Search results for "Collision"
showing 10 items of 908 documents
ATOM-WALL COLLISIONS INFLUENCE ON DARKLINE ATOMIC RESONANCES IN SUBMICRON THIN VAPOUR CELLS.
2010
Recently it was demonstrated that miniaturization of alkali cells, i.e. the use of an extremely thin cell (ETC) for the applications using the electromagnetically induced transparency (EIT) effect, despite to intuitive expectation, does not cause a strong broadening of the dark-line (DL) linewidth. Here we present the conditions when a strong broadening of DL linewidth (more than by 10 times) can be easily observed due to atom-wall collisions influence and this could be a convenient and robust tool for atomwall (i.e. ETC's window material/temperature) collisions study. We present experimental and theoretical results on EIT realized in a Λ- system of 85Rb, D2 line, 5S-5P-5S for a Rb vapour c…
Molecular alignment echoes probe collision-induced rotational-speed changes
2020
International audience; We show that the decays with pressure of the rotational alignment echoes induced in N 2 O-He gas mixtures by two ultrashort laser pulses with various delays show detailed information about collision-induced changes of the rotational speed of the molecules. Measurements and classical calculations consistently demonstrate that collisions reduce the echo amplitude all the more efficiently when the echo appears late. We quantitatively explain this behavior by the filamentation of the classical rotational phase space induced by the first pulse and the narrowing of the filaments with time. The above mentioned variation of the echo decay then reflects the ability of collisi…
Etude des effets collisionnels dans les molécules tétraédriques. Applications au méthane perturbé par l'argon
1996
This thesis is devoted to the study of relaxational and collisional line-broadening processes in the first vibrational polyads of tetrahedral molecules. In a first part, the particular internal dynamics of such molecules is discussed. The second chapter reviews the literature on phenomena induced by intermolecular interactions involving this type of molecules. More theoretical aspects are developed in the second part. The so-called tetrahedral tensorial formalism adapted to the construction of Hamiltonians and transition moments of tetrahedral molecules is described. Main features of the infrared line-shapes theories and of semi-classical line-broadening and line-shifting calculations are a…
Visual and acoustic techniques for motorcycle collision warning system with EEG validation
2018
In many countries, motorcyclist fatality rate is much higher than that of other vehicle drivers. Among many other factors, motorcycle rear-end collisions are also contributing to these biker fatalities. Collision detection systems can be used to minimize these fatalities. However, most of the existing collision detection systems do not identify the type of potential hazard faced by motorcyclists. Every collision warning system used a distinctive collision detection technique, which limits its performance and makes it imperative to study its effectiveness. Unfortunately, no such work has been reported in that particular domain for motorcyclists. Therefore, it is important to study the physio…
Geochemistry, Sr–Nd–Pb isotopes and geochronology of amphibole- and mica-bearing lamprophyres in northwestern Iran: Implications for mantle wedge het…
2015
Highlights • Northwestern Iranian lamprophyres have alkaline and calc-alkaline nature. • Studied lamprophyres are emplaced during Late Cretaceous to Late Miocene time. • Lamprophyres originated from different metasomatised lithospheric mantle. Abstract Lamprophyres of different age showing distinctive mineralogy, geochemistry and isotopic ratios are exposed in northwestern Iran. They can be divided into Late Cretaceous sannaite, Late Oligocene-Early Miocene camptonite (amphibole-bearing) and Late Miocene minette (mica-bearing) and spessartite (amphibole-bearing) lamprophyres. Sannaites have high-Ti amphibole along with high-Ti and Al clinopyroxene, and they are characterised by homogeneous …
Measurement of the higher-order anisotropic flow coefficients for identified hadrons in Au + Au collisions at √sNN = 200 GeV
2016
Measurements of the anisotropic flow coefficients v2{2}, v3{3}, v4{4}, and v4{2} for identified particles (π±, K±, and p + p¯) at midrapidity, obtained relative to the event planes m at forward rapidities in Au + Au collisions at √sNN = 200 GeV, are presented as a function of collision centrality and particle transverse momenta pT . The vn coefficients show characteristic patterns consistent with hydrodynamical expansion of the matter produced in the collisions. For each harmonic n, a modified valence quark-number Nq scaling [plotting vn{m}/(Nq ) n/2 versus transverse kinetic energies (KET )/Nq ] is observed to yield a single curve for all the measured particle species for a broad range of …
Observation of Higgs boson production in association with a top quark pair at the LHC with the ATLAS detector
2018
Physics letters / B 784, 173 - 191 (2018). doi:10.1016/j.physletb.2018.07.035
Kaon-proton strong interaction at low relative momentum via femtoscopy in Pb-Pb collisions at the LHC
2021
Physics letters / B 822, 136708 (2021). doi:10.1016/j.physletb.2021.136708
Measurement of light-by-light scattering and search for axion-like particles with 2.2 nb−1 of Pb+Pb data with the ATLAS detector
2021
We thank CERN for the very successful operation of the LHC, as well as the support staff from our institutions without whom ATLAS could not be operated efficiently. We acknowledge the support of ANPCyT, Argentina; YerPhI, Armenia; ARC, Australia; BMWFW and FWF, Austria; ANAS, Azerbaijan; SSTC, Belarus; CNPq and FAPESP, Brazil; NSERC, NRC and CFI, Canada; CERN; ANID, Chile; CAS, MOST and NSFC, China; COLCIENCIAS, Colombia; MSMT CR, MPO CR and VSC CR, Czech Republic; DNRF and DNSRC, Denmark; IN2P3-CNRS and CEA-DRF/IRFU, France; SRNSFG, Georgia; BMBF, HGF and MPG, Germany; GSRT, Greece; RGC and Hong Kong SAR, China; ISF and Benoziyo Center, Israel; INFN, Italy; MEXT and JSPS, Japan; CNRST, Mor…
Measurement of higher cumulants of net-charge multiplicity distributions in Au+Au collisions at √sNN = 7.7-200 GeV
2016
We report the measurement of cumulants (Cn,n = 1,...,4) of the net-charge distributions measured within pseudorapidity (|η| < 0.35) in Au + Au collisions at √sNN = 7.7–200 GeV with the PHENIX experiment at the Relativistic Heavy Ion Collider. The ratios of cumulants (e.g., C1/C2, C3/C1) of the net-charge distributions, which can be related to volume independent susceptibility ratios, are studied as a function of centrality and energy. These quantities are important to understand the quantum-chromodynamics phase diagram and possible existence of a critical end point. The measured values are very well described by expectation from negative binomial distributions. We do not observe any nonmono…