Measurement of the isospin amplitude ∣M012∣ in the reaction γn → ϱ0(pπ−) at 7.5 GeV

The cross-channel isospin amplitude $\text{∣M}{}_0{}^{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{∣}$ is measured in the single reaction γn → ?⁰(pπ^?) at 7.5 GeV assuming the ?⁰ dominance model. A low-mass enhancement is found for $\text{∣M}{}_0{}^{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{∣}{}^2$ in the range of m(pπ^?) of ～1.2 to ～1.7 GeV. The reaction strongly violates s-channel helicity conservation but is consistent with t-channel helicity conservation. The $\text{∣M}{}_0{}^{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{∣}$ features are found to be very similar to those obtained in previous analyses of πp → π(Nπ) reactions.     

Evidence for a narrow peak in Ksoπ±π+π- at 2.6 gev in 12 gev/cpp interactions

We report the evidence for a narrow charged peak (5.5 s.d.), which we suggest calling the I, in the 6-prong-V⁰ topology of $\text{p}$p interactions at 12 GeV/c. The mass, widht and the product of cross section σ_I times the branching ratio BR into the final state (K_s^oτ±τ⁺τ^? are found to be: $\text{M}{}_{\mathrm{I}}\text{=2.60 ±}\text{0.01}\text{GeV}\text{/}\text{c}{}^2$, $\text{Γ}{}_{\mathrm{I}}\text{?}\text{0.018}\text{GeV}\text{/}\text{c}{}^2$, σ_I·BR≈20 μbarn     

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.     

Lifetime of electronic states of CO2+

The radiative lifetimes of the $\text{A}\text{?}{}^2\text{Π}{}_{\mathrm{u}}$ and $\text{B}\text{?}{}^2\text{Σ}{}_{\mathrm{u}}{}^{\mathrm{+}}$ states of CO₂⁺ were measured by means of the delayed coincidence method. Excitation was performed by a pulsed electron beam incident on CO₂. The results of these measurements are 115 ± 5 nsec for the $\text{A}\text{?}{}^2\text{Π}{}_{\mathrm{u}}$ state and 126 ± 3 nsec for the $\text{B}\text{?}{}^2\text{Σ}{}_{\mathrm{u}}{}^{\mathrm{+}}$ state.     

Analysis of the I = 0 s-wave for ππ and KK̄ scattering

We show that if one uses a coupled channel parametrisation for the I = 0 S-wave in processes $\text{ππ → ππ, ππ →}\text{K}\text{K}\text{?}$ and KK? → KK? (the last deduced from a $\text{p}\text{?}\text{p → ππ + K}{}_1{}^0\text{K}{}_1{}^0\text{experiment}$) taking properly into account the analytic structure of these waves, then it is possible to fit simultaneously all cross-sections for the above processes, in the ranges $\text{700 < s s}{}^{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{< 1900}\text{MeV}$ for the first fit, $\text{2M}{}_{\mathrm{<mtext>K</mtext>}}\text{< s}{}^{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{< 1500}\text{MeV}$ for the second, $\text{2M}{}_{\mathrm{<mtext>K</mtext>}}\text{< s}{}^{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{< 1170}\text{Mev}$ for the last. None of the three usually claimed resonances ?, S¹, ?′ show up in the corresponding eigenphase analysis.     

The dipole moment of thioformaldehyde in its singlet and triplet π1 − n excited states

Laser-induced fluorescence excitation has been used to measure Stark splittings of selected lines in the $\text{A}\text{?}{}^1\text{A}{}_2\text{-}\text{X}\text{?}{}^1\text{A}{}_1$ and $\text{a}\text{?}{}^3\text{A}{}_2\text{-}\text{X}\text{?}{}^1\text{A}{}_2$ band systems of H₂CS in electric fields up to 13 kV/cm. The derived excited state a-axis dipole moments are 0.820 ± 0.007 D for the 4¹ level of the ¹A₂ state; 0.838 ± 0.008 D for the zeroth vibrational level of ¹A₂; and 0.534 ± 0.015 D for the zeroth vibrational level of the ³A₂ state. These results are compared with the corresponding values of H₂CO, and interpreted in terms of the changing localization of the π and $\text{π}{}^1$ orbitals accompanying electronic excitation.     

Study of the photon spectrum in the decay KS0→π+π−γ

The branching ratio $\text{Λ(}\text{K}{}_{\mathrm{<mtext>S</mtext>}}{}^0\text{→π}{}^{\mathrm{+}}\text{π}{}^{\mathrm{?}}\text{γ)}\text{Λ(}\text{K}{}_{\mathrm{<mtext>S</mtext>}}{}^0\text{→π}{}^{\mathrm{+}}\text{π}{}^{\mathrm{?}}\text{)}$ has been determined to be (2.68±0.15)×10^?3 for photon energies $\text{E}{}_{\mathrm{\gamma }}{}^1$ greater than 50 MeV in the K_S⁰ rest frame. The decay K_S⁰→π⁺π^?γ is found to be dominated by the internal bremsstrahlung transition. The branching rato of a possible direct transition is found to be less than 0.06 × 10^?3 at 90% confidence level for $\text{E}{}_{\mathrm{\gamma }}{}^1\text{> 50}\text{MeV}$.     

Magnetic moment of the 72+[404] ground state of 10.5 h 175Ta

The magnetic hyperfine splitting ν_M = |gμ_NB_HF/h| of ${}^{175}\text{Ta}\text{(J}{}^{\mathrm{\pi }}\text{=}\text{7}\text{2}{}^{\mathrm{+}}$; $\text{T}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{= 10.5}\text{h}\text{)}$ in Fe has been measured with the technique of nuclear magnetic resonance on oriented nuclei as 320.4(1) MHz. With the known hyperfine field $\text{B}{}_{\mathrm{<mtext>HF</mtext>}}\text{(}\text{Ta}\text{Fe}\text{) = ?648(13)}\text{kG}$ the magnetic moment of the $\text{7}\text{2}{}^{\mathrm{+}}\text{[404]}$ ground state of ¹⁷⁵Ta is deduced to be $\text{¦μ¦ = 2.27(5)μ}{}_{\mathrm{<mtext>N</mtext>}}$.     

Laser magnetic resonance spectrum of BrO (2Π12 ← 2Π32)

Magnetic dipole transitions between the ${}^2\text{Π}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ and ${}^2\text{Π}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}$ components of the ground electronic state of BrO have been detected using the technique of laser magnetic resonance on three CO₂ laser lines between 964 and 970 cm^?1. This is the first direct observation of the ${}^2\text{Π}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ state in BrO. The spin-orbit splitting parameter, A, is determined to be ?967.9831(2) cm^?1 for ⁷⁹Br¹⁶O and ?967.9981(2) cm^?1 for ⁸¹Br¹⁶O. Accurate values for the rotational constant $\text{B}{}^{\mathrm{<mtext>eff</mtext>}}\text{(}{}^2\text{Π}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{)}$, the hyperfine parameters ($\text{b}{}_{\mathrm{F}}\text{+}\text{2c}\text{3}$) and d, the Λ-doubling parameter p, and the Zeeman parameter g| are also determined from an analysis of the measured spectra.     

Silver-compensated germanium center in α-quartz

A synthetic germanium-doped crystal of α-quartz was subjected to an electro-diffusion process $\text{ca. 600}\text{V}\text{cm}$, 625°K), in which Ag⁺ ions were introduced along the crystal's optic axis (c). A 9800MHz electron paramagnetic resonance spectrum at room temperature, taken after room temperature x-irradiation, revealed the presence of a silver-compensated germanium center A_Ge?Ag with large, almost isotropic ¹⁰⁷Ag and ¹⁰⁹Ag hyperfine splittings (26.078, 30.112 mT for magnetic field B∥c). Measurement of the spin-Hamiltonian (i.e. matrices $\text{g}$, $\text{A}{}^{73}{}_{\mathrm{<mtext>Ge</mtext>}}$, $\text{A}{}^{107}{}_{\mathrm{<mtext>Ag</mtext>}}$ and $\text{A}{}^{109}{}_{\mathrm{<mtext>Ag</mtext>}}\text{)}$ discloses that a suitable model for the observed center utilizes germanium, substituted for silicon, with the accompanying silver interstitial in a nearby c-axis channel, and with electronic structure in which an appreciable admixture Ge⁴⁺?Ag⁰ to Ge³⁺?Ag⁺ exists. Estimates of the unpaired electron orbital are presented.     

Determination of the spectroscopic quadrupole moments of 131Cs, 132Cs and 136Cs

Nuclear spectroscopic quadrupole moments of the radioactive isotopes ¹³¹Cs, ¹³²Cs, and ¹³⁶Cs have been determined from the hyperfine structure of the $\text{6}{}^2\text{P}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}$ state by the level crossing method. The results including a Sternheimer correction are: $\text{Q}{}_{\mathrm{<mtext>s</mtext>}}\text{(}{}^{131}\text{Cs}\text{) = ?0.625(6)}\text{b}$, $\text{Q}{}_{\mathrm{<mtext>s</mtext>}}\text{(}{}^{132}\text{Cs}\text{) = +0.508(7)}\text{b}$, $\text{Q}{}_{\mathrm{<mtext>s</mtext>}}\text{(}{}^{136}\text{Cs}\text{) = +0.225(10)}\text{b}$. The quadrupole moments of all the Cs isotopes from A = 131 to A = 137 are recalculated. It is shown, that nuclear quadrupole moments of a specific isotope obtained from different atomic P-states only agree within the limits of error after application of the Sternheimer correction. The increase of Q_s with decreasing neutron number conforms with other observations and theoretical calculations stating that for elements around Z = 55 nuclear deformation develops below N = 82. The staggering of the sign of Q_s may be interpreted as consequence of an oblate-prolate degeneracy of the nuclear energy surface. Some magnetic moments have been slightly improved: $\text{μ}{}_{\mathrm{<mtext>I</mtext>}}\text{(}{}^{132}\text{Cs}\text{) = 2.219(7) μ}{}_{\mathrm{<mtext>N</mtext>}}$, $\text{μ}{}_{\mathrm{<mtext>I</mtext>}}\text{(}{}^{136}\text{Cs}\text{) = 3.705(15)μ}{}_{\mathrm{<mtext>N</mtext>}}$ (corrected for diamagnetism).     

Chemical diffusion in nonstoichiometric chromium sulfide,Cr2+yS3

Using the re-equilibration kinetic method the chemical diffusion coefficient in nonstoichiometric chromium sesquisulfide, Cr_2+yS₃, has been determined as a function of temperature (1073–1373 K) and sulphur vapour pressure (10?10⁴ Pa). It has been found that this coefficient is independent of sulphur pressure and can be described by the following empirical equation: $\text{D}\text{?}\text{Cr}{}_{\mathrm{2+y}}\text{S}{}_3\text{=50.86}\text{exp(-39070 cal/mole/}\text{RT)}\text{(cm}{}^2\text{s}{}^{\mathrm{?1)}}$. It has been shown that the mobility of the point defects inCr_2+yS₃ is independent of their concentration and that the self-diffusion coefficient of chromium in this sulfide has the following function of temperature and sulphur pressure: . (cm²s^?1).     

Nuclear magnetic moment of the 9.7 h 12− isomer 196mAu

The magnetic hyperfine splitting v_M=|gμ_NB_HF/h| of ^196mAu (j^π=12^?; configuration ¦(π$\text{11}\text{2}$($\text{v}\text{13}\text{2}{}^{\mathrm{+}}\text{)〉}{}_{12}{}^{\mathrm{?}}$; $\text{T}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{= 9.7}\text{h}\text{)}$ as dilute impurity in Ni has been determined with nuclear magnetic resonance on oriented nuclei as 96.0(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 ^196mAu are deduced to be |g| = 0.476(7) and |μ| = 5.72(8) μ_N. Taking into account the known magnetic properties of $\text{π}\text{1}\text{2}{}^{\mathrm{?}}$ and $\text{v}\text{13}\text{2}{}^{\mathrm{+}}$ isomeric states in the neighbouring odd Pt, Au and Hg nuclei the structure of the 12^? state is discussed.     

Evidence for the stratification of epitaxial films of Y2.85La0.15Fe3.75Ga1.25O12 from microwave resonance measurements

Ferromagnetic resonance experiments on thin epitaxial films of Y_2.85La_0.15Fe_3.75Ga_1.25O₁₂, grown by a vertical dipping technique, provide strong evidence for stratification of these films. Perpendicular resonance spectra recorded after etching off the magnetic film step by step show resonances due to six strata in 4 μm thick films. Of each stratum the thickness has been determined as well as the magnetic anisotropy. It is found that the layer next to the interface is 0.4 μm thick and has a strongly negative $\text{K}{}_{\mathrm{u}}\text{(}\text{K}{}_{\mathrm{u}}\text{M}\text{= -400}\text{Oe}\text{)}$. Strata remote from the substrate are 1 μm thick and have a positive $\text{K}{}_{\mathrm{u}}\text{(}\text{K}{}_{\mathrm{u}}\text{M}\text{≈ + 150}\text{Oe}\text{)}$.     

The QCD effective coupling constant in e+e− annihilation

The QCD effective coupling constant α_s(Q²) is determined by comparing the O(α_s)² jet-distributions with the high-energy e⁺e^? data from PETRA. We get α_s(Q² = 1225 GeV²) = 0.125 ± 0.01, which corresponds to $\text{Λ}{}_{\mathrm{<mtext>MS</mtext>}}\text{= 110}{}^{\mathrm{+70}}{}_{\mathrm{?50}}\text{MeV}$ with five flavours.     

Measurement and interpretation of the 1-0 band of 14N16O at 1900 cm−1

The wavenumbers of the vibration rotation band lines of ¹⁴N¹⁶O are reported for the ${}^2\text{Π}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{-}{}^2\text{Π}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$, ${}^2\text{Π}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{-}{}^2\text{Π}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ and ${}^2\text{Π}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{-}{}^2\text{Π}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ subbands of the 1-0 transition in the infrared. The full set of spectroscopic constants for this band has been determined by direct approach using the analysis of Zare, Schmeltekopf, Harrop, and Albritton. In addition to the band origin ν₀ and the B, D, H constants for the lower and upper vibrational levels, the following spin-orbit coupling constants have been derived: $\text{A}\text{?}{}_0\text{= 123.02772 ± 0.00011}$ and $\text{A}\text{?}{}_1\text{= 122.78248 ± 0.00011}$ (in cm^?1). Apparent centrifugal corrections to these constants have been determined and the values obtained for them are $\text{A}\text{?}{}_{\mathrm{<mtext>D</mtext><mtext>0</mtext>}}\text{= (0.347573 ± 0.00051) × 10}{}^{\mathrm{?3}}$ and $\text{A}\text{?}{}_{\mathrm{<mtext>D</mtext><mtext>1</mtext>}}\text{= (0.337135 ± 0.00050) × 10}{}^{\mathrm{?3}}\text{cm}{}^{\mathrm{?1}}$. Λ-Type doubling constants evaluated by using both grating and tunable laser data are also reported.     

Low-lying levels of 140Pr

The doubly odd nucleus ¹⁴⁰Pr has been investigated by means of the ¹⁴¹Pr(d, t)¹⁴⁰Pr and ¹⁴⁰Ce(p, nγ)¹⁴⁰Pr reactions. Twenty-eight levels, up to 1300 keV excitation, were observed in the pickup study. DWBA analysis was used to determine l-values and spectroscopic factors for all but a few which are very weakly populated. Gamma-ray angular distributions, measured at E_p = 4.78 MeV for the five strongest γ-rays, show appreciable nuclear alignment and demonstrate the feasibility of such experiments in this mass region. Taken together, the two studies have permitted the identification of the 12 levels expected from the low-lying ($\text{π2}\text{d}{}_{\mathrm{<mtext>5</mtext><mtext>2</mtext>}}\text{ν2}\text{d}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}{}^{\mathrm{?1}}$), ($\text{π2}\text{d}{}_{\mathrm{<mtext>5</mtext><mtext>2</mtext>}}\text{ν3}\text{s}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}{}^{\mathrm{?1}}$), ($\text{π1}\text{g}{}_{\mathrm{<mtext>7</mtext><mtext>2</mtext>}}\text{ν2}\text{d}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}{}^{\mathrm{?1}}$) and (π1g_{$\text{7}\text{2}$}ν3s_{$\text{1}\text{2}$}^?1) configurations. Tenta assignments for the strong odd-parity states are suggested on the basis of their spectroscopic factors.     

The electronic isotope shift in the A2Π-X2Σ+ bands of BeH,BeD and BeT

The 0-0, 1-1, 2-2, and 3-3 bands of the A²Π-X²Σ⁺ transition of the tritiated beryllium monohydride molecule have been observed at 5000 Å in emission using a beryllium hollow-cathode discharge in a He + T₂ mixture. The rotational analysis of these bands yields the following principal molecular constants.

$\text{A}{}^2\text{Π:}\text{B}{}_{\mathrm{e}}\text{= 4.192}\text{cm}{}^{\mathrm{?1}}\text{; r}{}_{\mathrm{e}}\text{= 1.333}\text{A}\text{?}$

$\text{X}{}^2\text{Σ:}\text{B}{}_{\mathrm{e}}\text{= 4.142}\text{cm}{}^{\mathrm{?1}}\text{; r}{}_{\mathrm{e}}\text{= 1.341}\text{A}\text{?}$

$\text{ω}{}_{\mathrm{e}}\text{′ ? ω}{}_{\mathrm{e}}\text{″ = 16.36}\text{cm}{}^{\mathrm{?1}}\text{; ω}{}_{\mathrm{e}}\text{′X}{}_{\mathrm{e}}\text{′ ? ω}{}_{\mathrm{e}}\text{″X}{}_{\mathrm{e}}\text{″ = 0.84}\text{cm}{}^{\mathrm{?1}}$

From the pure electronic energy difference (E_Π - E_Σ)_BeT = 20 037.91 ± 1.5 cm^?1 and the corresponding previously known values for BeH and BeD, the following electronic isotope shifts are derived

$\text{ΔE}{}_{\mathrm{e}}{}^{\mathrm{i}}\text{(}\text{BeH}\text{?}\text{BeT}\text{) = ?4.7 ≠ 1.5}\text{cm}{}^1\text{, ΔE}{}_{\mathrm{e}}{}^{\mathrm{i}}\text{(}\text{BeH}\text{?}\text{BeT}\text{) = ?1.8 ≠ 1.5}\text{cm}{}^1$

and related to the theoretical approach given by Bunker to the problem of the breakdown of the Born-Oppenheimer approximation.     

The rotational analysis of the 1Π-X 1Σ+ system at 649.5 nanometers of zirconium oxide

A red-degraded band head, normally badly overlapped by the gamma system, $\text{A}{}^3\text{Φ}\text{- X′}{}^3\text{Δ}$, of zirconium oxide, appears in emission spectra of zirconium arcs and in absorption spectra of S-type stars and of frozen rare gas matrices containing zirconium. The emission band has been examined at high-resolution with the aid of separated zirconium isotopes. Identification of the band as 0-0 of a ${}^1\text{Π}\text{- X}{}^1\text{Σ}{}^{\mathrm{+}}$ system of zirconium oxide is confirmed by rotational analysis where the following constants (cm^?1) are obtained for ⁹⁰Zr¹⁶O:

$\text{B}{}_0\text{′(R,P) = 0.40142 D}{}_0\text{′(R,P) = 3.51 × 10}{}^{\mathrm{?7}}$

$\text{B}{}_0\text{′(Q) = 0.40166 D}{}_0\text{′(Q) =3.52 × 10}{}^{\mathrm{?7}}$

$\text{B}{}_0\text{″ = 0.42263 D}{}_0\text{″ =3.19 × 10}{}^{\mathrm{?7}}$

$\text{ν}{}_0\text{= 15383.81s}$

The Λ-type doubling in the ¹Π state and the question of whether $\text{X}{}^1\text{Σ}{}^{\mathrm{+}}$ or $\text{X′}{}^3\text{Δ}$ is the true ground state of ZrO are discussed.