932 research outputs found

### Calculation of nuclear-spin-dependent parity nonconservation in s-d transitions of Ba$^+$, Yb$^+$ and Ra$^+$ ions

We use correlation potential and many-body perturbation theory techniques to
calculate spin-independent and nuclear spin-dependent parts of the parity
nonconserving amplitudes of the transitions between the $6s_{1/2}$ ground state
and the $5d_{3/2}$ excited state of Ba$^+$ and Yb$^+$ and between the
$7s_{1/2}$ ground state and the $6d_{3/2}$ excited state of Ra$^+$. The results
are presented in a form convenient for extracting of the constants of
nuclear-spin-dependent interaction (such as, e.g., anapole moment) from the
measurements.Comment: 9 pages, 8 tables, no figure

### Statistical Theory of Finite Fermi-Systems Based on the Structure of Chaotic Eigenstates

The approach is developed for the description of isolated Fermi-systems with
finite number of particles, such as complex atoms, nuclei, atomic clusters etc.
It is based on statistical properties of chaotic excited states which are
formed by the interaction between particles. New type of ``microcanonical''
partition function is introduced and expressed in terms of the average shape of
eigenstates $F(E_k,E)$ where $E$ is the total energy of the system. This
partition function plays the same role as the canonical expression
$exp(-E^{(i)}/T)$ for open systems in thermal bath. The approach allows to
calculate mean values and non-diagonal matrix elements of different operators.
In particular, the following problems have been considered: distribution of
occupation numbers and its relevance to the canonical and Fermi-Dirac
distributions; criteria of equilibrium and thermalization; thermodynamical
equation of state and the meaning of temperature, entropy and heat capacity,
increase of effective temperature due to the interaction. The problems of
spreading widths and shape of the eigenstates are also studied.Comment: 17 pages in RevTex and 5 Postscript figures. Changes are RevTex
format (instead of plain LaTeX), minor misprint corrections plus additional
references. To appear in Phys. Rev.

### Schiff Theorem Revisited

We carefully rederive the Schiff theorem and prove that the usual expression
of the Schiff moment operator is correct and should be applied for calculations
of atomic electric dipole moments. The recently discussed corrections to the
definition of the Schiff moment are absent.Comment: 6 page

### Variation of fundamental constants in space and time: theory and observations

Review of recent works devoted to the temporal and spatial variation of the
fundamental constants and dependence of the fundamental constants on the
gravitational potential (violation of local position invariance) is presented.
We discuss the variation of the fine structure constant $\alpha=e^2/\hbar c$,
strong interaction and fundamental masses (Higgs vacuum), e.g. the
electron-to-proton mass ratio $\mu=m_e/M_p$ or $X_e=m_e/\Lambda_{QCD}$ and
$X_q=m_q/\Lambda_{QCD}$. We also present new results from Big Bang
nucleosynthesis and Oklo natural nuclear reactor data and propose new
measurements of enhanced effects in atoms, nuclei and molecules, both in quasar
and laboratory spectra.Comment: Proceeding of ACFC, BadHonnef, 2007: to be published in EP

### Comment on "Black hole constraints on varying fundamental constants"

In the Letter [1] (also [2]) there is a claim that the generalised second law
of thermodynamics (entropy increase) for black holes provides some limits on
the rate of variation of the fundamental constants of nature (electric charge
e, speed of light c, etc.). We have come to a different conclusion. The results
in [1,2] are based on assumption that mass of a black hole does not change
without radiation and accreation. We present arguments showing that this
assumption is incorrect and give an estimate of the black hole mass variation
due to alpha=e^2/\hbar c variation using entropy (and quantum energy level)
conservation in an adiabatic process. No model-independent limits on the
variation of the fundamental constants are derived from the second law of
thermodynamics.Comment: Comment on arXiv:0706.2188 [PRL 99, 061301] by Jane MacGibbo

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