measured to be (0.59 ± 0.09)%. The corresponding B(M1) exceeds recent theoretical predictions.     

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.     

f72 neutron occupancies in the Ca isotopes

Methods of obtaining nucleon occupancies from total energy-weighted sum rules for spectroscopic factors are described and applied to $\text{f}{}_{\mathrm{<mtext>7</mtext><mtext>2</mtext>}}$ neutron transfer data for Ca isotopes. The $\text{f}{}_{\mathrm{<mtext>7</mtext><mtext>2</mtext>}}$ neutron occupancies obtained are consistent with shell model expectations and, for ⁴¹Ca and ⁴³Ca, with values previously obtained from an analysis using non-energy-weighted sum rules.     

The g-factor of the 132+ state in 207Po and the mesonic contribution to the moment of the i132-neutron

The magnetic moment of the $\text{13}\text{2}{}^{\mathrm{+}}$ state in ²⁰⁷Po was determined to be μ = ?0.910 ± 0.014 n.m. An analysis of this value and other known moments of $\text{i}{}_{\mathrm{<mtext>13</mtext><mtext>2</mtext>}}$ neutron states around ²⁰⁸Pb supports the existence of a mesonic contribution of at least ?0.3 n.m. to the moment.     

Magnetic moments of (νi132)−n isomers in neutron-deficient lead isotopes

The magnetic moments of the 12⁺ isomers in ^{192, 196, 198, 200, 206}Pb and of the $\text{33}\text{2}{}^{\mathrm{+}}$ isomer in ²⁰⁵Pb have been measured using the PAD technique. The results for the g-factors are: g(192) = ?0.173(2), g(196) = ?0.1600(15), g(198) = ?0.1552(15), g(200) = ?0.1512(15), g(206) = ?0.1496(18), and g(205) = ?0.148(5). As all states have a rather pure $\text{(νi}{}_{\mathrm{<mtext>13</mtext><mtext>2</mtext>}}\text{)}{}^{\mathrm{?n}}$ configuration, the values reflect directly the $\text{νi}{}_{\mathrm{<mtext>13</mtext><mtext>2</mtext>}}$ orbital. They show a decrease towards the more neutron-deficient isotopes attributed to the reduced core polarisation as a result of decreasing occupation of the $\text{i}{}_{\mathrm{<mtext>13</mtext><mtext>2</mtext>}}$ neutron shell. The measured systematics are discussed regarding core polarisation, mesonic corrections, and small admixtures of core-excited states to the $\text{i}{}_{\mathrm{<mtext>13</mtext><mtext>2</mtext>}}$ wave function.     

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.     

Differential cross section zeros for the process NN → ππ

We describe a method for examining the differential cross section zeros for the process spin $\text{(}\text{1}\text{2}\text{+}\text{1}\text{2}\text{) →}\text{spin}\text{(0 + 0)}$. This is illustrated using the reaction $\text{p}\text{p}\text{→ π}{}^{\mathrm{?}}\text{π}{}^{\mathrm{+}}$, where three dominant meson spin states are shown to exist in the mass range 2020 to 2580 MeV/c².     

ESR spectra of the OD radical in the 2Π32, J = 32 state, v = 0–5 levels

The paramagnetic resonance absorption spectrum of the OD radical in the excited vibrational levels up to v = 5 of the ground ${}^2\text{Π}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}$, $\text{J =}\text{3}\text{2}$ state has been observed at X-band frequencies. The theory of the Zeeman effect of a paramagnetic ²Π state of a light diatomic molecule has been applied to analyze the spectrum. The Λ-doubling frequencies, the molecular g factors, coefficients of the second order Zeeman effect, and the hyperfine interaction constants were determined for each of the vibrational levels. The experimental results agree reasonably well with the values calculated from (a) optical data and (b) ab initio data. The experimental determinations are still much better than theoretical calculations.     

A test of factorisation predictions for the fragmentation processes pp→π± at p momenta of 9.1 and 4.6 GeV/c

Relations have been derived between the invariant cross sections for various inclusive processes by assuming factorisation of the leading (pomeron) and non-leading (meson) trajectories. In this paper predictions for the invariant cross sections $\text{f(}\text{p}\text{p}\text{→π}{}^{\mathrm{\pm }}\text{)(2E}{}^1\text{/π√s)}\text{d}{}^2\text{σ/}\text{d}\text{x}\text{d}\text{p}{}^2{}_{\mathrm{\perp }}{}^2$ have been tested using data from $\text{p}\text{p}$interactions at 4.6 and 9.1 GeV/c.A large discrepancy between experiment and theory is apparent for the π^? data: in the π⁺ case the discrepancy is less marked but still present.     

New measurements of the n2P12,32 energy levels of Cs(I)

The energies of the $\text{n}{}^2\text{P}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{(7 ≤ n ≤ 13)}$ and $\text{n}{}^2\text{P}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}\text{(7 ≤ n ≤ 27)}$ levels of CsI have been redetermined photographically from high resolution absorption measurements of the principal series lines $\text{6}{}^2\text{S}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{? n}{}^2\text{P}{}_{\mathrm{<mtext>J</mtext>}}$X. The new data disagree significantly [ ≈0.13 cm^-1] with the values given in the NBS-Tables of Moore¹ which are taken from a paper by Kratz.² By means of an extended Ritz-formula, the ionization energy of CsI was found to be 31406.46±0.03 cm^-1, which is, within the limit of uncertainty, in agreement with the data of Kleiman,³ Eriksson et al.,⁴ Bockasten,⁵ and Eriksson and Wenåker.⁶     

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.     

Measurement of coherent pion-photoproduction on the 3He/3H isodoublet

Neutral and charged pion-photo production on ${}^3\text{H}$ and ${}^3\text{He}$ nuclei have been observed in the Δ(1232) resonance region. Resonance averaged cross-sections are presented as functions of momentum transfer.