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[en] There are two sources of parity nonconservation (PNC) in atoms: the electron-nucleus weak interaction and the magnetic interaction of electrons with the nuclear anapole moment. A nuclear anapole moment has recently been observed. This is the first discovery of an electromagnetic moment violating fundamental symmetries--the anapole moment violates parity and charge-conjugation invariance. We describe the anapole moment and how it can be produced. The anapole moment creates a circular magnetic field inside the nucleus. The interesting point is that measurements of the anapole allow one to study parity violation inside the nucleus through atomic experiments. We use the experimental result for the nuclear anapole moment of 133Cs to find the strengths of the parity violating proton-nucleus and meson-nucleon forces. Measurements of the weak charge characterizing the strength of the electron-nucleon weak interaction provide tests of the Standard Model and a way of searching for new physics beyond the Standard Model. Atomic experiments give limits on the extra Z-boson, leptoquarks, composite fermions, and radiative corrections produced by particles that are predicted by new theories. The weak charge and nuclear anapole moment can be measured in the same experiment. The weak charge gives the mean value of the PNC effect while the anapole gives the difference of the PNC effects for the different hyperfine components of an electromagnetic transition. The interaction between atomic electrons and the nuclear anapole moment may be called the ''PNC hyperfine interaction.''
[en] The radium atom is a promising system for studying parity and time invariance violating weak interactions. However, available experimental spectroscopic data for radium are insufficient for designing an optimal experimental setup. We calculate the energy levels and transition amplitudes for radium states of significant interest. Forty states corresponding to all possible configurations consisting of the 7s, 7p and 6d single-electron states as well as the states of the 7s8s, 7s8p and 7s7d configurations have been calculated. The energies of ten of these states corresponding to the 6d2, 7s8s, 7p2 and 6d7p configurations are not known from experiment. Calculations for barium are used to control the accuracy
[en] We present a review of recent works on variation of fundamental constants and violation of parity in atoms and nuclei.Theories unifying gravity with other interactions suggest temporal and spatial variation of the fundamental 'constants' in expanding Universe. The spatial variation can explain fine tuning of the fundamental constants which allows humans (and any life) to appear. We appeared in the area of the Universe where the values of the fundamental constants are consistent with our existence.We describe recent works devoted to the variation of the fine structure constant α, strong interaction and fundamental masses (Higgs vacuum). There are some hints for the variation in quasar absorption spectra, Big Bang nucleosynthesis, and Oklo natural nuclear reactor data.A very promising method to search for the variation consists in comparison of different atomic clocks. Huge enhancement of the variation effects happens in transitions between very close atomic and molecular energy levels. A new idea is to build a 'nuclear' clock based on UV transition in Thorium nucleus. This may allow to improve sensitivity to the variation up to 10 orders of magnitude. Measurements of violation of fundamental symmetries, parity (P) and time reversal (T), in atoms allows one to test unification theories in atomic experiments. We have developed an accurate method of many-body calculations - all-orders summation of dominating diagrams in residual e-e interaction. To calculate QED radiative corrections to energy levels and electromagnetic amplitudes in many-electron atoms and molecules we derived the ''radiative potential'' and the low-energy theorem. This method is simple and can be easily incorporated into any many-body theory approach. Using the radiative correction and many-body calculations we obtained the PNC amplitude EPNC = -0.898(1 ± 0.5%) x 10-11ieaB(-QW/N). From the measurements of the PNC amplitude we extracted the Cs weak charge QW = -72.66(29)exp(36)theor. The difference with the standard model value QWSM = -73.19 is QW - QWSM = 0.53(48)
[en] We present an efficient method of inclusion of the core-valence correlations into the configuration interaction (CI) calculations. These correlations take place in the core area where the potential of external electrons is approximately constant. A constant potential does not change the core electron wave functions and Green's functions. Therefore, all operators describing interaction of M valence electrons and N-M core electrons [the core part of the Hartree-Fock Hamiltonian VN-M, the correlation potential Σ1(r,r',E), and the screening of interaction between valence electrons by the core electrons Σ2] may be calculated with all M valence electrons removed. This allows one to avoid subtraction diagrams which make accurate inclusion of the core-valence correlations for M>2 prohibitively complicated. Then the CI Hamiltonian for M valence electrons is calculated using orbitals in complete VN potential (the mean field produced by all electrons); Σ1+Σ2 are added to the CI Hamiltonian to account for the core-valence correlations. We calculate Σ1 and Σ2 using many-body perturbation theory in which dominating classes of diagrams are included in all orders. We use neutral Xe I and all positive ions up to Xe VIII as a testing ground. We found that the core electron density for all these systems is practically the same. Therefore, we use the same Σ1 and Σ2 to build the CI Hamiltonian in all these systems (M=1,2,3,4,5,6,7,8). Good agreement with experiment for energy levels and Lande factors is demonstrated for all cases from Xe I to Xe VIII
[en] We show that the relative effect of variation of the fine-structure constant in microwave transitions between very close and narrow rotational-hyperfine levels may be enhanced 2-3 orders of magnitude in diatomic molecules with unpaired electrons like LaS, LaO, LuS, LuO, YbF, and similar molecular ions. The enhancement is result of cancellation between the hyperfine and rotational intervals
[en] The relative effects of the variation of the fine structure constant α=e2/(ℎ/2π)c and the dimensionless strong interaction parameter mq/ΛQCD are enhanced by 5-6 orders of magnitude in a very narrow ultraviolet transition between the ground and the first excited states in the 229Th nucleus. It may be possible to investigate this transition with laser spectroscopy. Such an experiment would have the potential of improving the sensitivity to temporal variation of the fundamental constants by many orders of magnitude
[en] We use relativistic Hartree-Fock and configuration-interaction methods to calculate the dependence of transition frequencies for singly ionized cobalt on the fine structure constant. The results are to be used in the search for variation of the fine structure constant in quasar absorption spectra.
[en] The charge density of vector particles, for example W±, may change sign. The effect manifests itself even for a free propagation, when the energy of the W-boson satisfies ε>√(2)m and the standing wave is considered. The charge density of W also changes sign in a vicinity of a Coulomb center. For an arbitrary vector boson (e.g., for spin 1 mesons), this effect depends on the g-factor. An origin of this surprising effect is traced to the electric quadrupole moment and spin-orbit interaction of vector particles; their contributions to the current have a polarization nature. The corresponding charge density equals ρPol=-∇·P, where P is an effective polarization vector that depends on the quadrupole moment and spin-orbit interaction. This density oscillates in space, producing zero contribution to the total charge