Search results for "signal processing"
showing 10 items of 2451 documents
Observation of TeV gamma-rays from the unidentified source HESS J1841-055 with the ARGO-YBJ experiment
2013
We report the observation of a very high energy \gamma-ray source, whose position is coincident with HESS J1841-055. This source has been observed for 4.5 years by the ARGO-YBJ experiment from November 2007 to July 2012. Its emission is detected with a statistical significance of 5.3 standard deviations. Parameterizing the source shape with a two-dimensional Gaussian function we estimate an extension \sigma=(0.40(+0.32,-0.22}) degree, consistent with the HESS measurement. The observed energy spectrum is dN/dE =(9.0-+1.6) x 10^{-13}(E/5 TeV)^{-2.32-+0.23} photons cm^{-2} s^{-1} TeV^{-1}, in the energy range 0.9-50 TeV. The integral \gamma-ray flux above 1 TeV is 1.3-+0.4 Crab units, which is…
CP and T violation in neutrino oscillations
2000
The conditions to induce appreciable CP-and T-odd effects in neutrino oscillations are discussed. The propagation in matter leads to fake CP-and CPT-odd asymmetries, besides a Bohm-Aharonov type modification of the interference pattern. We study the separation of fake and genuine CP violation by means of energy and distance dependence.
Standard model large-ETprocesses and searches for new physics at HERA
1999
Existing and missing calculations of standard model processes producing large transverse energy in electron-proton interactions at HERA are reviewed. The adequacy of the existing standard model Monte Carlo programs for generic searches of exotic processes is analyzed.
Higher-Order Differential Operators on a Lie Group and Quantization
1995
This talk is devoted mainly to the concept of higher-order polarization on a group, which is introduced in the framework of a Group Approach to Quantization, as a powerful tool to guarantee the irreducibility of quantizations and/or representations of Lie groups in those anomalous cases where the Kostant-Kirilov co-adjoint method or the Borel-Weyl-Bott representation algorithm do not succeed.
van der Waals Interaction Energy Between Two Atoms Moving With Uniform Acceleration
2013
We consider the interatomic van der Waals interaction energy between two neutral ground-state atoms moving in the vacuum space with the same uniform acceleration. We assume the acceleration orthogonal to their separation, so that their mutual distance remains constant. Using a model for the van der Waals dispersion interaction based on the interaction between the instantaneous atomic dipole moments, which are induced and correlated by the zero-point field fluctuations, we evaluate the interaction energy between the two accelerating atoms in terms of quantities expressed in the laboratory reference frame. We find that the dependence of the van der Waals interaction between the atoms from the…
Antideuterons as an indirect dark matter signature: design and preparation for a balloon-born GAPS experiment
2008
The General Antiparticle Spectrometer (GAPS) exploits low energy antideuterons produced in neutralino-neutralino annihilations as an indirect dark matter (DM) signature that is effectively free from background. When an antiparticle is captured by a target material, it forms an exotic atom in an excited state which quickly decays by emitting X-rays of precisely defined energy and a correlated pion signature from nuclear annihilation. We have successfully demonstrated the GAPS method in an accelerator environment and are currently planning a prototype flight from Japan for 2009. This will lead to a long duration balloon (LDB) mission that will complement existing and planned direct DM searche…
Real-time switching between multiple steady-states in quantum transport
2010
Creative Commons Attribution License 3.0.
Investigation of the elastic and inelastic scattering of 4He from 11B in the energy range 29-50.5 MeV
2018
We have measured the angular distributions for the elastic and inelastic scattering of 4He from 11B in the isochronous cyclotron U-150 M INP RK. The extracted α-particles beam has been accelerated to energy 29 MeV and then directed to 11B target. The experimental results were analyzed within the framework of both the optical model using different complex potential and the double folding potential obtained with different density-dependent NN interactions which give the corresponding values of the nuclear incompressibility K in the Hartree-Fock calculation of nuclear matter.
Energy- and time-resolved microscopy using PEEM: recent developments and state-of-the-art
2008
Two novel methods of spectroscopic surface imaging are discussed, both based on photoemission electron microscopy PEEM. They are characterised by a simple electron-optical set up retaining a linear column. An imaging high-pass energy filter has been developed on the basis of lithographically-fabricated microgrids. Owing to a mesh size of only 7μm, no image distortions occur. The present energy resolution is 70 meV. The second approach employs time-of-flight energy dispersion and time-resolved detection using a Delayline Detector. In this case, the drift energy and the time resolution of the detector determine the energy resolution. The present time resolution is 180 ps, giving rise to an en…
Infinite single-particle bandwidth of a Mott–Hubbard insulator
2016
The conventional viewpoint of the strongly correlated electron metal-insulator transition is that a single band splits into two upper and lower Hubbard bands at the transition. Much work has investigated whether this transition is continuous or discontinuous. Here we focus on another aspect and ask the question of whether there are additional upper and lower Hubbard bands, which stretch all the way out to infinity — leading to an infinite single-particle bandwidth (or spectral range) for the Mott insulator. While we are not able to provide a rigorous proof of this result, we use exact diagonalization studies on small clusters to motivate the existence of these additional bands, and we discu…