Determination of the radiative widths of the η′ and A2 from two-photon exchange production

From the two-photon exchange processes e⁺e^? → e⁺e^?η' (958) → e⁺e^??⁰γ and e⁺e^? → e⁺e^?A₂ (1310) → e⁺e^?π⁺π^?π⁰ observed using the CELLO detector at PETRA the radiative widths of the η' and A₂ have been determined with the results: Γ_γγ(η') = 5.4 ± 1.0[stat.] ± 0.7[syst.] keV; Γ_γγ(A₂) = 0.59 ± 0.14[stat.] _?0.08^+0.31[syst.] keV.     

The spectra and structure of indium iodide: The rotational and vibrational constants of the B 1 state

The rotational constants of the B 1 state of indium iodide are reported for the first time as B_e = 0.037533 cm⁻¹ and α_e = 0.000289 cm⁻¹ while T_e = 25050.60 cm⁻¹ for the B1-X0⁺ transition. Accurate vibrational constants are also computed from measured Q heads as ω_e= 146.36 cm⁻¹ and ω_eχ_e = 2.20 cm⁻¹.     

On the Determination of the Equilibrium Structure of the PH3 Molecule

Values of the r_e and α_e equilibrium structural parameters of the PH₃ molecule have been determined on the basis of experimental data on the fundamental bands of the PH₂D and PHD₂ species only, without any knowledge of the force-constant-type parameters of the PH₃ molecule. The functions of the equilibrium rotational parameters A^e, B^e, and C^e have been determined. These functions are totally independent of the values of any resonance interaction parameters. Then these functions have been used to determine r_e and α_e constants. The obtained values r_e=(1.416 776±0.000 164) Å and α_e=(93.56±0.29)° differ a little from those found in the earlier literature.     

The temperature dependence of piezoelectric constants eiμ of μ-quartz

Measurements of the temperature dependence of e₁₁ and e₁₄ of α-quartz relative to room temperature based on thichkness mode resonances and antiresonances show that e₁₄ changes its sign at ≈360°C. Fair agreement of e₁₁ with values reported in earlier work was found.     

Observation and analysis of the Xe−I collisional-pair photoassociation spectrum

The interpretation of the photoassociation spectrum arising in collisions of Xe and I atoms is refined with allowance for new data concerning the interaction potential of Xe and I collisional pairs. Spectroscopic constants for the XeI(B) state are determined:R′ _e =3.264961 Å,D′ _e =33,289.05 cm^?1,w′ _e =113.867826 cm^?1, andw′ _e x′ _e =0.238304 cm^?1.     

Multihadronic decays and partial widths of the J/Ψ (3100) resonance produced in e+e− annihilation at adone

The reactions e⁺e^?→ hadrons and e⁺e⁺e^?→e⁺e^? have been studied at the J/gY (3100) resonance). The relative weights of the topological cross sections for fixed charged multiplicity are σ₂=(32±5)%, σ₄=(49±8)%, σ₆=(18±3)%, and σ₈=(1±0.6)%. The average pion multiplicities are 〈n_ch〉=3.8±0.3 and 〈n_{π^o〉=3.1±0.8}. The decay widths are Γ_e=(4.6±0.8) keV, Γ_h=(59±24) keV, and Γ=(68±26) keV.     

An experimental limit on the decayK +→μ+ v e

We have searched for the decay modeK ⁺→μ⁺ v _e by looking for thev _e interactions in a neon/hydrogen bubble chamber. The observed events with electrons are consistent with being produced byv _e from the decaysK ⁺→π⁰ e ⁺ v _e . We set a 90% confidence level upper limit of 0.4% for the μ⁺ v _e decay mode of positive kaons.     

A method for predicting the anharmonicity constants ωeχe of halides of sodium

A method is proposed for estimation of the vibrational anharmonicity constants ω_eχ_e of diatomic molecules. The procedure involves fitting of the potential energy curve obtained by the RKRV method with that obtained by using the 5-parameter Hulburt-Hirschfelder potential function. We have predicted values of ω_eχ_e for alkali halides for which accurate data are not available.     

Gravity modulation study on opposed flame spread over thin solid fuels

In this work a numerical investigation has been carried out to study the effect of g-jitter on zero-gravity (0g_e) opposed flow spreading flame over thin solid fuels. For comparison simulations have also been carried out for normal gravity (1g_e) downward spreading flames. G-jitter is emulated by gravity modulation of sinusoidal (A_ge sin(2πt/T_ge)) gravity perturbation (g-perturbation) of a particular time-period (T_ge) and amplitude (A_ge) over a selected base gravity level (0g_e or 1g_e). The response of flames at 0g_e base gravity and at 1g_e base gravity was different to the imposed g-perturbation. While at 0g_e the mean and the amplitude of the oscillatory flame spread rate (FSR) magnified with increase in the time period of g-perturbation, interestingly for the 1g_e flame a maximum mean FSR and oscillation amplitude occurs at certain perturbation time period. Further, at very small perturbation time-periods (T_ge) the FSR at 1g_e was lower than the steady state FSR. The amplitude of oscillatory FSR increased with increase in perturbation amplitude (A_ge). However, the 0g_e flame which is little affected (compared to 1g_e flame) at small perturbation amplitude (A_ge) is affected severely at large perturbation amplitude (A_ge). Both the gas phase and fuel pyrolysis (or fuel response) follow perturbation signal with a lag but fuel pyrolysis is more sluggish and lags behind gas phase. The phase lag between fuel pyrolysis and gas increases at smaller time-periods (T_ge) and tends to enhance the effect of external perturbation whereas at larger time-periods (T_ge) this lag inhibits the effect of external perturbation.     

The A2Π-X2Σ+ emission spectrum of zinc deuteride

The A²Π-X²Σ⁺ emission of ZnD was studied at moderate and high resolution in the region 346–505 nm. A detailed rotational analysis of 10 bands has been performed using the ²Π formulas of Mulliken and Christy, with the Almy and Horsfall centrifugal distortion term. The principal molecular constants for the X²Σ⁺ state are (cm^?1): B_e = 3.3990, α_e = 0.0964, D_e = 1.16 × 10^?4, β_e = 6.4 × 10^?6, γ₀ = 0.122, ω_e = 1141.54, ω_ex_e = 24.29, and, for the A²Π state, T_e = 23 280.55, B_e = 3.7772, α_e = 0.0868, D_e = 1.14 × 10^?4, A₀ = 343.29, p₀ = 0.149, q₀ = 1.53 × 10^?3, ω_e = 1361.49, and ω_ex_e = 20.69. RKR potential curves and A-X Franck-Condon factors were calculated. A comparison was made with the spectrum of ZnH and the isotopic splitting for ⁶⁴ZnD, ⁶⁶ZnD, and ⁶⁸ZnD is briefly discussed.     

Leptonic polarization asymmetries ate + e − colliders inE 6 theories

We examine the left-right and azimuthal polarization asymmetries of lepton pairs produced ine ⁺ e ^? ande ^? e ^? interactions as probes of new physics resulting fromE ₆ theories. The asymmetries are calculated and compared for the processese ⁺ e ^?→µ ⁺ µ ^?,e ⁺ e ^?→e ⁺ e ^?,e ^? e ^?→e ^? e ^?, ande ⁺ e ^?→L ⁺ L ^? whereL is either anE ₆ exotic, mirror, or fourth generation heavy lepton. Our results show that lepton polarization asymmetries can be used to easily distinguish differentE ₆ models and can be used to distinguish among possible new heavy leptonsL.     

Search for narrow resonances in the reaction γ + Be → e+e− + X at 1.8 ⩽ Me+e− ⩽ 2.6 GeV

The reaction γ + Be → e⁺e^? + X was studied with a bremsstrahlung beam of 7.2 GeV maximum energy. For invariant pair masses 1.8 ? M_e⁺e^? 2.6 GeV, no evidence for narrow resonance of width smaller than 40 MeV was found. For the mass interval 2.1 ? M_e⁺e^? ? 2.6 GeV, we obtained an upper limit of σ · B_e⁺e^? < 2 × 10^?35 cm²/nucleon (90% confidence level), assuming a production mechanism similar to the θ (1019) meson.     

Mirror fermions,universality and the beam dump experiment

The electron deficiency observed in beam dump experiments is discussed within the mirror fermion model. We make a general study of the leptonic weak universality and show that only a 4% change in thee/μ-ratio due to non-universal vector/axial vector charged couplings is allowed. In the mirror fermion model this corresponds to the possibility that the electron-like mirror neutrinoN _e is very heavy. IfN _e is light enough to be produced, oscillation ofv _e into sterileN _e is possible. IfN _e is lighter than about 1 MeV, only a 6.5% decrease in thee/μ ratio is allowed, due to the constraints from reactor neutrino experiments. However, if \(m_{N_e } \) is between a couple of MeV's and 45 MeV, only one loose bound exists, allowing thee/μ ratio to decrease by 11%.     

Spin-orbit effects in the ground X2Π state and two low-lying excited valence states B2Π and L′2Φ for NO

The potential energy curves and spectroscopic constants B _e , ω _e , ω _e χ _e , α _e , D _e of the six Ω states (X ²Π_1/2, ? 3/2, B ²Π_1/2, ? 3/2 and L ^′2Φ_{5/2,   7/2}) of the NO radical molecule were calculated using spin-orbit multi-configuration quasi-degenerate perturbation theory (SO-MCQDPT). The spin-orbit coupling effect was considered via the state interaction approach with the full Breit-Pauli Hamiltonian. The spin-orbit splitting energy between the X ²Π_1/2 and X ²Π_3/2 states of the NO radical is 129.61 cm^-1, which agrees reasonably well with the experimental value of 123.13 cm^-1. For the B ²Π_{1/2,   3/2} states, the spin-orbit coupling (SOC) splitting energy is 35.99 cm^-1, the corresponding experimental value is 31.7 cm^-1. The SOC splitting value of the L ^′2Φ_{5/2,   7/2} states was calculated to be 103.2 cm^-1. The spectroscopic constants R _e , ω _e , ω _e χ _e , B _e , α _e , D _e are in reasonable agreement with available experimental and theoretical data for the six Ω states.     

“Artificial vacuum” for T-violation experiment

We point out the possible use of matrix isolation spectroscopy in experimental tests of fundamental physics. As a concrete example we show how this technique might be applied to measuring the T-violation electron electric dipole moment d_e. We estimate that a dipole moment could be detected down to d_e ∼ 6 × 10⁻²⁸e cm, in comparison to the current limit of d_e < 10⁻²⁴e cm.     

Multiplicity distributions in e+e− annihilations at petra energies

Measurements of the charged multiplicities for hadron production in e⁺e^? annihilation in the center of mass energy range 9–32 GeV have been made. The average charged multiplicity has an energy dependence much stronger than ln s and similar to that reported for pp collisions. Quantitative differences are observed in the magnitude of both the average multiplicity 〈n_ch〉 and the dispersion D_ch for e⁺e^? and pp interactions at the same center of mass energy. 〈n_ch〉 and the ratio 〈n_ch/D_ch in e⁺e^? annihilations are significantly larger than in pp collisions and are found to be in overall agreement with QCD predictions. KNO scaling is seen to be satisfied.     

Hot-wire measurements of the electron thermal conductivity in a potassium plasma

The electron thermal conductivity λ_e of a potassium plasma is found by measuring the electron heat flux in a hot-wire device placed in a magnetic field. In the range 2300–3000 K, λ_e (W/mK) = 0.906 X 10¹⁰ T^-2_e exp(-3.2 X 10⁴/T_e) at a plasma pressure of 800 Pa and a gas temperature T_a = T_e/1.3.     

Effects on spectroscopic properties for several low-lying electronic states of CS molecule by core-valence correlation and relativistic corrections

The potential energy curves (PECs) of six low-lying electronic states (X¹Σ⁺, a³Π, a′³Σ⁺, d³Δ, e³Σ⁻ and A¹Π) of CS molecule have been investigated using the full valence complete active space self-consistent field (CASSCF) method followed by the highly accurate valence internally contracted multireference configuration interaction (MRCI) approach with large correlation-consistent basis sets. Effects on the PECs by the core-valence correlation and relativistic corrections have been taken into account. And the two corrections are performed at the level of cc-pV5Z basis set. The way to consider the relativistic corrections is to use the second-order Douglas-Kroll Hamiltonian approximation. Using the CCSD(T), MRCI and MRCI with the Davidson modification (MRCI + Q), the PECs of electronic states involved are extrapolated to the complete basis set (CBS) limit. With the PECs, the spectroscopic parameters (T_e, R_e, ω_e, ω_ex_e, ω_ey_e, α_e, β_e, γ_e and B_e) of the six low-lying electronic states are determined. These parameters are in excellent agreement with the experimental data. The complete vibrational states are computed for the six low-lying electronic states when the rotational quantum number J equals zero, and the inertial rotation constants of the first 23 vibrational states are reported, which agree favorably with the RKR data. Comparison with the measurements shows that the two-point total-energy extrapolation scheme can obviously improve the quality of spectroscopic parameters and molecular constants.     

Laser magnetic resonance for the v = 1 ← 0 transition of SeO (X3Σ−) by a CO2 laser

The vibration-rotation transitions for a fundamental band of SeO (X³Σ^?) were studied by means of the infrared laser magnetic resonance (LMR) method employing a CO₂ laser. The LMR spectra arising from five SeO isotopic species except ⁷⁴SeO were detected and analyzed. Band origins for these species were determined. Molecular parameters ω_e, ω_eχ_e, B_e, and α_e, were obtained with the aid of the reduced mass relations. For ⁷⁷SeO the axial component of magnetic hyperfine interaction was obtained.     

Systematics of diatomic molecular transition moments: Encouraging progress—II

Literature absolute transition moments for A-X(0-0) bands have been compiled and used to obtain “best” values of R_e for some 90 transitions. Correlations were sought between R_e and various molecular parameters such as multiplicity, average internuclear separation, etc. None was found. The A-X (and related) R_e have been plotted for isoelectronic molecules against the nuclear charge difference and fitted with simple curves which seem to approach the R_e axis with zero slope. Both of these results are in accord with theory. The concept of isovalence has been clarified to allow for the orbital structure of molecules. It appears that the heavier of two isovalent hydrides has the greater R_e. Graphs of R_e for groups of isovalent molecules can be fitted with simple curves.