2,609 research outputs found
Heavy Flavor Probes of Quark Matter
A brief survey of the role of heavy flavors as a probe of the state of matter
produced by high energy heavy ion collisions is presented. Specific examples
include energy loss, initial state gluon saturation, thermalization and flow.
The formation of quarkonium bound states from interactions in which multiple
heavy quark-antiquark pairs are initially produced is examined in general.
Results from statistical hadronization and kinetic models are summarized. New
predictions from the kinetic model for J/Psi at RHIC are presented.Comment: Based on invited plenary talk at Strange Quark Matter 2004, Cape
Town, South Africa, September 15-20, 2004, references completed, published in
J. Phys. G: Nucl. Part. Phys. 31 (2005) S641-S64
Correlations of Heavy Quarks Produced at Large Hadron Collider
We study the correlations of heavy quarks produced in relativistic heavy ion
collisions and find them to be quite sensitive to the effects of the medium and
the production mechanisms. In order to put this on a quantitative footing, as a
first step, we analyze the azimuthal, transverse momentum, and rapidity
correlations of heavy quark-anti quark () pairs in
collisions at (). This sets the stage for the
identification and study of medium modification of similar correlations in
relativistic collision of heavy nuclei at the Large Hadron Collider. Next we
study the additional production of charm quarks in heavy ion collisions due to
multiple scatterings, {\it viz.}, jet-jet collisions, jet-thermal collisions,
and thermal interactions. We find that these give rise to azimuthal
correlations which are quite different from those arising from prompt initial
production at leading order and at next to leading order.Comment: 26 pages, 15 figures. Three new figures added, comparison to
experimental data included, abstract and discussion expande
Characterization of surface-states in a hollow core photonic crystal fiber
FAPESP - FUNDAĂĂO DE AMPARO Ă PESQUISA DO ESTADO DE SĂO PAULOCAPES - COORDENAĂĂO DE APERFEIĂOAMENTO DE PESSOAL E NĂVEL SUPERIORCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTĂFICO E TECNOLĂGICOSurface or edge states represent an important class of modes in various photonic crystal systems such as in dielectric topological insulators and in photonic crystal fibers. In the later, strong attenuation peaks in the transmission spectrum are attributed to coupling between surface and core-guided modes. Here, we explore a modified implementation of the spatial and spectral interference method to experimentally characterize surface modes in photonic crystal fibers. Using an external reference and a non-uniform Fourier transform windowing, the obtained spectrogram allows clear observation of anti-crossing behavior at wavelengths in which surface and core modes are strongly coupled. We also detect surface modes with different spatial symmetries, and give insight into mode families couple to the fundamental or high-order core modes, as well as the existence of uncoupled surface modes.26253255432564FAPESP - FUNDAĂĂO DE AMPARO Ă PESQUISA DO ESTADO DE SĂO PAULOCAPES - COORDENAĂĂO DE APERFEIĂOAMENTO DE PESSOAL E NĂVEL SUPERIORCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTĂFICO E TECNOLĂGICOFAPESP - FUNDAĂĂO DE AMPARO Ă PESQUISA DO ESTADO DE SĂO PAULOCAPES - COORDENAĂĂO DE APERFEIĂOAMENTO DE PESSOAL E NĂVEL SUPERIORCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTĂFICO E TECNOLĂGICO2013/20180-32015/04113-008/57857-2Sem informação574017/2008-
Cumulative radiation exposure during thoracic endovascular aneurysm repair and subsequent follow-up
n/
Hard probes in heavy ion collisions at the LHC: heavy flavour physics
We present the results from the heavy quarks and quarkonia working group.
This report gives benchmark heavy quark and quarkonium cross sections for
and collisions at the LHC against which the rates can be compared in
the study of the quark-gluon plasma. We also provide an assessment of the
theoretical uncertainties in these benchmarks. We then discuss some of the cold
matter effects on quarkonia production, including nuclear absorption,
scattering by produced hadrons, and energy loss in the medium. Hot matter
effects that could reduce the observed quarkonium rates such as color screening
and thermal activation are then discussed. Possible quarkonium enhancement
through coalescence of uncorrelated heavy quarks and antiquarks is also
described. Finally, we discuss the capabilities of the LHC detectors to measure
heavy quarks and quarkonia as well as the Monte Carlo generators used in the
data analysis.Comment: 126 pages Latex; 96 figures included. Subgroup report, to appear in
the CERN Yellow Book of the workshop: Hard Probes in Heavy Ion Collisions at
the LHC. See also http://a.home.cern.ch/f/frixione/www/hvq.html for a version
with better quality for a few plot
Photon tagged correlations in heavy ion collisions
A detailed study of various two-particle correlation functions involving
photons and neutral pions is presented in proton-proton and lead-lead
collisions at the LHC energy. The aim is to use these correlation functions to
quantify the effect of the medium (in lead-lead collisions) on the jet decay
properties. The calculations are carried out at the leading order in QCD but
the next-to-leading order corrections are also discussed. The competition
between different production mechanisms makes the connection between the jet
energy loss spectrum and the gamma-pi correlations somewhat indirect while the
gamma-gamma correlations have a clearer relation to the jet fragmentation
properties.Comment: 32 pages, 19 figures. Minor changes, published versio
Future Experiments in Relativistic Heavy Ion Collisions
The measurements at RHIC have revealed a new state of matter, which needs to
be further characterized in order to better understand its implications for the
early evolution of the universe and QCD. I will show that, in the near future,
complementary key measurements can be performed at RHIC, LHC, and FAIR. I will
focus on results than can be obtained using identified particles, a probe which
has been the basis for this conference over the past three decades. The
sophisticated detectors, built and planned, for all three accelerator
facilities enable us to measure leptons, photons, muons as well as hadrons and
resonances of all flavors almost equally well, which makes these experiments
unprecedented precision tools for the comprehensive understanding of the
physics of the early universe.Comment: 10 pages, 4 figures, Proceedings for Summary Talk at SQM 2007,
Levoca, Slovakia, June 24-29, 200
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