1,003 research outputs found
Nuclear time-reversal violation and the Schiff moment of 225Ra
We present a comprehensive mean-field calculation of the Schiff moment of the
nucleus 225Ra, the quantity which determines the static electric dipole moment
of the corresponding atom if time-reversal (T) invariance is violated in the
nucleus. The calculation breaks all possible intrinsic symmetries of the
nuclear mean field and includes, in particular, both exchange and direct terms
from the full finite-range T-violating nucleon-nucleon interaction, and the
effects of short-range correlations. The resulting Schiff moment, which depends
on three unknown T-violating pion-nucleon coupling constants, is much larger
than in 199Hg, the isotope with the best current experimental limit on its
atomic electric-dipole moment.Comment: 4 pages, 2 figures; this version (references added) to be published
in PR
Screening and finite size corrections to the octupole and Schiff moments
Parity (P) and time reversal (T) violating nuclear forces create P, T -odd
moments in expansion of the nuclear electrostatic potential. We derive
expression for the nuclear electric octupole field which includes the electron
screening correction (similar to the screening term in the Schiff moment). Then
we calculate the Z alpha corrections to the Schiff moment which appear due to
the finite nuclear size. Such corrections are important in heavy atoms with
nuclear charge Z > 50. The Schiff and octupole moments induce atomic electric
dipole moments (EDM) and P, T -odd interactions in molecules which are measured
in numerous experiments to test CP-violation theories
Conductance anomalies in a one-dimensional quantum contact
Short length quantum wires (quantum contacts) exhibit a conductance structure
at the value of conductance close to 0.7 \times 2e^2/h. The structure is also
called the conductance anomaly. In longer contacts the structure evolves to the
lower values of conductance. We demonstrate that this structure is related to
the development of charge density waves within the contact. This is a precursor
for Wigner crystallization. Many-body Hartree-Fock calculations of conductance
are performed. The results are in agreement with experimental data.Comment: 11 pages, 10 Fig
Relativistic corrections to the nuclear Schiff moment
Parity and time invariance violating (-odd) atomic electric dipole
moments (EDM) are induced by interaction between atomic electrons and nuclear
-odd moments which are produced by -odd nuclear forces. The nuclear
EDM is screened by atomic electrons. The EDM of a non-relativistic atom with
closed electron subshells is induced by the nuclear Schiff moment. For heavy
relativistic atoms EDM is induced by the nuclear local dipole moments which
differ by 10-50% from the Schiff moments calculated previously.
We calculate the local dipole moments for and where the most accurate atomic and molecular EDM measurements have been
performed.Comment: 3 pages, no figures, brief repor
Extension of the Schiff theorem to ions and molecules
According to the Schiff theorem the nuclear electric dipole moment (EDM) is
screened in neutral atoms. In ions this screening is incomplete. We extend a
derivation of the Schiff theorem to ions and molecules. The finite nuclear size
effects are considered including Z^2 alpha^2 corrections to the nuclear Schiff
moment which are significant in all atoms and molecules of experimental
interest. We show that in majority of ionized atoms the nuclear EDM
contribution to the atomic EDM dominates while in molecules the contribution of
the Schiff moment dominates. We also consider the screening of electron EDM in
ions
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