848,687 research outputs found

### 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

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