174 research outputs found
Polycyclic aromatic hydrocarbons in the surface soils from outskirts of Beijing, China
Search for the Chiral Magnetic Effect in Au+Au collisions at GeV with the STAR forward Event Plane Detectors
A decisive experimental test of the Chiral Magnetic Effect (CME) is
considered one of the major scientific goals at the Relativistic Heavy-Ion
Collider (RHIC) towards understanding the nontrivial topological fluctuations
of the Quantum Chromodynamics vacuum. In heavy-ion collisions, the CME is
expected to result in a charge separation phenomenon across the reaction plane,
whose strength could be strongly energy dependent. The previous CME searches
have been focused on top RHIC energy collisions. In this Letter, we present a
low energy search for the CME in Au+Au collisions at
GeV. We measure elliptic flow scaled charge-dependent correlators relative to
the event planes that are defined at both mid-rapidity and at
forward rapidity . We compare the results based on the
directed flow plane () at forward rapidity and the elliptic flow plane
() at both central and forward rapidity. The CME scenario is expected
to result in a larger correlation relative to than to , while
a flow driven background scenario would lead to a consistent result for both
event planes[1,2]. In 10-50\% centrality, results using three different event
planes are found to be consistent within experimental uncertainties, suggesting
a flow driven background scenario dominating the measurement. We obtain an
upper limit on the deviation from a flow driven background scenario at the 95\%
confidence level. This work opens up a possible road map towards future CME
search with the high statistics data from the RHIC Beam Energy Scan Phase-II.Comment: main: 8 pages, 5 figures; supplementary material: 2 pages, 1 figur
Image processing and geometric parameters extracted from sliced image of porous biomaterial
Homogeneous switching mechanism in pure polyvinylidene fluoride ultrathin films
International audiencePolarization switching kinetics is one of the key issues for future development of nanoelectronic devices based on ferroelectrics. Up to now, such kinetics still remains poorly studied despite its crucial impact on the device performances. Here, the switching mechanism in 11-nm-thick ferroelectric films of pure homopolymer of polyvinylidene fluoride is investigated. While the usual mechanism involves nucleation and growth of domains, a homogeneous ferroelectric switching is evidenced in such ultrathin films. Indeed, the dependence of the switching rate on applied voltage reveals a critical behavior with the existence of a true threshold field (of ∼0.26 GV/m) which is required to overcome the energy barrier to reverse the whole polarization homogeneously as suggested by Landau-Ginzburg mean-field theory. Such finding not only supports few previous works but also raises the question on the general aspect of such homogeneous mechanism that might exist in any other nanoscale ferroelectric materials
Application of the Chaos Theory in the Analysis of EMG on Patients with Facial Paralysis
Recombinant human interleukin-11 for treatment of chemotherapy-induced thrombocytopenia in patients with gastrointestinal cancer
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