Theoretical study of thorium monoxide for the electron electric dipole moment search: Electronic properties of H3Δ1 in ThO

Abstract

Recently, improved limits on the electron electric dipole moment, and dimensionless constant, kT,P, characterizing the strength of the T,P-odd pseudoscalar-scalar electron-nucleus neutral current interaction in the H(3)Δ1 state of ThO molecule were obtained by the ACME collaboration [J. Baron et al., Science 343, 269 (2014)]. The interpretation of the experiment in terms of these fundamental quantities is based on the results of theoretical study of appropriate ThO characteristics, the effective electric field acting on electron, Eeff, and a parameter of the T,P-odd pseudoscalar-scalar interaction, WT,P, given in Skripnikov et al. [J. Chem. Phys. 139, 221103 (2013)] by St. Petersburg group. To reduce the uncertainties of the given limits, we report improved calculations of the molecular state-specific quantities Eeff, 81.5 GV/cm, and WT,P, 112 kHz, with the uncertainty within 7% of the magnitudes. Thus, the values recommended to use for the upper limits of the quantities are 75.8 GV/cm and 104 kHz, correspondingly. The hyperfine structure constant, molecule-frame dipole moment of the H(3)Δ1 state, and the H(3)Δ1 → X(1)Σ(+) transition energy which, in general, can serve as a measure of reliability of the obtained Eeff and WT,P values are also calculated. In addition, we report the first calculation of g-factor for the H(3)Δ1 state of ThO. The results are compared to the earlier experimental and theoretical studies, and a detailed analysis of uncertainties of the calculations is given.

Enhanced effect of CP -violating nuclear magnetic quadrupole moment in a HfF+ molecule

“…The procedure has been recently extended to consider not only the atomic and molecular systems but also three-dimensional periodic structures (crystals) in Ref. [39]. GRECP and the restoration procedure were also successfully used for precise investigation of different diatomics [7,29,[40][41][42][43][44][45][46][47][48][49].…”

TaN molecule as a candidate for the search for aT,P-violating nuclear magnetic quadrupole moment

“…There is a number of systems on which experiments to search for T,P-odd effects have already been conducted or suggested and which are investigated theoretically and experimentally (HfF + [12][13][14][15][16][17][18], YbF [2,[19][20][21][22][23][24][25], ThO [3,[26][27][28][29][30][31], ThF + [13,32], WC [33,34], PbF [35][36][37][38], RaO [39,40], RaF [41,42], PtH + [16,43], etc.). Recently, TaN molecule was suggested as a new system to search for the T,P-odd MQM of the tantalum nucleus [44], where the molecule was marked as quite promising candidate to search for T,P violation in nuclear sector using molecules.…”

Stimulated Raman adiabatic passage preparation of a coherent superposition of ThOH3Δ1states for an improved electron electric-dipole-moment measurement

“…The measurement took advantage of the high effective electric field E eff ≈ 78 GV/cm of the metastable ThO H 3 1 state, when the molecules are fully polarized in moderate electric fields (∼ 10 V/cm) [15][16][17]. The use of the H 3 1 state allows for spectroscopic reversal of E eff in the laboratory frame due to its -doublet structure [18].…”