Search results for "design [electronics]"
showing 10 items of 505 documents
Quasi-particle and plasmaron properties in the electron gas
1972
The self-energy function of the degenerate electron gas is studied in an approximation which uses the dielectric function proposed by Singwi, Tosi, Land and Sjolander, and neglects the corresponding vertex corrections. Two contributions to the self-energy are distinguished which arise from the plasmon pole and the particle-hole continuum respectively. Comparison of the results is made with the analogous approximation to the self-energy which uses the RPA dielectric function, and with a further, simplified approximation. Subsequently the properties of the usual quasi-particle and of the plasmaron are calculated. Nummerically, the most significant effect found is a 25% reduction of the plasma…
Final State Interaction Effects in 3He(e ,e'p)
2003
Abstract Asymmetries in quasi-elastic 3 He ( e → , e ′ p ) have been measured at a momentum transfer of 0.67 (GeV/ c ) 2 and are compared to a calculation which takes into account relativistic kinematics in the final state and a relativistic one-body current operator. With an exact solution of the Faddeev equation for the 3 He -ground state and an approximate treatment of final state interactions in the continuum good agreement is found with the experimental data.
STUDY OF SHORT-LIVED SILVER ISOTOPES WITH A LASER ION-SOURCE
1995
A chemically selective laser ion source based on resonance ionization of atoms in a hot cavity has been applied for the study of short-lived silver isotopes at CERN/ ISOLDE. Silver atoms were ionized by two resonant excitations and final laser ionization into the continuum. Decay properties of the neutron-rich isotopes121–127Ag were studied with a neutron long-counter and aβ-detector.
Radiative pion capture in nuclei: a continuum shell-model approach
1997
The radiative pion capture process in nuclei is approached by using a continuum shell-model description of the nucleus, together with a phenomenological treatment of the two particle-two hole effects. It is found that these effects play an important role to reproduce the observed experimental photon energy distribution. This distribution as well as the integrated one depends significantly on the details of the mean field potential. This makes this process interesting to investigate the nuclear structure dynamics.
φ, ϱ, and ω production in pU, OU and SU reactions at 200 GeV per nucleon
1991
Abstract Low mass muon pair production at high P T and low X F studied in pU, OU and SU 200 GeV per nucleon react ions. When energy density or projectile mass are increased, φ production is enhanced as compared with the yield of muon pairs in the mass continuum (1.7 M μμ c 2 ), whereas the production of ω and ϱ, experimentally unresolved, remains approximately constant. This φ enhancement is in agreement with predictions based on quark-gluon plasma formation and, together with the previously reported J/Ψ suppression, puts severe constraints on a purely hadronic description of nucleus-nucleus collisions.
Transverse energy distributions in nucleus-nucleus collisions at 200 GeV/nucleon
1990
Abstract The transverse energy ET distributions of nucleus-nucleus collisions are studied in the framework of a simple geometrical model. The distributions for inclusive production of J ψ and muon pairs in the mass continuum are analyzed. The shape of the ET distribution of the continuum agreed with the model. The previously oberved decrease of the ratio ( J ψ )/continuum with increasing ET is due to the behavior of the J ψ .
Study of J/$\psi$ production in p-U, O-U and S-U interactions at 200 GeV per nucleon
1991
Abstract In a search for quark-gluon plasma formation, the production of J/ψ and muon pairs in the mass continuum region is studied in oxygen-uranium and sulphur-uranium interactions. The yield of J/ψ relative to the continuum is measured to be a decreasing function of the neutral transverse energy produced in the collision, i.e. of the energy density. A comparison is made with proton-uranium reactions.
A BeppoSAX study of the Galactic Z-source GX 340+0
2004
Abstract We present the results of a BeppoSAX broad band (0.1–200 keV) observation of the Z-source GX 340+0. The 1.8–30 keV continuum is well described by a blackbody ( kT BB ∼0.5 keV) plus a Comptonized component with seed photons temperature ∼ 1 keV and electron temperature ∼ 3 keV. A hard tail dominates the spectrum above 30 keV. It can be fitted using a bremsstrahlung component or, equivalently, a powerlaw (with a low-energy cutoff). We detect also a Gaussian line at ∼6.8 keV and an absorption edge at ∼9.2 keV. A low-energy (∼1 keV) unresolved feature needs further investigations.
Neutron capture cross sections for neutron-rich isotopes
1985
Average continuum (Hauser-Feshbach) and resonance (Breit-Wigner) neutron capture rates for neutron-rich isotopes, determined on the basis of recent experimental nuclear physics input parameters, are compared to earlier theoretical reaction rates commonly used in astrophysical model computations.
STUDIES OF 12C USING β-DECAYS
2008
The nuclear structure of states in 12 C have been a subject of interest for both theory and experiment since the early days of nuclear physics. Many open questions remain, especially concerning the existence and properties of 0+ and 2+ states in the triple alpha continuum. A series of experiments have been performed using β-decay of 12 N and 12 B to probe these states. The latest experiment was performed at KVI using an implantation method, measuring the sum energy of the three α-particles directly. Preliminary results from this experiment will be presented.