39,228 research outputs found
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
The School-to-Prison Pipeline’s Legal Architecture: Lessons from the Spring Valley Incident and Its Aftermath
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 or its CP conjugate is shown to be a
necessary condition for obtaining different CP asymmetries in . 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 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 Standard Model amplitude hierarchy could be ruled out with
more precise data. (c) A slowly falling form factor can be
ruled out using the spectrum obtained by ARGUS at the . The decay is therefore highly suppressed and the
origin of the anomalously large rate remains unknown,
perhaps requiring the intervention of New Physics.Comment: 12 pages, 3 figure
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
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