0000000000183515
AUTHOR
W. Thiel
Ab Initio Calculations and High-Resolution Spectroscopy of the Bending Pentad of SiH2D2 in the 10–16 um Region
International audience; The SiH2D2 asymmetric top has nine vibrational modes, five of them forming a pentad strongly perturbed by Coriolis interactions. High-level ab initio calculations of SiH2D2 have been performed which yield numerous spectroscopic parameters related to the harmonic and anharmonic force fields. The bending pentad comprising v4(A1), v7(B1), v5(A2), v9(B2), and v3(A1) has been studied by high-resolution Fourier transform spectroscopy; the region 600 –1050 cm-1 has been investigated with a resolution of ca. 4 x 10-3 cm-1. Raman BOXCARS spectroscopy has been used for the infrared inactive v5 band. The Raman apparatus function was 0.0054 cm-1. Assignments of about 4000 transi…
Measurement of the spin-dependent structure function g1(x) of the deuteron
We report on the first measurement of the spin-dependent structure function g1d of the deuteron in the deep inelastic scattering of polarised muons off polarised deuterons, in the kinematical range 0.006<x<0.6, 1 GeV2<Q2<30 GeV2. The first moment, Γ1d=sh{phonetic}01 g1d dx=0.023±0.020 (stat.) ± 0.015 (syst.), is smaller than the prediction of the Ellis-Jaffe sum rules. Using earlier measurements of g1p, we infer the first moment of the spin-dependent neutron structure function g1n. The difference Γ1p-Γ1n=0.20 ±0.05 (stat.) ± 0.04 (syst.) agrees with the prediction of the Bjorken sum rule, Γ1p-Γ1n=0.191 ±0.002.