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

Time-Reversal-Violating Schiff Moment of 199Hg

We calculate the Schiff moment of the nucleus 199Hg, created by pi-N-N vertices that are odd under parity (P) and time-reversal (T). Our approach, formulated in diagrammatic perturbation theory with important core-polarization diagrams summed to all orders, gives a close approximation to the expectation value of the Schiff operator in the odd-A Hartree-Fock-Bogoliubov ground state generated by a Skyrme interaction and a weak P- and T-odd pion-exchange potential. To assess the uncertainty in the results, we carry out the calculation with several Skyrme interactions (the quality of which we test by checking predictions for the isoscalar-E1 strength distribution in 208Pb) and estimate most of the important diagrams we omit.Comment: 13 pages, 7 figure

Basic research on liquid-drop-impact erosion Quarterly report, 8 Dec. 1966 - 8 Mar. 1967

Liquid drop impact erosion - single impact helium driven gas gun, target materials, and elastic wave theory applied to impact of rod

Basic research on liquid-drop-impact erosion

Liquid drop impact erosion in metals and equation for crater dept

Work distribution for the driven harmonic oscillator with time-dependent strength: Exact solution and slow driving

We study the work distribution of a single particle moving in a harmonic oscillator with time-dependent strength. This simple system has a non-Gaussian work distribution with exponential tails. The time evolution of the corresponding moment generating function is given by two coupled ordinary differential equations that are solved numerically. Based on this result we study the behavior of the work distribution in the limit of slow but finite driving and show that it approaches a Gaussian distribution arbitrarily well

Bargaining in the Absence of Property Rights. An Experiment

The Coase theorem posits that if (1) property rights are perfect, (2) contracts are perfectly enforceable, (3) transaction costs are zero, (4) preferences are common knowledge, and (5) parties are rational, then the initial allocation of entitlements matters only for distribution, not for efficiency. We study, in an experimental setting, whether condition 1 is necessary. Our results suggest that property rights have a limited effect on efficiency

Probing Single-Electron Spin Decoherence in Quantum Dots using Charged Excitons

We propose to use optical detection of magnetic resonance (ODMR) to measure the decoherence time T 2 of a single-electron spin in a semiconductor quantum dot. The electron is in one of the spin 1/2 states and a circularly polarized laser can only create an optical excitation for one of the electron spin states due to Pauli blocking. An applied electron spin resonance (ESR) field leads to Rabi spin flips and thus to a modulation of the photoluminescence or, alternatively, of the photocurrent. This allows one to measure the ESR linewidth and the coherent Rabi oscillations, from which the electron spin decoherence can be determined. We study different possible schemes for such an ODMR setup, including cw or pulsed laser excitatio

Perturbative description of nuclear double beta decay transitions

A consistent treatment of intrinsic and collective coordinates is applied to the calculation of matrix elements describing nuclear double beta decay transitions. The method, which was developed for the case of nuclear rotations, is adapted to include isospin and number of particles degrees of freedom. It is shown that the uncertainties found in most models, in dealing with these decay modes, are largely due to the mixing of physical and spurious effects in the treatment of isospin dependent interactions.Comment: 4 pages, 2 figures, RevTe