154 research outputs found
Language of Lullabies: The Russification and De-Russification of the Baltic States
This article argues that the laws for promotion of the national languages are a legitimate means for the Baltic states to establish their cultural independence from Russia and the former Soviet Union
A limiting velocity for quarkonium propagation in a strongly coupled plasma via AdS/CFT
We study the dispersion relations of mesons in a particular hot strongly
coupled supersymmetric gauge theory plasma. We find that at large momentum k
the dispersion relations become omega = v_0 k + a + b/k + ..., where the
limiting velocity v_0 is the same for mesons with any quantum numbers and
depends only on the ratio of the temperature to the quark mass T/m_q. We
compute a and b in terms of the meson quantum numbers and T/m_q. The limiting
meson velocity v_0 becomes much smaller than the speed of light at temperatures
below but close to T_diss, the temperature above which no meson bound states at
rest in the plasma are found. From our result for v_0, we find that the
temperature above which no meson bound states with velocity v exist is
T_diss(v) \simeq (1-v^2)^(1/4) T_diss, up to few percent corrections.We thus
confirm by direct calculation of meson dispersion relations a result inferred
indirectly in previous work via analysis of the screening length between a
static quark and antiquark in a moving plasma. Although we do not do our
calculations in QCD, we argue that the qualitative features of the dispersion
relation we compute, including in particular the relation between dissociation
temperature and meson velocity, may apply to bottomonium and charmonium mesons
propagating in the strongly coupled plasma of QCD. We discuss how our results
can contribute to understanding quarkonium physics in heavy ion collisions.Comment: 57 pages, 12 figures; references adde
Deformation Quantization of Superintegrable Systems and Nambu Mechanics
Phase Space is the framework best suited for quantizing superintegrable
systems, naturally preserving the symmetry algebras of the respective
hamiltonian invariants. The power and simplicity of the method is fully
illustrated through new applications to nonlinear sigma models, specifically
for de Sitter N-spheres and Chiral Models, where the symmetric quantum
hamiltonians amount to compact and elegant expressions. Additional power and
elegance is provided by the use of Nambu Brackets to incorporate the extra
invariants of superintegrable models. Some new classical results are given for
these brackets, and their quantization is successfully compared to that of
Moyal, validating Nambu's original proposal.Comment: LateX2e, 18 page
Hadron Spectroscopy: Theory and Experiment
Many new results on hadron spectra have been appearing in the past few years
thanks to improved experimental techniques and searches in new channels. New
theoretical techniques including refined methods of lattice QCD have kept pace
with these developments. Much has been learned about states made of both light
(u, d, and s) and heavy (c, b) quarks. The present review treats light-quark
mesons, glueballs, hybrids, particles with a single c or b quark, charmonium,
and bottomonium states. Some prospects for further study are noted.Comment: 29 pages, 9 figures, to be published in Journal of Physics G. Further
updating of reference
Hobby Lobby, Birth Control and Our Ongoing Cultural Wars: Pleasure and Desire in the Crossfires
Taking a Bite at the Apple: Ensuring a Level-Playing-Field for Competition on App Stores
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