20,889 research outputs found
Magnetic Component of Quark-Gluon Plasma
We describe recent developments of the "magnetic scenario" of sQGP. We show
that at there is a dense plasma of monopoles, capable of
supporting metastable flux tubes. Their existence allows to quantitatively
explained the non-trivial -dependence of the static potential
energy calculated on the lattice. By molecular dynamics simulation we derived
transport properties (shear viscosity and diffusion constant) and showed that
the best liquid is given by most symmetric plasma, with 50%-50% of electric and
magnetic charges. The results are close to those of the ``perfect liquid''
observed at RHIC.Comment: Contribution to the 20th International Conference on Nucleus Nucleus
Collisions (Quark Matter 2008
Interaction of cosmic background neutrinos with matter of periodic structure
We study coherent interaction of cosmic background neutrinos(CBNs) with
matter of periodic structure. The mixing and small masses of neutrinos
discovered in neutrino oscillation experiments indicate that CBNs which have
very low energy today should be in mass states and can transform from one mass
state to another in interaction with electrons in matter. We show that in a
coherent scattering process a periodic matter structure designed to match the
scale of the mass square difference of neutrinos can enhance the conversion of
CBNs from one mass state to another. Energy of CBNs can be released in this
scattering process and momentum transfer from CBNs to electrons in target
matter can be obtained.Comment: 6 pages, 5 figures, publication versio
No UV/IR Mixing in Unitary Space-Time Noncommutative Field Theory
In this article we calculate several divergent amplitudes in phi^4-theory on
non-commutative space-time in the framework of Interaction Point Time Ordered
Perturbation Theory (IPTOPT), continuing work done in hep-th/0209253. On the
ground of these results we find corresponding Feynman rules which allow for a
much easier diagrammatic calculation of amplitudes. The most important feature
of the present theory is the lack of the UV/IR mixing problem in all amplitudes
calculated so far. Although we are not yet able to give a rigorous proof, we
provide a strong argument for this result to hold in general. Together with the
found Feynman rules this opens promising vistas towards the systematic
renormalization of non-commutative field theories.Comment: 23 pages, uses package feynmf, v2: typos, added reference, minor
improvement
What do lattice baryonic susceptibilities tell us about quarks, diquarks and baryons at ?
Lattice data on QCD thermodynamics, especially recent study of high order
susceptibilities by UK-Bielefeld collaboration, have provided valuable
information about matter properties around and above the critical temperature
. In this work we tried to understand what physical picture would explain
these numerical data. We found two scenarios which will do it: (i) a quark
quasiparticle gas, with the effective mass which is strongly near
the phase boundary into the QGP phase; or (ii) a picture including baryons at
, with the mass rapidly across the phase boundary toward
QGP. We further provide several arguments in favor of the latter scenario, one
of which is a natural continuity with the baryon gas picture at .Comment: 11 pages, 7 figures. One reference as well as few comments were adde
Angular Dependence of Jet Quenching Indicates Its Strong Enhancement Near the QCD Phase Transition
We study dependence of jet quenching on matter density, using "tomography" of
the fireball provided by RHIC data on azimuthal anisotropy of high
hadron yield at different centralities. Slicing the fireball into shells with
constant (entropy) density, we derive a "layer-wise geometrical limit"
which is indeed above the data . Interestingly, the
limit is reached only if quenching is dominated by shells with the entropy
density exactly in the near- region. We show two models that
simultaneously describe the high and data and conclude
that such a description can be achieved only if the jet quenching is few times
stronger in the near- region relative to QGP at . One possible
reason for that may be recent indications that the near- region is a
magnetic plasma of relatively light color-magnetic monopoles.Comment: 4 pages, 4 figures. Final version published as PRL102,202302(2009
Constraints on Neutrino Velocities Revisited
With a minimally modified dispersion relation for neutrinos, we reconsider
the constraints on superluminal neutrino velocities from bremsstrahlung effects
in the laboratory frame. Employing both the direct calculation approach and the
virtual Z-boson approach, we obtain the generic decay width and energy loss
rate of a superluminal neutrino with general energy. The Cohen-Glashow's
analytical results for neutrinos with a relatively low energy are confirmed in
both approaches. We employ the survival probability instead of the terminal
energy to assess whether a neutrino with a given energy is observable or not in
the OPERA experiment. Moreover, using our general results we perform
systematical analyses on the constraints arising from the Super-Kamiokande and
IceCube experiments.Comment: RevTex4, 14 pages, 5 figures, minor corrections, version to appear in
Phys. Rev.
Limiting efficiencies of solar energy conversion and photo-detection via internal emission of hot electrons and hot holes in gold
We evaluate the limiting efficiency of full and partial solar spectrum
harvesting via the process of internal photoemission in Au-semiconductor
Schottky junctions. Our results based on the ab initio calculations of the
electron density of states (e-DOS) reveal that the limiting efficiency of the
full-spectrum Au converter based on hot electron injection is below 4%. This
value is even lower than previously established limit based on the parabolic
approximation of the Au electron energy bands. However, we predict limiting
efficiency exceeding 10% for the hot holes collection through the Schottky
junction between Au and p-type semiconductor. Furthermore, we demonstrate that
such converters have more potential if used as a part of the hybrid system for
harvesting high- and low-energy photons of the solar spectrum.Comment: Proc. SPIE 9608, Infrared Remote Sensing and Instrumentation XXIII,
960816 (September 1, 2015) 7 pages, 4 figure
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