Search results for "Azimuth"
showing 10 items of 194 documents
Tau-spin correlations at the z-peak: aplanarities of the decay products
1991
8 páginas, 3 figuras, 1 tabla.-- CERN-TH-5932-90 ; FTUV-90-26.
Assessment of the out-plane and in-plane ordering of high quality ZnO nanorods by X-ray multiple diffraction
2013
Abstract ZnO nanorods grown on buffered and non buffered sapphire substrates have been investigated by X-ray multiple diffraction using Renninger scans of the ZnO(0001) and ZnO(0003) forbidden reflections. In this technique the diffracted X-ray beam is simultaneously diffracted by several sets of planes, providing information on the broadening in different directions, as well as from nanorods, and from the layer on which they grow. The intensities and angular widths of peaks obtained by azimuthal and omega scans have been analyzed, making a direct comparison with conventional measurements of the full width at half-maximum of symmetric and asymmetric reflections. The analysis leads to establ…
Treatment of grazing-incidence small-angle X-ray scattering data taken above the critical angle
2001
The equations taking into account refraction at the sample surface in grazing-incidence small-angle X-ray scattering (GISAXS) when the angle between the incoming beam and the sample surface is slightly larger than the critical angle are derived and discussed. It is demonstrated that the refraction of both the incoming and the scattered beam at the sample surface affects the GISAXS pattern and that, when a planar bidimensional detector perpendicular to the incoming beam is used, the effect depends on the azimuthal detector angle. The smearing of the pattern depending on the size of the illuminated sample area in grazing incidence is estimated by simulations with Cauchy functions of different…
First Measurement of Transverse-Spin-Dependent Azimuthal Asymmetries in the Drell-Yan Process
2017
The first measurement of transverse-spin-dependent azimuthal asymmetries in the pion-induced Drell-Yan (DY) process is reported. We use the CERN SPS 190 GeV/$c$, $\pi^{-}$ beam and a transversely polarized ammonia target. Three azimuthal asymmetries giving access to different transverse-momentum-dependent (TMD) parton distribution functions (PDFs) are extracted using dimuon events with invariant mass between 4.3 GeV/$c^2$ and 8.5 GeV/$c^2$. The observed sign of the Sivers asymmetry is found to be consistent with the fundamental prediction of Quantum Chromodynamics (QCD) that the Sivers TMD PDFs extracted from DY have a sign opposite to the one extracted from semi-inclusive deep-inelastic sc…
Sivers asymmetry extracted in SIDIS at the hard scales of the Drell-Yan process at COMPASS
2017
Proton transverse-spin azimuthal asymmetries are extracted from the COMPASS 2010 semi-inclusive hadron measurements in deep inelastic muon-nucleon scattering in those four regions of the photon virtuality $Q^2$, which correspond to the four regions of the di-muon mass $\sqrt{Q^2}$ used in the ongoing analysis of the COMPASS Drell-Yan measurements. This allows for a future direct comparison of the nucleon transverse-momentum-dependent parton distribution functions extracted from these two alternative measurements. Various two-dimensional kinematic dependences are presented for the azimuthal asymmetries induced by the Sivers transverse-momentum-dependent parton distribution function. The inte…
Evaluation of the coupled high-resolution atmospheric chemistry model system MECO(n) using in situ and MAX-DOAS NO<sub>2</sub&am…
2021
Abstract. We present high spatial resolution (up to 2.2×2.2 km2) simulations focussed over south-west Germany using the online coupled regional atmospheric chemistry model system MECO(n) (MESSy-fied ECHAM and COSMO models nested n times). Numerical simulation of nitrogen dioxide (NO2) surface volume mixing ratios (VMRs) are compared to in situ measurements from a network with 193 locations including background, traffic-adjacent and industrial stations to investigate the model's performance in simulating the spatial and temporal variability of short-lived chemical species. We show that the use of a high-resolution and up-to-date emission inventory is crucial for reproducing the spatial varia…
Electromagnetic Scattering by a Strip Grating with Plane-Wave Three-Dimensional Oblique Incidence by Means of Decomposition into E-Type and H-Type Mo…
1993
A numerical algorithm to analyze the plane-wave three-dimensional oblique incidence on a strip grating is presented. Electromagnetic field is decomposed into vector Floquet harmonics of the E-type and H-type modes. To impose boundary conditions on the incident, reflected and transmitted waves, two integral equations of Fredholm of first kind are obtained. These equations are solved numerically with the standard Galerkin procedure, and the convergence of the algorithm is examined numerically. Since the superficial current near the edges of a conducting strip have been taken into account, the computational algorithm shows a fast convergence. Results are compared with other numerical results a…
Head-group variations and monolayer structures of diol derivatives
2007
Monolayers of 5 chemically modified diols varying the headgroup (nonadecane-1,2-diol (C1), hexadecyl-propane-1,3-diol (C2), hexadecyl-oxy-propane-1,2-diol (C3), hexadecyl-oxy-butane-1,2-diol (C4), hexadecanoyl-oxy-propane-1,2-diol (C5)) have been investigated by grazing incidence x-ray diffraction at 20°C and at different lateral pressures. C1 and C5 exhibit a centred-rectangular lattice with NN (nearest neighbour) tilt and NN distortion directions. In the case of C1 on increasing the lateral pressure the distortion changes to NNN (next-nearest neighbour direction) without a change in tilt direction (NN). This behaviour could not be observed for the other compounds. C3 and C4 display a phas…
"Figure 3.1" of "Measurements of Higher-Order Flow Harmonics in Au+Au Collisions at sqrt(s_NN) = 200 GeV"
2020
Charged hadron azimuthal anisotropy $v_4$ vs centrality in Au+Au collisions at 200 GeV. The corresponding Npart value to each centrality is shown in Fig.3.2.
"Table 2" of "Measurements of the pseudorapidity dependence of the total transverse energy in proton-proton collisions at sqrt(s) = 7 TeV with ATLAS"
2015
$E_{\perp}$ density for the dijet selection in the transverse region.