Communication: Electric dipole moment and hyperfine interaction of tungsten monocarbide, WC

Abstract

The [17.6]2← X3Δ1(1,0) band of tungsten monocarbide, WC, was recorded using laser induced fluorescence both field-free and in the presence of a static electric field. The Stark induced shifts of the R(1) and Q(2) lines were analyzed to produce values for the permanent electric dipole moments, μ, of 3.90 ± 0.04 D and 2.57 ± 0.04 D for the X3Δ1(v = 0) and [17.6]2(v = 1) states, respectively. An upper limit to the Ω-doubling parameter, $\tilde o_\Delta$õΔ, of 2 MHz is established. The 183W(I = 1/2) Fermi contact parameter, bF, for the X3Δ1(v = 0) is estimated to be 1363 MHz. The results are compared with theoretical predictions and a molecular orbital correlation description.

Optical spectroscopy of tungsten carbide for uncertainty analysis in electron electric-dipole-moment search

“…We report the measured hyperfine constants of h3 ∆1,v"=0 and h [20.6]Ω=2,v ′ =4 in Table V. For the hyperfine constant of 3 ∆ 1 , v" = 0 state, we compare our result with the previous results of Wang's [15], which had a slightly larger uncertainty then our case. As seen from Table V, our result of h3 ∆1 had good agreement with the theoretical calculation, however, disagreed with ref.…”

“…In order to analyze these uncertainties, here we have studied the [20.6]Ω = 2, v ′ = 4 ← X 3 ∆ 1 , v" = 0 transition of WC by laser induced fluorescence(LIF) spectroscopy on a pulsed supersonic jet of WC molecules. The optical properties of WC have been studied both theoretically [11,12] and experimentally [13][14][15][16][17]. We had ∼ 100 times higher spectral resolution than the previous resonant two-photon ionization(R2PI) spectroscopy of the same transition [13].…”

Electron electric dipole moment and hyperfine interaction constants for ThO

“…It has been argued that the EDM effective electric field is predominantly a core property [21] and thus could be sensitive to the correlated movement of the inner-shell electrons of the respective heavy atom. Table II suggests that these correlation contributions [20] are negligible, at least for the ThO molecule.…”

Theoretical study on ThF+, a prospective system in search of time-reversal violation

“…What the afore-mentioned molecules, and several others such as HfH + , PtH + [19] and WC [20,21], have in common is an energetically low-lying Δ 3 electronic state (in Λ-S coupling picture). In the fluorides and oxides this state is deeply bound which is an experimental advantage.…”