Search results for "Computer Science Application"

Constraints on light asymmetric dark matter from solar neutrinos

2010

We study the effect of dark matter (DM) particles in the Sun, focusing in particular on the possible reduction of the solar neutrinos flux due to the energy carried away by DM particles from the innermost regions of the Sun, and to the consequent reduction of the temperature of the solar core. In the very low-mass range between 4 and 10 GeV, recently advocated to explain the findings of the DAMA and CoGent experiments, the effects on neutrino fluxes are detectable only for DM models with very small, or vanishing, self-annihilation cross section, such as the so-called asymmetric DM models, and we study the combination of DM masses and Spin Dependent cross sections which can be excluded with …

Laser spectroscopy at the experimental storage ring - an overview

2012

We present an overview of laser spectroscopy experiments at the experimental storage ring of GSI in Darmstadt, which have been and will be performed in the near future.

Compton transmission polarimeter for a very precise polarization measurement within a wide range of electron currents

2011

For new experiments with polarized electron and positron beams the precise and quick measurement of the beam polarization is required. The relative electron polarization has been monitored on-line using a compact transmission Compton polarimeter for a wide range of average electron currents up to 100/μA and electron beam energy of 3.5 MeV. The asymmetry induced by the beam polarization can be monitored precisely with ΔA/A < 0.2 %. Even small relative variations of the beam polarization during a beam time may be detected using this polarimeter, such as an increase ~ 1 % and subsequent decrease of the beam polarization.

Direct numerical simulation of MR suspension: The role of viscous and magnetic interactions between particles

2009

A numerical method is developed with aim to simulate the magnetorheological (MR) suspension taking into account realistic magnetic forces. The MR suspension is described by spherical particles with nonlinear magnetic properties suspended in a shear flow. Inertia effects, Brownian motion and buoyancy forces are neglected. The hydrodynamic interaction between close particles is taken into account approximately. Results of some test simulations are presented.

Statistical analysis of the influence of forces on particles in EM driven recirculated turbulent flows

2011

The present paper contains an analysis of the statistical distribution of forces affecting non-conducting particles dispersed in an EM induced recirculated flow in induction furnaces. The simulation is conducted adopting the LES-based Euler-Lagrange approach in the limit of dilute conditions (one-way coupling). It is done by means of a development of OpenFOAM software code. The used Lagrange equation for particle tracking includes drag, EM, buoyancy, lift, acceleration and added mass forces. The relevant approximations for the forces are chosen on the basis of the statistical analysis of the non-dimensional parameters (particle Reynolds number, shear stress and acceleration parameter). The …

Lifetime measurements in mirror nuclei31S and31P: A test for isospin mixing

2011

Using the 20Ne + 12C fusion-evaporation reaction at E20Ne = 33 MeV and the multidetector array GASP in conjuction with the EUCLIDES charged particle detector, angular correlations of coincident pairs of γ transitions and lifetimes in mirror nuclei 31S and 31P have been measured at the Piave-Alpi accelerator of the Laboratori Nazionali di Legnaro. A comparison of the determined B(E1) strengths of the analog mirror 7/2− → 5/2+ transitions indicates the presence of a violation of isospin symmetry.

Baryon chiral perturbation theory

2009

We provide a short introduction to the one-nucleon sector of chiral perturbation theory and address the issue of power counting and renormalization. We discuss the infrared regularization and the extended on-mass-shell scheme. Both allow for the inclusion of further degrees of freedom beyond pions and nucleons and the application to higher-loop calculations. As applications we consider the chiral expansion of the nucleon mass to order ${\cal O}(q^6)$ and the inclusion of vector and axial-vector mesons in the calculation of nucleon form factors. Finally, we address the complex-mass scheme for describing unstable particles in effective field theory.

Some Evidence of the Cluster Struture Inside of9Be

2017

Gravitational waves in Fully Constrained Formulation in a dynamical spacetime with matter content

2011

We analyze numerically the behaviour of the hyperbolic sector of the Fully Constrained Formulation (FCF) (Bonazzola et al. 2004). The numerical experiments allow us to be confident in the performances of the upgraded version of the CoCoNuT code (Dimmelmeier et al. 2005) by replacing the Conformally Flat Condition (CFC), an approximation of Einstein equations, by FCF. First gravitational waves in FCF in a dynamical spacetime with matter content will be shown.

Dynamical spacetimes and gravitational radiation in a Fully Constrained Formulation

2010

This contribution summarizes the recent work carried out to analyze the behavior of the hyperbolic sector of the Fully Constrained Formulation (FCF) derived in Bonazzola et al. 2004. The numerical experiments presented here allows one to be confident in the performances of the upgraded version of CoCoNuT's code by replacing the Conformally Flat Condition (CFC) approximation of the Einstein equations by the FCF.