Influence of Cooper pairing on the inelastic processes in a gas of Fermi atoms

Correlation properties in ultracold Fermi gas with negative scattering length and its impact on the three-body recombination is analyzed. We find that Cooper pairing enhances the recombination rate in contrast to the decrease of this rate accompanying Bose-Einstein condensation in a Bose gas. This trend is characteristic for all interval of temperatures T<Tc

For Hierarchy in Animal Ethics

In my forthcoming book, How to Count Animals, More or Less (based on my 2016 Uehiro Lectures in Practical Ethics), I argue for a hierarchical approach to animal ethics according to which animals have moral standing but nonetheless have a lower moral status than people have. This essay is an overview of that book, drawing primarily from selections from its beginning and end, aiming both to give a feel for the overall project and to indicate the general shape of the hierarchical position that I defend there. In this essay, I contrast the hierarchical approach with its most important rival (which holds that people and animals have the very same moral status), sketch the main idea behind one central argument for hierarchy, and briefly review three potentially troubling implications of the hierarchical view. I close with a discussion of a promising possible solution to the most worrisome of the three objections

Condensation of phonons in an ultracold Bose gas

We consider the generation of longitudinal phonons in an elongated Bose-condensed gas at zero temperature due to parametric resonance as a result of the modulation of the transverse trap frequency. The nonlinear temporal evolution with account of the phonon-phonon interaction leads self-consistently to the formation of the stationary state with the macroscopic occupation of a single phonon quantum state.Comment: 5 pages, 1 figure, submitted to Phys.Rev.Letter

Beyond the Standard Model in B Decays: Three Topics

Three new results are discussed: (a) A non-vanishing amplitude for the `wrong sign{'} kaon decay $B \to J/\Psi \bar{K}$ or its CP conjugate is shown to be a necessary condition for obtaining different CP asymmetries in $B \to J/\Psi K_{S,L}$. A significant effect would require a scale of new physics far below the weak scale, all but ruling out this possibility. (b) The leading isospin breaking contributions to the $B \to K^* \gamma$ decay amplitudes can be calculated in QCD factorization, providing a sensitive probe of the penguin sector of the effective weak Hamiltonian. New physics models which reverse the predicted $10-20$ Standard Model amplitude hierarchy could be ruled out with more precise data. (c) A slowly falling $g^* g \eta^\prime$ form factor can be ruled out using the $\eta^\prime$ spectrum obtained by ARGUS at the $\Upsilon (1S)$. The decay $b \to s g \eta^\prime$ is therefore highly suppressed and the origin of the anomalously large $B \to \eta^\prime X_s$ rate remains unknown, perhaps requiring the intervention of New Physics.Comment: 12 pages, 3 figure

Importance of small earthquakes for stress transfers and earthquake triggering

We estimate the relative importance of small and large earthquakes for static stress changes and for earthquake triggering, assuming that earthquakes are triggered by static stress changes and that earthquakes are located on a fractal network of dimension D. This model predicts that both the number of events triggered by an earthquake of magnitude m and the stress change induced by this earthquake at the location of other earthquakes increase with m as \~10^(Dm/2). The stronger the spatial clustering, the larger the influence of small earthquakes on stress changes at the location of a future event as well as earthquake triggering. If earthquake magnitudes follow the Gutenberg-Richter law with b>D/2, small earthquakes collectively dominate stress transfer and earthquake triggering, because their greater frequency overcomes their smaller individual triggering potential. Using a Southern-California catalog, we observe that the rate of seismicity triggered by an earthquake of magnitude m increases with m as 10^(alpha m), where alpha=1.00+-0.05. We also find that the magnitude distribution of triggered earthquakes is independent of the triggering earthquake magnitude m. When alpha=b, small earthquakes are roughly as important to earthquake triggering as larger ones. We evaluate the fractal correlation dimension of hypocenters D=2 using two relocated catalogs for Southern California, and removing the effect of short-term clustering. Thus D=2alpha as predicted by assuming that earthquake triggering is due to static stress. The value D=2 implies that small earthquakes are as important as larger ones for stress transfers between earthquakes.Comment: 14 pages, 7 eps figures, latex. In press in J. Geophys. Re

Deterrence Misapplied: Challenges in Containing a Nuclear Iran

Argues against relying on deterrence against a nuclear Iran by analyzing problems with the disproportionate focus on Iran's current leadership in debates over deterrence strategies and considering the implications of various doctrines of deterrence