Efimov physics beyond three particles

Efimov physics originally refers to a system of three particles. Here we review recent theoretical progress seeking for manifestations of Efimov physics in systems composed of more than three particles. Clusters of more than three bosons are tied to each Efimov trimer, but no independent Efimov physics exists there beyond three bosons. The case of a few heavy fermions interacting with a lighter atom is also considered, where the mass ratio of the constituent particles plays a significant role. Following Efimov's study of the (2+1) system, the (3+1) system was shown to have its own critical mass ratio to become Efimovian. We show that the (4+1) system becomes Efimovian at a mass ratio which is smaller than its sub-systems thresholds, giving a pure five-body Efimov effect. The (5+1) and (6+1) systems are also discussed, and we show the absence of 6- and 7-body Efimov physics there

Physics of dark energy particles

We consider the astrophysical and cosmological implications of the existence of a minimum density and mass due to the presence of the cosmological constant. If there is a minimum length in nature, then there is an absolute minimum mass corresponding to a hypothetical particle with radius of the order of the Planck length. On the other hand, quantum mechanical considerations suggest a different minimum mass. These particles associated with the dark energy can be interpreted as the ``quanta'' of the cosmological constant. We study the possibility that these particles can form stable stellar-type configurations through gravitational condensation, and their Jeans and Chandrasekhar masses are estimated. From the requirement of the energetic stability of the minimum density configuration on a macroscopic scale one obtains a mass of the order of 10^55 g, of the same order of magnitude as the mass of the universe. This mass can also be interpreted as the Jeans mass of the dark energy fluid. Furthermore we present a representation of the cosmological constant and of the total mass of the universe in terms of `classical' fundamental constants.Comment: 10 pages, no figures; typos corrected, 4 references added; 1 reference added; reference added; entirely revised version, contains new parts, now 14 page

Noncommutative field theories with harmonic term

The UV-IR mixing of scalar field theory on the Moyal space is removed by the harmonic term, so that the theory is renormalizable. We will present different properties of this scalar model and its associated gauge theory, which is candidate to renormalizability. The supergeometric interpretation of the harmonic term, for both scalar and gauge models, and related to the Langmann-Szabo duality, will be exposed.Comment: 12 pages, Contribution to the proceedings of the Corfu Summer Institute on Elementary Particles and Physics 2011, v2: some references adde

Physics of windblown particles

A laboratory facility proposed for the Space Station to investigate fundamental aspects of windblown particles is described. The experiments would take advantage of the environment afforded in earth orbit and would be an extension of research currently being conducted on the geology and physics of windblown sediments on earth, Mars, and Venus. Aeolian (wind) processes are reviewed in the planetary context, the scientific rational is given for specific experiments to be conducted, the experiment apparatus (the Carousel Wind Tunnel, or CWT) is described, and a plan presented for implementing the proposed research program

Constraining new physics in the Tev range by the recent BNL measurement of (g-2)_{\mu}

In this paper we study the implications of the recent high precision measurement of (g-2)_{\mu} by BNL on new heavy physics beyond the SM in a model independent way. We find that if the new physics responsible for the muon anomaly is due to d=6 direct operators then they could arise from the following follwing three broad classes of new physics a) new particles in the few hundred Gev range with weak gauge coupling b) strongly interacting particles and resonances in the few Tev range and c) massive Kaluza-Klein modes of the graviton in the Tev range with couplings to SM particles of the order of ${E\over (Tev)}$.Comment: Final version to be published in Physics Letters

Physics and Mathematics of Calogero particles

We give a review of the mathematical and physical properties of the celebrated family of Calogero-like models and related spin chains.Comment: Version to appear in Special Issue of Journal of Physics A: Mathematical and Genera