arXiv subjects

Mikhail Kozlov

Publications and source records attributed to Mikhail Kozlov.

5 recordsLinked to original sources

arXiv2017

Constraints on exotic spin-dependent interactions between electrons from helium fine-structure spectroscopy

Agreement between theoretical calculations of atomic structure and spectroscopic measurements is used to constrain possible contribution of exotic spin-dependent interactions between electrons to the energy differences between states in helium-4. In particular, constraints on dipole-dipole interactions associated with the exchange of pseudoscalar bosons (such as axions or axion-like particles, ALPs) with masses $10^{-2}~{\rm eV} \lesssim m \lesssim 10^{4}~{\rm eV}$ are improved by a factor of $\sim 100$. The first atomic-scale constraints on several exotic velocity-dependent dipole-dipole interactions are established as well.

physics.atom-ph↗

arXiv2015

TaN, a molecular system for probing ${\cal{P,T}}$-violating hadron physics

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 {$^3Δ_1$} state a ${\cal{P,T}}$-odd effective electric field of $36.0 \left[\frac{\rm GV}{\rm cm}\right]$, a scalar-pseudoscalar ${\cal{P,T}}$-odd interaction constant of $32.8$ [kHz], and a nuclear magnetic-quadrupole moment interaction constant of $0.74$ [$\frac{10^{33} {\text{Hz}}}{e\, {\text{cm}}^2}$]. 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 $\rm {^{181}{T}a}$ 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.

physics.atom-ph↗

arXiv2002

Manifestation of the Nuclear Anapole Moment in M1 Transitions in Thallium

We calculate nuclear spin-dependent parity non-conserving $E1$-amplitudes for optical transition $6p_{1/2,F} -> 6p_{3/2,F'}$ and for hyperfine transition $6p_{1/2,F} -> 6p_{1/2,F'}$ in Tl. Experimental limit on the former amplitude placed by Vetter et al. [PRL, 74, 2658 (1995)] corresponds to the anapole moment constant $κ_a = -0.26 \pm 0.27$. Experiment on the hyperfine transition can give direct measurement of the spin-dependent amplitude, because spin-independent amplitude turns to zero.

physics.atom-ph↗

arXiv1998

Stark-Induced Electric Dipole Amplitudes for Hyperfine Transitions

Stark-induced electric dipole amplitudes between states of the same nominal parity can be important in experiments to observe parity nonconservation in atoms. The Stark-induced E1 amplitudes are expressed in terms of an irreducible spherical-tensor decomposition. This formalism is applied to the specific case of transitions between hyperfine sublevels of a single atomic state. It is shown that in the ground states of alkali atoms, such transitions are suppressed by many orders of magnitude relative to naive expectations.

physics.atom-ph↗

arXiv1997

Enhancement of the electric dipole moment of the electron in the YbF molecule

We calculate an effective electric field on the unpaired electron in the YbF molecule. This field determines sensitivity of the molecular experiment to the electric dipole moment of the electron. We use experimental value of the spin-doubling constant to estimate the admixture of the configuration with the hole in the 4f-shell of Ytterbium to the ground state of the molecule. This admixture reduces the field by 7%. Our value for the effictive field is 5.1 a.u. = 2.5 10^{10} V/cm.

physics.atom-ph↗