17,061 research outputs found
Hadronization via Coalescence
We review the quark coalescence model for hadronization in relativistic heavy
ion collisions and show how it can explain the observed large baryon to meson
ratio at intermediate transverse momentum and scaling of the elliptic flows of
identified hadrons. We also show its predictions on higher-order anisotropic
flows and discuss how quark coalescence applied to open- and hidden-charm
mesons can give insight to charm quark interactions in the quark-gluon plasma
and production in heavy ion collisions.Comment: 6 pages, 4 figures, Proceedings of 20th Winter Workshop on Nuclear
Dynamics, Trelawny Beach, Jamaica, March 15--20, 200
Safe discontinuation of nilotinib in a patient with chronic myeloid leukemia: a case report
Case presentation. We report the case of a 64-year-old Caucasian man diagnosed with chronic-phase chronic myeloid leukemia in April 2005. After 4 years of treatment with imatinib, he became intolerant to the drug and was switched to nilotinib. Two years later, he decided to stop nilotinib. Undetectable molecular response persisted for 30 months after discontinuation of the drug.
Introduction. Although there is a considerable amount of data in the literature on safe discontinuation of first-generation tyrosine kinase inhibitor therapy in patients with chronic myeloid leukemia, little is known about discontinuation of second-generation tyrosine kinase inhibitor therapy. Most previous studies have been focused on dasatinib, and the few cases of nilotinib withdrawal that have been reported had a median follow-up of 12 months. To the best of our knowledge, the present report is the first to describe nilotinib withdrawal with 30 months of follow-up.
Conclusion: Our present case suggests that nilotinib withdrawal is safe for patients with chronic myeloid leukemia who achieve a stable undetectable molecular response. Our patient was homozygous for killer immunoglobulin-like receptor haplotype A, previously reported to be a promising immunogenetic marker for undetectable molecular response. We recommend additional studies to investigate patient immunogenetic profiles and their potential role in complete response to therap
Transport properties of isospin effective mass splitting
We investigate in detail the momentum dependence () of the effective in
medium Nucleon-Nucleon () interaction in the isovector channel. We focus
the discussion on transport properties of the expected neutron-proton ()
effective mass splitting at high isospin density. We look at observable effects
from collective flows in Heavy Ion Collisions () of charge asymmetric
nuclei at intermediate energies. Using microscopic kinetic equation simulations
nucleon transverse and elliptic collective flows in collisions are
evaluated. In spite of the reduced charge asymmetry of the interacting system
interesting effects are revealed. Good observables, particularly
sensitive to the -mass splitting, appear to be the differences between
neutron and proton flows. The importance of more exclusive measurements, with a
selection of different bins of the transverse momenta () of the emitted
particles, is stressed. In more inclusive data a compensation can be expected
from different -contributions, due to the microscopic
structure of the nuclear mean field in asymmetric matter.Comment: 18 pages, 11 figure
Impact of temperature dependence of the energy loss on jet quenching observables
The quenching of jets (particles with ) in
ultra-relativistic heavy-ion collisions has been one of the main prediction and
discovery at RHIC. We have studied, by a simple jet quenching modeling, the
correlation between different observables like the nuclear modification factor
\Rapt, the elliptic flow and the ratio of quark to gluon suppression
. We show that the relation among these
observables is strongly affected by the temperature dependence of the energy
loss. In particular the large and and the nearly equal \Rapt of quarks
and gluons can be accounted for only if the energy loss occurs mainly around
the temperature and the flavour conversion is significant.Finally we
point out that the efficency in the conversion of the space eccentricity into
the momentum one () results to be quite smaller respect to the one coming
from elastic scatterings in a fluid with a viscosity to entropy density ratio
.Comment: 7 pages, 8 figures, Workshop WISH 201
Scalings of Elliptic Flow for a Fluid at Finite Shear Viscosity
Within a parton cascade approach we investigate the scaling of the
differential elliptic flow with eccentricity and system
size and its sensitivity to finite shear viscosity. We present calculations for
shear viscosity to entropy density ratio in the range from up
to , finding that the saturation value varies by about a factor 2.
Scaling of is seen also for finite which
indicates that it does not prove a perfect hydrodynamical behavior, but is
compatible with a plasma at finite . Introducing a suitable freeze-out
condition, we see a significant reduction of especially at
intermediate and for more peripheral collisions. This causes a breaking
of the scaling for both and the averaged , while keeping
the scaling of v_2(p_T)/\la v_2\ra. This is in better agreement with the
experimental observations and shows as a first indication that the
should be significantly lower than the pQCD estimates. We finally point out the
necessity to include the hadronization via coalescence for a definite
evaluation of from intermediate data.Comment: 5 pages, 5 figures. Two points in fig.4 has been change
Probing the Nuclear Symmetry Energy with Heavy Ion Collisions
Heavy Ion Collisions (HIC) represent a unique tool to probe the in-medium
nuclear interaction in regions away from saturation. In this report we present
a selection of new reaction observables in dissipative collisions particularly
sensitive to the symmetry term of the nuclear Equation of State (). We
will first discuss the Isospin Equilibration Dynamics. At low energies this
manifests via the recently observed Dynamical Dipole Radiation, due to a
collective neutron-proton oscillation with the symmetry term acting as a
restoring force. At higher beam energies Iso-EoS effects will be seen in an
Isospin Diffusion mechanism, via Imbalance Ratio Measurements, in particular
from correlations to the total kinetic energy loss. For fragmentation reactions
in central events we suggest to look at the coupling between isospin
distillation and radial flow. In Neck Fragmentation reactions important Iso-EoS
information can be obtained from fragment isospin content, velocity and
alignement correlations. The high density symmetry term can be probed from
isospin effects on heavy ion reactions at relativistic energies (few AGeV
range), in particular for high transverse momentum selections of the reaction
products. Rather isospin sensitive observables are proposed from
nucleon/cluster emissions, collective flows and meson production. The
possibility to shed light on the controversial neutron/proton effective mass
splitting in asymmetric matter is also suggested.
A large symmetry repulsion at high baryon density will also lead to an
"earlier" hadron-deconfinement transition in n-rich matter. The binodal
transition line of the (T,\rho_B) diagram is lowered to a region accessible
through heavy ion collisions in the energy range of the new planned facilities,
e.g. the FAIR/NICA projects. Some observable effects of the formation of a
Mixed Phase are suggested, in particular a Neutron Trapping mechanism. The
dependence of the results on a suitable treatment of the isovector part of the
interaction in effective QCD Lagrangian approaches is critically discussed. We
stress the interest of this study in nuclear astrophysics, in particular for
supernovae explosions and neutron star structure, where the knowledge of the
Iso-EoS is important at low as well as at high baryon density.Comment: 52 pages, 28 figures, topical review submitted to J. Phys. G: Nucl.
Phys (IOP Latex
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