552 research outputs found
Mini-Proceedings of ECT Workshop "Strangeness in Nuclei"
This workshop brought together international experts in the research area of
strangeness in nuclei physics, working on theory as well as on experiments, to
discuss the present status, to develop new methods of analysis and to have the
opportunity for brainstorming towards future studies, going towards a deeper
understanding of the hot topics in the low-energy QCD in the strangeness
sector
Are collapse models testable with quantum oscillating systems? The case of neutrinos, kaons, chiral molecules
Collapse models provide a theoretical framework for understanding how
classical world emerges from quantum mechanics. Their dynamics preserves
(practically) quantum linearity for microscopic systems, while it becomes
strongly nonlinear when moving towards macroscopic scale. The conventional
approach to test collapse models is to create spatial superpositions of
mesoscopic systems and then examine the loss of interference, while
environmental noises are engineered carefully. Here we investigate a different
approach: We study systems that naturally oscillate --creating quantum
superpositions-- and thus represent a natural case-study for testing quantum
linearity: neutrinos, neutral mesons, and chiral molecules. We will show how
spontaneous collapses affect their oscillatory behavior, and will compare them
with environmental decoherence effects. We will show that, contrary to what
previously predicted, collapse models cannot be tested with neutrinos. The
effect is stronger for neutral mesons, but still beyond experimental reach.
Instead, chiral molecules can offer promising candidates for testing collapse
models.Comment: accepted by NATURE Scientific Reports, 12 pages, 1 figures, 2 table
Special Issue on Spin Statistics
A workshop dedicated to spin statistics—"SpinStat2008"—was held at the end of October 2008 at the Stazione Marittima Conference Center in Trieste, Italy: it was meant to focus especially on experimental and theoretical aspects of the spin-statistics connection and of related symmetries (in particular the CPT and the Lorentz symmetries). The workshop was quite successful and everybody there felt that there should be a follow-up, and that the many interesting contributions and ideas presented there should be put in paper form. After some thinking we decided that the best format would be a series of refereed papers in a topical issue of an outstanding journal, open to all contributors, rather than the usual volume of conference papers restricted to participants. The Editors of Foundations of Physics kindly accepted to host this topical issue, and the ensuing call for papers drew a respectable flow of interesting and novel ideas, and some very appealing review papers. The comments that follow have bee
Updated analysis of meson-nucleon sigma terms in the perturbative chiral quark model
We present an updated analysis of meson-baryon sigma terms in the
perturbative chiral quark model, which is based on effective chiral Lagrangian.
The new feature concerns the inclusion of excited states in the quark
propagator. Its influence on meson loops is shown to lead in particular for the
pion-nucleon sigma term to an enhancement relevant for the current evaluation
of this quantity. We also determine various flavor combinations of the scalar
nucleon form factors and their respective low-momentum transfer limits.Comment: 26 pages, 10 figures, to be published in Phys Rev
- …