Microwave spectral study of 2-fluorophenol: cis conformer

The microwave spectra of 2-fluorophenol and its deuterated species have been observed and analyzed in the frequency ranges 12.5–18.0 GHz (KU band) and 21.5–26.0 GHz (K band) in the ground vibrational state at room temperature. For the normal species, the radio frequency-microwave double resonance spectrum has been recorded in the frequency range 30.0–38.0 GHz. Three rotational and five quartic centrifugal distortion constants for the normal species, $\text{A}\text{?}\text{= 3337.86 ± 0.02}$, $\text{B}\text{?}\text{= 2231.92 ± 0.01}$, $\text{C}\text{?}\text{= 1337.52 ± 0.01}$, d_J = (3.5 ± 2.9) × 10^?4, d_JK = (?4.9 ± 1.5) × 10^?3, d_K = (?3.2 ± 1.0) × 10^?3, d_WJ = (?2.0 ± 1.0) × 10^?7, d_WK = (2.6 ± 0.8) × 10^?6 (in MHz), and three rotational constants for the deuterated species, $\text{A}\text{?}\text{= 3324.70 ± 0.03}$, $\text{B}\text{?}\text{= 2177.95 ± 0.03}$, $\text{C}\text{?}\text{= 1315.96 ± 0.03}$ (in MHz), have been obtained. Consideration of the r_s coordinate of the hydroxyl hydrogen atom leads to the assignment of the spectra to the cis conformer of the molecule. An r₀ structure for the cis conformer has been proposed. The nonbonded OH ? F distance is lower by about 0.3 Å than the sum of the van der Waals radii.     

Results on the production cross sections π−p → neutrals and π− p→ χ↳2γ0n at 3.8, 6, 8 and 12 GeV/c

The ratio between the cross sections for the reactions $\text{π}{}^{\mathrm{?}}\text{p→}\text{χ}\text{?}{}_{\mathrm{2\gamma }}{}^0\text{n}$ and π^?p → η_→2γ n has been measured to be (2.4 ± 0.9) × 10^?2, (2.1 ± 0.6) × 10^?2 and (2.8 ± 1.3) × 10^?2 at 3.8,6,8 and 12 GeV/c incident momentum respectively.At the same momenta the cross section for π^t- p → neutrals is (1.48 ± 0.09) mb, (0.86 ± 0.05) mb, (0.64 ± 0.04) mb and (0.42±0.03) mb.     

Measurement of the decay-probability of metastable hydrogen by two-photon emission

The two-photon-decay probability of the metastable 2² S_{$\text{1}\text{2}$} level of hydrogen has been measured. The result A(λ)dλ = 1.5 sec^?1 ± 43% in the spectral range dλ = (255.4?232)nm ± 5% is in agreement with the theoretical prediction.     

Large angle production of stable particles heavier than the proton and a search for quarks at the CERN intersecting storage rings

Measurements have been performed on production of particles with mass 1.5 GeV/c² and charge $\text{?}\text{2}\text{3}$ for θ_lab = 62.5° and $\text{s}\text{= 53}\text{GeV}$. At p_T = 0.7 GeV/c the relative rate of production of antideuterons to π^? is (5 ± 1) × 10^?5. The deuteron to antideuteron ratio is 3.7 ± 1.2. No new stable particle has been amongst 0.7 × 10⁸ charged particles entering our detector.     

Isospin dependence of the nuclear level density

Experiments on $\text{(ft)}{}^{\mathrm{+}}\text{/(}\text{ft)}{}^{\mathrm{?}}$ for mirror Gamow-Teller β-decay are reanalyzed in the light of recent work and new values for the Kubodera, Delorme and Rho second class parameters are deduced: ξ = ? (0.8 ± 2.0) × 10^?3MeV^?1; λ = (3.4 ± 3.9) × 10^?3. These values are compared with recent correlation experiments.     

New evaluation of muon (g − 2) hadronic anomaly

The hadronic part a_H of the muon g-factor anomaly $\text{a ≡}\text{(g ? 2)}\text{2}$ is evaluated from latest data on σ(e⁺e^? → hadrons). For a p-wave ππ scattering length of a₁ = 0.04±0.005 we calculate a_H = (66±10) × 10^?9, compared to a(experiment) ? a(QED) = (60±29) × 10^?9. Half of the uncertainty on a_H is associated with the energy interval $\text{0.92 <}\text{s}\text{< 2}\text{GeV}$.     

Experimental detection and investigation of muon catalyzed fusion of deuterium and tritium

Measurement of the neutron yield of the reaction $\text{dt}\text{μ →}{}^4\text{He}\text{+ μ}{}^{\mathrm{?}}\text{+ 17.6}\text{MeV}$, induced by negative muons in a mixture of gaseous D₂ and T₂, has shown that the rate of muon transfer from deuterium to tritium is λ_dt = (2.7 ± 0.9) × 10⁸s^?1 and that the lower limit of the formation rate of dt_μ molecules is λ_dtμ > 10⁸s^?1.     

Determination of A0 for CH335Cl and CH337Cl from the ν4 infrared and Raman bands

The ν₄ infrared and Raman bands of CH₃Cl were analyzed simultaneously. A direct fit yielded a complete set of constants for CH₃³⁵Cl, including A₀ = 5.20530 ± 0.00010 cm^?1 and D_K = (8.85 ± 0.13) × 10^?5cm^?1. For CH₃³⁷Cl an incomplete set of constants was obtained from the infrared band, and A₀ = 5.2182 ± 0.0010 cm^?1 was estimated by curve fitting of the Raman spectrum. The resulting equilibrium structure is $\text{r(}\text{CH) = 1.0854 ± 0.0005}\text{A}\text{?}$, $\text{r(}\text{CCl) = 1.7760 ± 0.0003}\text{A}\text{?}$, and <(HCH) = 110°.35 ± 0°.05.     

Infrared diode laser spectroscopy of the PO radical

Vibration-rotation transitions of the PO radical in the X²Π_r state have been observed by a tunable infrared diode laser spectrometer. The analysis of the observed spectra gave the molecular constants in the v = 1 state and the band origin to be B = 0.7250107(36), D = 1.0253(60) × 10^?4, A_J = 0.997(24) × 10^?4, p = 0.006323(33), A₁ - A₀ = 0.16354(78), and ν₀ = 1220.24901(43), all in cm^?1 units with three standard errors in parentheses, where the v = 0 parameters were fixed to the values previously reported. The equilibrium internuclear distance was determined to be $\text{r}{}_{\mathrm{<mtext>e</mtext>}}\text{= 1.476370(15)}\text{A}\text{?}$.     

Nuclear structure effect in internal conversion of the isomeric transition in 191Os

Measurements have been performed on relative conversion line intensities of the hindered 74.38 keV isomeric transition in ¹⁹¹Os with the $\text{1}\text{2}\text{π√13}$ iron-free β-ray spectrometer. Anomalies were observed for the L, M and N subshell intensity ratios and were explained with a nuclear structure parameter λ = 9.4 ± 0.5 and a mixing ratio $\text{¦δ(}\text{E4/M3}\text{)¦ = (3.0 ± 0.3) × 10}{}^{\mathrm{?3}}$.     

The effect of a magnetic field on the heat conductivity of oxygen and oxygen - argon gas mixtures

The effects of a magnetic field on the heat conductivity of the paramagnetic O₂ and O₂-Ar gas mixtures of different compositions have been studied by using the hot-wire method. The magnetic field has been applied perpendicular to the temperature gradient so that the fractional change ($\text{Δλ}{}^{\mathrm{\perp }}\text{λ}$) of the longitudinal coefficient of thermal conductivity has been measured. For pure O₂, after applying proper corrections the experimental data obtained by using the hot-wire method agreed well with those obtained by using other methods. The experimental ($\text{Δλ}{}^{\mathrm{\perp }}\text{λ}$) data have been interpreted by applying the theory of Knaap and Beenakker and treating O₂ as a mixture of m_s = 0 and m_s = ± 1 states.For O₂-Ar mixtures, the theory of Köhler and Raum has been used and O₂ has been treated as a mixture of m_s = 0 and m_s = ±1 states. By using this approximation, the experimental ($\text{Δλ}{}^{\mathrm{\perp }}\text{λ}$) data have been interpreted fairly well and reasonable values of several cross sections have been obtained.     

Some physical properties of Ternary germanium bismuth telluride (GeBi4Te7) semiconducting crystals

High purity crystals of GeBi₄Te₇ have been prepared, and values of the electrical conductivity, thermoelectric power, Hall constant and of the i.r. reflectivity in the plasma oscillation region have been obtained. To interpret the results a simple three-valley model of the constant energy surfaces is proposed. Values of the dielectric constant (?_g = 35), high frequency index of refraction (n_λ→0 = 5.9), the character of scattering of the free carriers, the Fermi level (E_F = 0.16eV), the mean relaxation time of the free carriers (〈τ〉) = 5.79 × 10^?15sec), the free electron concentration (N = 1.63 × 10²⁰cm^?3), the conductivity effective mass $\text{(m}{}^1{}_{\mathrm{c}}\text{= 0.27)}$ and m₁ = m₃ = 0.51 m₃, m₂ = 0.18 m₀ have been calculated.     

Search for long-lived particles in 200 GeV/c proton-nucleon collisions

A search for long-lived particles (τ ? 10^?8 sec), with changes $\text{±}\text{2}\text{3}\text{, ± 1, ±}\text{4}\text{3}\text{and}\text{± 2}$, produced in 200 GeV pN collisions was performed at the CERN-SPS in a secondary beam equipped with superconducting r.f. separators. Upper limits were obtained for the production of long-lived hadrons and leptons. For charge - 1 particles the limits are at the level of 10^?7 of the pions at a mass m = 0.2 GeV and reach the 10^?11 level from $\text{3}\text{to}\text{8}\text{GeV}$. The production of light antinuclei was measured. The cross sections for ³He production are (1.3 ± 0.3) and (1.9 ± 0.3) × 10^?34 cm²/sr · GeV/c at 21 and 47.4 GeV/c respectively; for t the cross section is (7.6 ± 0.9) × 10^?34 cm²/sr · GeV/c at 23.7 GeV/c.     

Energy of a muonic X-ray transition measured with a crystal spectrometer

The wavelength of the $\text{3}\text{d}{}_{\mathrm{<mtext>5</mtext><mtext>2</mtext>}}\text{?2}\text{p}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}$ muonic X-ray transition in ²⁸Si has been measured relative to the wavelength of the 84 keV gamma ray from a ¹⁷⁰Tm source. The result is λ^Si/λ^Tm = 1.099675 (39). Using the reported value for λ^Tm we find (λ_exp^Si-λ_th^Si)/λ_th^Si = (?9±35) × 10^?6.     

Hyperfine and nuclear quadrupole interactions in copper-doped cadmium oxalate trihydrate single crystals

Electron spin resonance experiments on Cu²⁺ doped in a single crystal of cadmium oxalate trihydrate grown by a slow diffusion technique have been carried out at 77 K. The major features of the ESR spectra can be attributed to divalent copper (3d⁹) in substitutional Cd²⁺ sites. Information has been gained about the hyperfine and quadrupole interactions concerning the ion. The spin-Hamiltonian parameters in the $\text{S =}\text{1}\text{2}$, $\text{I =}\text{3}\text{2}$ manifold are: g_x = 2.0211; g_y = 2.2249; g_z = 2.4536; A_x = +84.5 × 10^?4cm^?1; A_y = +16.8 × 10^?4cm^?1; $\text{A}{}_{\mathrm{z}}\text{= ?40.8 × 10 ×}{}^{\mathrm{?4}}\text{cm}{}^{\mathrm{?1}}$; P_x = ?7.4 × 10^?4cm^?1; P_y = ?0.4 × 10^?4cm^?1; and P_z = +7.8 × 10^?4cm^?1. An evaluation of the asymmetry and quadrupole coupling parameters revealed that the ground state of the guest ion in Cd(COO)₂ · 3H₂O is 0.97|x² ?y₂ > +0.24 |3z² ? r² >.     

Centrifugal distortion effects in the hyperfine spectrum of KCl

The hyperfine spectrum of KCl has been examined at near-zero electric field and zero magnetic field using a molecular beam electric resonance spectrometer. Rotational as well as vibrational shifts have been observed in both nuclear quadrupole interactions. With $\text{eqQ = Q}{}_{00}\text{+ Q}{}_{10}\text{(v +}\text{1}\text{2}\text{) + Q}{}_{20}\text{(v +}\text{1}\text{2}\text{)}{}^2\text{+ Q}{}_{01}\text{J(J + 1)}$, we find (all in units of kHz) for K in ³⁹K³⁵Cl: Q₀₀ = ?5691.47 ± 0.04, Q₁₀ = 51.32 ± 0.06, Q₂₀ = ?0.205 ± 0.020, Q₀₁ = 0.014 ± 0.007, Q₀₀(K³⁷Cl) ? Q₀₀(K³⁵Cl) = ?0.03 ± 0.07; for Cl in ³⁹K³⁵Cl: Q₀₀ = 137.0 ± 0.3, Q₁₀ = ?163.2 ± 0.5, Q₂₀ = 1.57 ± 0.15, Q₀₁ = 0.07 ± 0.03, $\text{[}\text{Q(}{}^{35}\text{Cl}\text{)}\text{Q(}{}^{37}\text{Cl}\text{)}\text{]Q}{}_{00}\text{(}\text{K}{}^{37}\text{Cl}\text{) ? Q}{}_{00}\text{(}\text{K}{}^{35}\text{Cl}\text{) = ?0.5 ± 0.6}$; and magnetic constants c_K = 0.154 ± 0.007, c_Cl = 0.435 ± 0.010, c₃ = 0.035 ± 0.012, and c₄ = 0.009 ± 0.006. These have been used to provide a mapping of the field gradients at both nuclear sites to fourth order in $\text{ξ =}\text{(r ? r}{}_{\mathrm{e}}\text{)}\text{r}{}_{\mathrm{e}}$. We find eQq_K(ξ) = (?5692.5 ± 2.5) + (1.7 ± 0.8) × 10⁴ξ + (?2. ± 4.) × 10⁴ξ² + (?8. ± 18.) × 10⁵ξ³ + (8. ± 15.) × 10⁶ξ⁴ and eQq_Cl(ξ) = (120. ± 22.) + (8. ± 4.) × 10⁴ξ + (?5.8 ± 2.0) × 10⁵ξ² + (?1.1 ± 1.6) × 10⁷ξ³ + (1.1 ± 1.3) × 10⁸ξ⁴.     

Mössbauer spectroscopy study of iodine and tellurium atoms in solid argon

Mössbauer effect studies were performed on the nucleogenic ¹²⁵Te and ¹²⁹I monomers formed by the decay of their respective parents ^125mTe and ^129mTe embedded in solid argon at 4.2 K. Rare-gasmatrix-isolation (RGMI) and ion implantation techniques were combined to produce those extremely diluted Mössbauer emitters. The ¹²⁵Te spectrum is composed of a quadrupole split component with splitting $\text{e}{}^2\text{qQ}\text{2}\text{= 9.2(4)}\text{mm}\text{s}$ and isomer shift $\text{IS = + 0.35(5)}\text{mm}\text{s}$, and a single line component with $\text{IS = +0.15(5)}\text{mm}\text{s}$ with respect to a ZnTe absorber. They are attributed to Te⁰ and Te^?1 species, respectively. The ¹²⁹I spectrum is composed of a single quadrupole split component with $\text{e}{}^2\text{qQ = ?685(20) MHz and IS = +0.75(4)}\text{mm}\text{s}$ with respect to a ZnTe source. This species is attributed to I⁰. Two novel single-line absorbers with high f values at RT were developed for the Te and I experiments, e.g. Mg₃TeO₆ and Na₅IO₆. Based on our results for Te⁰ and Te^?1 and on relativistic Dirac-Slater atomic calculations, a new IS calibration curve under the form of a nonlinear relationship of IS versus the number of p holes (h_p) in the closed shell configuration of 5s²5p⁶ is established for ¹²⁵Te. The IS data of the I⁰ monomer are used to refine the IS(h_p) relationship for ¹²⁹I. From these new calibration curves values are deduced for the change in mean-squared charge radius Δ〈r²〉 = 3.4(3) 10^?3fm² for ${}^{125}\text{Te and Δ〈r}{}^2\text{〉 = 19.9(7) 10}{}^{\mathrm{?3}}\text{fm}{}^2$ for ¹²⁹I, respectively. The origin of the quadrupole interaction and the experimental features of this RGMI-implantation-Mössbauer emission spectroscopy are fully discussed.     

Non-perturbative QCD effects explain the ΔI = 12 rule in the chiral limit

It is shown that in the chiral limit, the enhancement of the $\text{ΔI=}\text{1}\text{2}$ transitions for mesons is explained by the large size of non-perturbative QCD matrix elements. For $\text{〈}\text{s}\text{s〉 = 〈}\text{u}\text{u〉}$ we obtain ∣M(K_S⁰ → 2π⁰) ∣ =(5.2±0.6) × 10^?7m_K in excellent agreement with experiment.     

The average structure of 5.10-Dihydro-5.10-Diethylphenazinium-Iodide (E2P·I1.6): A new linear chain Polyiodide compound

Upon oxidation of 5.10-dihydro-5.10-diethylphenazine (E₂P) with iodine golden-green lustrous crystals of a compound with stoichiometry E₂P.I_1.6 were isolated. The compound crystallizes in the tetragonal space group D₄² with $\text{a = 12.321(2)}\text{A}\text{?}$ and $\text{c = 5.330(2)}\text{A}\text{?}$. The E₂P and I form interpenetrating incommensurate sublattices along c, with an iodine repeat distance of 9.7 Å. Static susceptibility measurements at room temperature give χ_g = + 0.994 × 10^?6g^?1 × cm³. This corresponds to one unpaired electron spin per two formular units. Single-crystal EPR indicates that the paramagnetism is associated with weakly interacting E₂P⁺ cation radicals. The 300K-d.c. conductivity of 3×10^?2Ω^?1cm^?1 and activation energy of 0.17±0.02eV for single crystals is consequently associated with the polyiodide chains, and not with the E₂P⁺ cation radicals.     

Observation of the radiative transition ψ → γE(1420)

We have observed a radiative transition from the ψ to a state decaying into K_SK^±π^?, with mass M = 1.44_?0.015^+0.01 GeV/c² and width Γ = 0.05_?0.02^+0.03 GeV/c². We tentatively identify this state as the E(1420). Assuming that this state is an isospin singlet, we have determined the branching fraction product $\text{B(ψ → γ}\text{E}\text{) × B(}\text{E}\text{×}\text{K}\text{K}\text{π) = (3.6 ± 1.4) × 10}{}^{\mathrm{?3}}$.