7,487 research outputs found
QCD Collisional Energy Loss in an Increasingly Interacting Quark Gluon Plasma
The discovery of the jet quenching in central Au + Au collisions at the
Relativistic Heavy-ion Collider (RHIC) at Brookhaven National Laboratory has
provided clear evidence for the formation of strongly interacting dense matter.
It has been predicted to occur due to the energy loss of high energy partons
that propagate through the quark gluon plasma. In this paper we investigate the
dependence of the parton energy loss due to elastic scatterings in a parton
plasma on the value of the strong coupling and its running with the evolution
of the system. We analyze different prescriptions for the QCD coupling and
calculate the energy and length dependence of the fractional energy loss.
Moreover, the partonic quenching factor for light and heavy quarks is
estimated. We found that the predicted enhancement of the heavy to light
hadrons () ratio is strongly dependent on the running of the QCD
coupling constant.Comment: 16 pages, 8 figures. Version to be published in the International
Journal of Modern Physics
On the energy dependence of the D^+/D^- production asymmetry
In this paper we discuss the origin of the asymmetry present in D meson
production and its energy dependence. In particular, we have applied the meson
cloud model to calculate the asymmetries in D^-/D^+ meson production in high
energy p-p collisions and find a good agreement with recent LHCb data. Although
small, this non-vanishing asymmetry may shed light on the role played by the
charm meson cloud of the proton.Comment: 8 pages, 8 figures. arXiv admin note: text overlap with
arXiv:hep-ph/000927
Coulomb corrections to inclusive cross sections at the future Electron - Ion Collider
The experimental results of the future electron -- ion () collider are
expected to constrain the dynamics of the strong interactions at small values
of the Bjorken -- variable and large nuclei. Recently it has been suggested
that Coulomb corrections can be important in inclusive and diffractive
interactions. In this paper we present a detailed investigation of the impact
of the Coulomb corrections to some of the observables that will be measured in
the future collider. In particular, we estimate the magnitude of these
corrections for the charm and longitudinal cross sections in inclusive and
diffractive interactions. Our results demonstrate that the Coulomb corrections
for these observables are negligible, which implies that they can be used to
probe the QCD dynamics.Comment: 9 pages, 6 figures. Improved version to be published in Physical
Review
MGBG in Combined Anticancer Chemotherapy
This paper is intended to provide a foundation for further discussion and debate at the plenary panel on “Civility and Academic Freedom” at the National Center’s annual conference on April 20, 2015. The discussion, below, sets forth a structure for evaluating university policies seeking promote “civility” in faculty and student discourse. In particular, this paper evaluates the asserted justifications for civility-related policies and their implications for academic freedom. The paper provides, as well, a list of AAUP materials useful for considering the academic freedom implications of civility-related policies in universities
Inclusive gauge boson production in the color dipole formalism
The inclusive production of the gauge bosons and is studied
within the color dipole formalism. Gluon saturation effects associated to
non-linear corrections to the QCD dynamics, which are expected to contribute at
high energies, are naturally included in such formalism. We estimate the
contribution of these effects at LHC energies and compare our results with the
next-to-next-to-leading order collinear predictions. A comparison with the
current experimental data is performed and predictions for higher energies are
presented.Comment: 12 pages, 6 figures, 2 tables. Version to be published in Physical
Review
Environmental assessment of humic acid coated magnetic materials used as catalyst in photo-fenton processes
Persistent organic pollutants have been increasingly detected in natural waters, and this represents a real challenge to the quality of this resource. To remove these species, advanced treatment technologies are required. Among these technologies, Fenton-like and photo-Fenton-like processes have been investigated for the removal of pollutants from water. Delicate aspects of photo-Fenton processes are that light-driven processes are energy intensive and require a fair amount of chemical inputs, which strongly affects their overall environmental burdens. At present, aside from determining the efficiency of the processes to remove pollutants of a particular technology, it becomes fundamental to assess also the environmental sustainability of the overall process. In this work, the methodology of the life cycle assessment (LCA) was applied to identify the hotspots of using magnetite particles covered with humic acid (Fe3O4/HA) as a heterogeneous photo-Fenton catalyst for water remediation. The sustainability of the overall process was considered, and a comparative LCA study was performed between H2O2 and persulfate activation at different pH. The addition of humic substances to the particles allows the effectiveness of the catalyst to improve without increasing the environmental impacts; these processes are strongly correlated with energy consumption and therefore with the efficiency of the process. For this reason, working at acidic pH allows us to contain the impacts
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