Rotation-vibration spectrum of HT: Line position measurements of the 1-0, 4-0, and 5-0 bands

Optoacoustic techniques have been used to determine the line positions of the 1-0 fundamental and 4-0 and 5-0 overtones of the HT (¹H³H) molecule with an accuracy of better than 0.01 cm⁻¹. Comparison with line positions predicted from ab initio calculations that include adiabatic, relativistic, radiative, and nonadiabatic corrections shows disagreement outside of the experimental uncertainties.     

Infra-red absorption bands 1-0, 2-0, 3-0 and 4-0 of the two isotopic species D79Br and D81Br of deuterium bromide

High resolution spectra of the 1-0, 2-0, 3-0, and 4-0 infra-red absorption bands of the two isotopic species of deuterium bromide have been recorded up to very high J values. The equilibrium molecular parameters obtained in the analysis fit the 267 observed lines within their experimental uncertainties, and give precise calculated wavenumbers for some observed chemical laser lines of these molecules.     

Absolute wavenumber measurements of 1-0, 2-0, HF and 2-0, H35Cl,H37Cl absorption bands

Fourier absorption spectra of HCl and HF at room temperature permitted to measure 87 absolute wavenumbers. The absolute observed position of the P(6) line of the 1-0 band of HF is not in agreement with a recent heterodyne determination [3]. It is found equal to 110 725 739 ± 7.5 MHz.     

Adsorption, ordering, and chemistry of nitrobenzene on Si(1 0 0)-2 × 1

Surface chemistry of nitrobenzene on Si(1 0 0)-2 × 1 has been investigated using multiple internal reflection Fourier-transform infrared spectroscopy (MIR-FTIR), Auger electron spectroscopy (AES) and thermal desorption mass spectrometry. Molecular adsorption of nitrobenzene at submonolayer coverages is dominating at cryogenic temperatures (100 K). As the surface temperature is increased to 160 K, chemical reaction involving nitro group occurs, while the phenyl entity remains intact. Thus, a barrier of approximately 40.8 kJ/mol is established for the interaction of the nitro group of nitrobenzene with the Si(1 0 0)-2 × 1 surface. Further annealing of the silicon surface leads to the decomposition of nitrobenzene. The concentration of nitrogen and oxygen remains constant on a surface within the temperature interval studied here. AES studies also suggest that the majority of carbon-containing products remain bound to the surface at temperatures as high as 1000 K. The only chemical reaction leading to the release of the gaseous products is benzene formation around 670 K. The amount of benzene accounts only for a few percent of the surface species, while the rest of the phenyl groups connected to the silicon surface via a nitrogen linker remain stable even at elevated temperatures, opening an opportunity for stable surface coatings.     

Absolute frequency measurements of the 0002-0000, 2001-0000, and 1201-0000 bands of N2O by heterodyne spectroscopy

The absolute frequencies of 39 lines in the 00⁰2-00⁰0, 20⁰1-00⁰0, and 12⁰1-00⁰0 bands of N₂O in the range 4300–4800 cm^?1 have been measured by heterodyne frequency techniques. The lines were each measured in Doppler-limited absorption, with a color-center laser as a tunable probe of the N₂O and two stabilized CO₂ lasers as reference frequencies. New rovibrational constants have been fitted to these measurements. Tables of calculated transition frequencies are given, with estimated absolute uncertainties as small as 10^?4 cm^?1. The pressure shifts of four lines have been measured, and the values fall within the range of 0 to ?2 MHz/kPa (0 to ?0.2 MHz/Torr).     

Rotational Analysis of the 0-0 and 1-0 B-X Bands of Ga18O Molecules

The B²Σ⁺-X^{2 +} system of the ⁶⁹Ga¹⁸O and ⁷¹Ga¹⁸O molecules excited in a low-pressure arc, has been recorded in the region between 300 and 500 nm. The 0-0 and 1-0 bands of both molecular species have been rotationally analyzed and the molecular constants of involved states have been derived.     

Mixing and CP violation: fromB^0 - \overline {B^0 } to T^0 - \overline {T^0 }

We extend from \(B^0 - \overline {B^0 } to T^0 - \overline {T^0 } \) the study of neutral pseudoscalar mesons with respect to mixing and CP violation. The possibility of a quite large top quark mass necessitates a more careful computation of the box diagram amplitude. Our result is that, while in \(B^0 - \overline {B^0 } \) systems CP violation is expected to be very small (～10^?6) and mixing quite large (10–20% or more), precisely the opposite occurs for \( T^0 - \overline {T^0 } \) . In particular, CP violation in the \( T_u^0 - \overline {T_u^0 } \) system could be of the same order of magnitude as in the \(K^0 - \overline {K^0 } \) system (～10^?3) while the mixing is totally negligible.     

Absorption intensities for the 4-0 through 7-0 overtone bands of HCl

We have measured the absorption intesities for a number of rotation-vibration lines in the 4-0 through 7-0 overtone bands of HCl utilizing a Fourier transform spectrometer and a 409.6 m path length White cell. Individual line strengths, band strengths, dipole matrix elements, and Herman-Wallis factors are presented.     

The infrared and microwave spectra of ozone for the (0, 0, 0), (1, 0, 0), and (0, 0, 1) states

New measurements of the ozone spectrum in the microwave and 10-μm infrared regions have been made. These new lines have been fit to a three-state Hamiltonian model which includes Coriolis interactions beteen (0, 0, 1) and (1, 0, 0). The model requires additional Coriolis parameters, as well as an appreciation for the parameters which are indeterminate. Transition dipole moments have been derived from the intensities of selected infrared lines.