7,836 research outputs found
Detection of hidden structures on all scales in amorphous materials and complex physical systems: basic notions and applications to networks, lattice systems, and glasses
Recent decades have seen the discovery of numerous complex materials. At the
root of the complexity underlying many of these materials lies a large number
of possible contending atomic- and larger-scale configurations and the
intricate correlations between their constituents. For a detailed
understanding, there is a need for tools that enable the detection of pertinent
structures on all spatial and temporal scales. Towards this end, we suggest a
new method by invoking ideas from network analysis and information theory. Our
method efficiently identifies basic unit cells and topological defects in
systems with low disorder and may analyze general amorphous structures to
identify candidate natural structures where a clear definition of order is
lacking. This general unbiased detection of physical structure does not require
a guess as to which of the system properties should be deemed as important and
may constitute a natural point of departure for further analysis. The method
applies to both static and dynamic systems.Comment: (23 pages, 9 figures
Neutrino Emissivity of Dense Stars
The neutrino emissivity of compact stars is investigated in this work. We
consider stars consisting of nuclear as well as quark matter for this purpose.
Different models are used to calculate the composition of nuclear and quark
matter and the neutrino emissivity. Depending on the model under consideration,
the neutrino emissivity of nuclear as well as quark matter varies over a wide
range. We find that for nuclear matter, the direct URCA processes are allowed
for most of the relativistic models without and with strange baryons, whereas
for the nonrelativistic models this shows a strong dependence on the type of
nuclear interaction employed. When the direct URCA processes are allowed, the
neutrino emissivity of hadronic matter is larger than that of the quark matter
by several orders of magnitude. We also find that the neutrino emissivity
departs from behavior when the temperature is larger than the difference
in the Fermi momenta of the particles, participating in the neutrino-producing
reactions.Comment: Latex file. 5 figures available on request. accepted in Int. J. Mod.
Phys.
Characterization of Jets in Relativistic Heavy Ion Collisions
Jet quenching is considered to be one of the signatures of the formation of
quark gluon plasma. In order to investigate the jet quenching, it is necessary
to detect jets produced in relativistic heavy ion collisions, determine their
properties and compare those with the jets one obtains in hadron-hadron or
collisions. In this work, we propose that calculation of flow
parameters may be used to detect and characterize jets in relativistic heavy
ion collisions.Comment: 18 pages, 4 figures, more discussions are added, to be published in
Phys. Rev.
Azimuthal correlations of D-mesons in + and +Pb collisions at LHC energies
We study the correlations of D mesons produced in + and +Pb
collisions. These are found to be sensitive to the effects of the cold nuclear
medium and the transverse momentum () regions we are looking into. In
order to put this on a quantitative footing, as a first step we analyse the
azimuthal correlations of D meson-charged hadron(Dh), and then predict the same
for D meson -anti D meson () pairs in + and +Pb
collisions with strong coupling at leading order ()
and next to leading order () which includes space-time
evolution (in both systems), as well cold nuclear matter effects (in +Pb).
This also sets the stage and baseline for the identification and study of
medium modification of azimuthal correlations in relativistic collision of
heavy nuclei at the Large Hadron Collider.Comment: 12 pages, 4 figure
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