Search results for "scattering [nucleus nucleus]"
showing 10 items of 161 documents
Photoproduction of η and η′ mesons with EtaMAID
2016
The unitary isobar model EtaMAID has been updated with an extended list of nucleon resonances, fitted to recent and new data for differential cross sections and polarization observables. The nonresonant background is described by Regge trajectories of ω,ρ and a 1 , b 1 mesons and in addition Regge cuts, where vector and axial vector mesons are exchanged together with Pomeron and f 2 mesons.
Photo-production of tensor mesons
2016
Assuming that the f 2 (1270), f ′2 (1525), a 2 (1320), and K * 2 (1430) resonances are dynamically generated states from the vector meson-vector meson interactions in L = 0 and spin 2, we study the γp → f 2 (1270)[f ′2 (1525)]p , γp → a 0 2 (1320)p , and γp → K * 2 (1430)Λ(Σ) reactions. For the γp → f 2 (1270)p reaction, we find that the theoretical results for the differential cross sections are in good agreement with the experimental measurements and provide support for the molecular picture of the f 2 (1270) in the first baryonic reaction where it has been tested. Furthermore, we predict also the total and differential cross sections for other reactions. The results can be tested in futu…
ZZ production at hadron colliders in NNLO QCD
2014
We report on the first calculation of next-to-next-to-leading order (NNLO) QCD corrections to the inclusive production of ZZ pairs at hadron colliders. Numerical results are presented for pp collisions with centre-of-mass energy ($\sqrt{s}$) ranging from 7 to 14 TeV. The NNLO corrections increase the NLO result by an amount varying from $11\%$ to $17\%$ as $\sqrt{s}$ goes from 7 to 14 TeV. The loop-induced gluon fusion contribution provides about $60\%$ of the total NNLO effect. When going from NLO to NNLO the scale uncertainties do not decrease and remain at the $\pm 3\%$ level.
Neutron scattering and molecular correlations in a supercooled liquid
1999
We show that the intermediate scattering function $S_n(q,t)$ for neutron scattering (ns) can be expanded naturely with respect to a set of molecular correlation functions that give a complete description of the translational and orientational two-point correlations in the liquid. The general properties of this expansion are discussed with special focus on the $q$-dependence and hints for a (partial) determination of the molecular correlation functions from neutron scattering results are given. The resulting representation of the static structure factor $S_n(q)$ is studied in detail for a model system using data from a molecular dynamics simulation of a supercooled liquid of rigid diatomic m…
Measurement of the Coherent Neutron Scattering Length of (3) He.
2005
By means of neutron interferometry the s-wave neutron scattering length of the (3)He nucleus was re-measured at the Institut Laue-Langevin (ILL). Using a skew symmetrical perfect crystal Si-interferometer and a linear twin chamber cell, false phase shifts due to sample misalignment were reduced to a negligible level. Simulation calculations suggest an asymmetrically alternating measuring sequence in order to compensate for systematic errors caused by thermal phase drifts. There is evidence in the experiment's data that this procedure is indeed effective. The neutron refractive index in terms of Sears' exact expression for the scattering amplitude has been analyzed in order to evaluate the m…
Multi-frequency super-scattering from sub-wavelength graphene-coated nanotubes
2019
A cylindrical multilayered structure with three coupled graphene shells is shown to behave as a dual-band super-scatterer at mid-infrared frequencies. Under the 2D plasmonic nature of graphene material, multiple scattering resonances are attained in the deep subwavelength regime using an isotropic material. In the proposed structure, we efficiently exploit the existing three plasmonic resonances in each scattering channel. These resonances are tailored by dispersion engineering, which is simply displayed through the Bohr model applied to the associated planar structure. For the super-scatterer design, it is essential that the resonances of multiple channels coincide in a single frequency. H…
Strictly convex corners scatter
2017
We prove the absence of non-scattering energies for potentials in the plane having a corner of angle smaller than $\pi$. This extends the earlier result of Bl{\aa}sten, P\"aiv\"arinta and Sylvester who considered rectangular corners. In three dimensions, we prove a similar result for any potential with a circular conic corner whose opening angle is outside a countable subset of $(0,\pi)$.
Measurement of the high-mass Drell–Yan differential cross-section in pp collisions at s=7 TeV with the ATLAS detector
2013
This Letter reports a measurement of the high-mass Drell–Yan differential cross-section in proton–proton collisions at a centre-of-mass energy of 7 TeV at the LHC. Based on an integrated luminosity ...
Looking for magnetic monopoles at LHC with diphoton events
2012
Magnetic monopoles have been a subject of interest since Dirac established the relation between the existence of monopoles and charge quantization. The intense experimental search carried thus far has not met with success. The Large Hadron Collider is reaching energies never achieved before allowing the search for exotic particles in the TeV mass range. In a continuing effort to discover these rare particles we propose here other ways to detect them. We study the observability of monopoles and monopolium, a monopole-antimonopole bound state, at the Large Hadron Collider in the $\gamma \gamma$ channel for monopole masses in the range 500-1000 GeV. We conclude that LHC is an ideal machine to …
Semipermeable membrane to retain platinum atoms in the electrodeposition process of alpha spectrometry sources
1998
Abstract In earlier work alpha sources electrodeposited on stainless steel backings were analyzed by X-ray fluorescence (XRF) and Rutherford backscattering spectrometry (RBS) finding that during the electrodeposition process large quantities of platinum from the anode were deposited on the cathode surface jointly with the actinides. In the present work, a method to retain platinum atoms using an electrodeposition cell with a semipermeable membrane located between anode and cathode is proposed and tested. The XRF and RBS of alpha sources electrodeposited using this method show that there is less platinum on the stainless steel backing, thereby improving the quality of sources to be measured …