Search results for "Focu"
showing 10 items of 1182 documents
Short-range fundamental forces
2011
Abstract We consider theoretical motivations to search for extra short-range fundamental forces as well as experiments constraining their parameters. The forces could be of two types: 1) spin-independent forces; 2) spin-dependent axion-like forces. Different experimental techniques are sensitive in respective ranges of characteristic distances. The techniques include measurements of gravity at short distances, searches for extra interactions on top of the Casimir force, precision atomic and neutron experiments. We focus on neutron constraints, thus the range of characteristic distances considered here corresponds to the range accessible for neutron experiments.
Scherk-Schwarz reduction of D=5 special and quaternionic geometry
2004
We give the N=2 gauged supergravity interpretation of a generic D=4, N=2 theory as it comes from generalized Scherk-Schwarz reduction of D=5, N=2 (ungauged) supergravity. We focus on the geometric aspects of the D=4 data such as the general form of the scalar potential and masses in terms of the gauging of a ``flat group''. Higgs and super-Higgs mechanism are discussed in some detail.
LHC phenomenology of supersymmetric models beyond the MSSM
2010
Contribution to the 16th International Symposium on Particles, Strings and Cosmology (PASCOS 2010). Valencia (Spain). July 19-23, 2010
Improving on numerical simulations of nonlinear CMB anisotropies
2015
An Adaptative-Particle-Particle-Particle-Mesh code (HYDRA) plus a ray-tracing procedure was used in [1] to perform an exhaustive analysis of the weak lensing anisotropy. Other nonlinear Cosmic Microwave Background anisotropies, such as the Rees-Sciamaand the Sunyaev-Zel.dovicheffects are also being studied by using the same tools. Here we present some advances in our study of these nonlinear anisotropies. The primary advance is due to the use of better simulations with greater particle densities and appropriate softening, although other parameters have also been adjusted to get better estimates. Thus, we improve on a previous paper [2] where the Rees-Sciamaeffect was studied with Particle-M…
Future axion searches with the International Axion Observatory (IAXO)
2013
Çetin, Serkant Ali (Dogus Author) -- Conference full title: 6th Symposium on Large TPCs for Low Energy Rare Event Detection; Paris; France; 17 December 2012 through 19 December 2012. The International Axion Observatory (IAXO) is a new generation axion helioscope aiming at a sensitivity to the axion-photon coupling of gaγ ∼ few × 10-12 GeV-1, i.e. 1-1.5 orders of magnitude beyond the one achieved by CAST, currently the most sensitive axion helioscope. The main elements of IAXO are an increased magnetic field volume together with extensive use of x-ray focusing optics and low background detectors, innovations already successfully tested in CAST. Additional physics cases of IAXO could include …
The European Photon Imaging Camera on XMM-Newton: The MOS Cameras
2000
The EPIC focal plane imaging spectrometers on XMM-Newton use CCDs to record the images and spectra of celestial X-ray sources focused by the three X-ray mirrors. There is one camera at the focus of each mirror; two of the cameras contain seven MOS CCDs, while the third uses twelve PN CCDs, defining a circular field of view of 30 arcmin diameter in each case. The CCDs were specially developed for EPIC, and combine high quality imaging with spectral resolution close to the Fano limit. A filter wheel carrying three kinds of X-ray transparent light blocking filter, a fully closed, and a fully open position, is fitted to each EPIC instrument. The CCDs are cooled passively and are under full clos…
Transition from plasma-driven to Kerr-driven laser filamentation.
2011
While filaments are generally interpreted as a dynamic balance between Kerr focusing and plasma defocusing, the role of the higher-order Kerr effect (HOKE) is actively debated as a potentially dominant defocusing contribution to filament stabilization. In a pump-probe experiment supported by numerical simulations, we demonstrate the transition between two distinct filamentation regimes at 800 nm. For long pulses (1.2 ps), the plasma substantially contributes to filamentation, while this contribution vanishes for short pulses (70 fs). These results confirm the occurrence, in adequate conditions, of filamentation driven by the HOKE rather than by plasma.
In vitro power profiles of multifocal simultaneous vision contact lenses.
2013
Abstract Purpose To evaluate the power profile of multifocal contact lenses (CLs) using a new technology based on quantitative deflectometry. Methods The Nimo TR1504 was used to analyze the power distribution of multifocal CLs. The CLs under study were: Air Optix Aqua Multifocal Low, Medium and High Addition and Focus Progressives. Three lenses of each model were considered. Results All multifocal CLs showed a power profile characterized by a change toward more positive power values when aperture sizes become smaller. The near refractive addition of the lenses under study was +2.61 D, +1.44 D, +1.30 D and +0.30 D for the Focus Progressives, the Air Optix Aqua Multifocal High, Medium Add and…
Hydrodynamic simulation of elliptic flow
1999
We use a hydrodynamic model to study the space-time evolution transverse to the beam direction in ultrarelativistic heavy-ion collisions with nonzero impact parameters. We focus on the influence of early pressure on the development of radial and elliptic flow. We show that at high energies elliptic flow is generated only during the initial stages of the expansion while radial flow continues to grow until freeze-out. Quantitative comparisons with SPS data from semiperipheral Pb+Pb collisions suggest the applicability of hydrodynamical concepts already $\approx$ 1 fm/c after impact.
From R_AA via correlations to jets - the long road to tomography
2009
The main motivation to investigate hard probes in heavy ion collisions is to do tomography, i.e. to infer medium properties from the in-medium modification of hard processes. Yet while the suppression of high P_T hadrons has been measured for some time, solid tomographic information is slow to emerge. This can be traced back to theoretical uncertainties and ambiguities in modelling both medium evolution and parton-medium interaction. Ways to overcome these difficulties are to constrain models better and to focus on more differential observables. Correlations of high P_T hadrons offer non-trivial information beyond what can be deduced from single hadron suppression. They reflect not only the…