TaN, a molecular system for probingP,T-violating hadron physics

Abstract

All-electron configuration interaction theory in the framework of the Dirac-Coulomb Hamiltonian has been applied to the TaN molecule, a promising candidate in the search for Beyond-Standard-Model physics in both the hadron and the lepton sector of matter. We obtain in the first excited 3 ∆1 state a P, T -odd effective electric field of 36.0 GV cm , a scalar-pseudoscalar P, T -odd interaction constant of 32.8 [kHz], and a nuclear magnetic-quadrupole moment interaction constant of 0.74 [ 10 33 Hz e cm 2 ]. The latter interaction constant has been obtained with a new approach which we describe in detail. Using the same highly correlated all-electron wavefunctions with up to 2.5 billion expansion terms, we obtain a parallel magnetic hyperfine interaction constant of −2954 [MHz] for the 181 Ta nucleus, a very large molecule-frame electric dipole moment of −4.91 [Debye], and spectroscopic constants for the four lowest-lying electronic states of the molecule. arXiv:1512.08729v1 [physics.atom-ph] 1 Nov 2015

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

“…for ThF + the estimate from Ref. [11] differs from that of ab-initio correlation calculation [29] by about 3 times [62] The obtained W M in HfF + is very close to the value of W M in the ThF + [29] and slightly smaller than that in TaN [63,64]. Note, however, that the HfF + cation is already under active investigation for the other T,P-odd effects and similar experimental technique can be used to search for the nuclear MQM.…”

Ω-doubling and a limit for the enhancement of the electron EDM effect in diatomic molecules

“…In this experiment the electron spin rotation angle in an external electric field, arising due to the existence of the electron EDM, was measured. Theoretical calculations for the ThO molecule were given in [29,30]. We should mention also a proposal to measure P, T-odd effects in the ground 3 1 state of WC molecule [31].…”

On the Interplay between Charge‐Shift Bonding and Halogen Bonding

“…Nevertheless, many studies have demonstrated that the quantum calculations should also include the relativistic spin-orbit interaction for At-containing compounds. [42,44,[48][49][50][51][52][53] For instance, the interaction energy of At-mediated XBs can be affected by SOC effects up to 35 %. [26,45,46] Hence, all these systems have been additionally investigated through twocomponent (2c) relativistic calculations.…”

“…Indeed, astatine is to date the heaviest halogen element and the most polarisable one. [42] It is therefore appealing to probe the XB interaction in Y 3 CÀ X···Z À systems from the perspective of the most potent XB-donor element. Astatine (Z=85) is a radioelement whose second long-lived isotope, At-211, has been recently identified as being of high potential interest for nuclear medicine applications.…”