26,022 research outputs found
Brane-World Motion in Compact Dimensions
The topology of extra dimensions can break global Lorentz invariance,singling
out a globally preferred frame even in flat spacetime. Through experiments that
probe global topology, an observer can determine her state of motion with
respect to the preferred frame. This scenario is realized if we live on a brane
universe moving through a flat space with compact extra dimensions. We identify
three experimental effects due to the motion of our universe that one could
potentially detect using gravitational probes. One of these relates to the
peculiar properties of the twin paradox in multiply-connected spacetimes.
Another relies on the fact that the Kaluza-Klein modes of any bulk field are
sensitive to boundary conditions. A third concerns the modification to the
Newtonian potential on a moving brane. Remarkably, we find that even small
extra dimensions are detectable by brane observers if the brane is moving
sufficiently fast
On the Appearance of Families of Efimov States in the Spinor Three-Body Problem
Few-body systems with access to multiple internal levels exhibit richness
beyond that typically found in their single-level counterparts. One example is
that of Efimov states in strongly-correlated spinor three-body systems. In [V.
E. Colussi, C. H. Greene, and J. P. D'Incao, Phys. Rev. Lett. {\bf 113}, 045302
(2014)] this problem was analyzed for spinor condensates finding a complex
level structure as in an early work [Bulgac and Efimov, Sov. J. Nucl. Phys. 22,
153 (1976)] in nuclear physics, and the impact of Efimov physics on the general
form of the scattering observables was worked out. In this paper we discuss the
appearance of novel families of Efimov states in the spinor three-body problem.Comment: Conference proceedings for the 21st International Conference on
Few-Body Problems in Physic
Raising the unification scale in supersymmetry
In the minimal supersymmetric standard model, the three gauge couplings
appear to unify at a mass scale near GeV. We investigate the
possibility that intermediate scale particle thresholds modify the running
couplings so as to increase the unification scale. By requiring consistency of
this scenario, we derive some constraints on the particle content and locations
of the intermediate thresholds. There are remarkably few acceptable solutions
with a single cleanly defined intermediate scale far below the unification
scale.Comment: 22 pages, macros included. One figure, available at
ftp://ftp.phys.ufl.edu/incoming/rais.ep
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