Search results for "LIMIT"
showing 10 items of 2826 documents
Decay properties of265Sg(Z=106)and266Sg(Z=106)
1998
The presently known most neutron-rich isotopes of element 106 (seaborgium, Sg), {sup 265}Sg and {sup 266}Sg, were produced in the fusion reaction {sup 22}Ne+{sup 248}Cm at beam energies of 121 and 123 MeV. Using the On-Line Gas chemistry Apparatus OLGA, a continuous separation of Sg was achieved within a few seconds. Final products were assayed by {alpha}-particle and spontaneous fission (SF) spectrometry. {sup 265}Sg and {sup 266}Sg were identified by observing time correlated {alpha}-{alpha}-({alpha}) and {alpha}-SF decay chains. A total of 13 correlated decay chains of {sup 265}Sg (with an estimated number of 2.8 random correlations) and 3 decay chains of {sup 266}Sg (0.6 random correlat…
RPA susceptibility of asymmetric nuclear matter at finite temperatures with Skyrme interactions
1997
Abstract We investigate the thermal RPA response of asymmetric nuclear matter interacting through various Skyrme interactions characterized by the value of the effective nucleon mass. Our study concentrates on the evolution of collective states according to the variations of the transferred momentum, temperature and asymmetry ratio. The differences and similarities between the roles of neutron excess and of thermal excitation are discussed. It is shown that the limit of meaningful nuclear asymmetries, namely Y close to 1/3, must be reached in order to observe sizable effects in the structure patterns, a fact that brings support to calculations of dynamical response that resort to symmetric …
Investigation of the Δn = 0 selection rule in Gamow-Teller transitions: The β-decay of 207Hg
2019
5 pags., 3 figs., 1 tab. -- Open Access funded by Creative Commons Atribution Licence 4.0
Tz=−1→0βdecays ofNi54,Fe50,Cr46, andTi42and comparison with mirror(He3,t)measurements
2015
We have studied the β decay of the Tz=−1, f7/2 shell nuclei Ni54, Fe50, Cr46, and Ti42 produced in fragmentation reactions. The proton separation energies in the daughter Tz=0 nuclei are relatively large (≈4–5 MeV) so studies of the γ rays are essential. The experiments were performed at GSI as part of the Stopped-beam campaign with the RISING setup consisting of 15 Euroball Cluster Ge detectors. From the newly obtained high precision β-decay half-lives, excitation energies, and β branching ratios, we were able to extract Fermi and Gamow-Teller transition strengths in these β decays. With these improved results it was possible to compare in detail the Gamow-Teller (GT) transition strengths …
Search for the decay ϕ→K0K¯0γ with the KLOE experiment
2009
Abstract We have searched for the decay ϕ → K 0 K ¯ 0 γ , by detecting K S pairs plus a photon and with the K S -mesons decaying to π + π − , in a sample of about 1.5 × 10 9 ϕ-decays collected by the KLOE experiment at DAΦNE. The reaction proceeds through the intermediate states f 0 ( 980 ) γ , a 0 ( 980 ) γ . We find five events with 3.2 events expected from background processes. We obtain the upper limit: BR ( ϕ → K 0 K ¯ 0 γ ) 1.9 × 10 − 8 at 90% CL.
Mission: Impossible (Escape from the Lyman Limit)
2003
We investigate the intrinsic opacity of high-redshift galaxies to outgoing ionising photons using high-quality photometry of a sample of 27 spectroscopically-identified galaxies of redshift 1.9<z<3.5 in the Hubble Deep Field. Our measurement is based on maximum-likelihood fitting of model galaxy spectral energy distributions-including the effects of intrinsic Lyman-limit absorption and random realizations of intervening Lyman-series and Lyman-limit absorption-to photometry of galaxies from space- and ground-based broad-band images. Our method provides several important advantages over the methods used by previous groups, including most importantly that two-dimensional sky subtraction of fai…
One-dimensional error-diffusion technique adapted for binarization of rotationally symmetric pupil filters
1995
Abstract Two novel algorithms for the binarization of continuous rotationally symmetric real and positive pupil filters are presented. Both algorithms are based on the one-dimensional error diffusion concept. In our numerical experiment an original gray-tone apodizer is substituted by a set of transparent and opaque concentric annular zones. Depending on the algorithm the resulting binary mask consists of either equal width or equal area zones. The diffractive behavior of binary filters is evaluated. It is shown that the filter with equal width zones gives Fraunhofer diffraction pattern more similar to that of the original gray-tone apodizer than that with equal area zones, assuming in both…
Two-dimensional quantum scattering by non-isotropic interactions localized on a circle, applications to open billiards
2018
Two-dimensional quantum scattering by isotropic and non-isotropic interactions localized on a circle is considered. The expansion of the interaction on the circle in a Fourier series allows us to express basic objects of scattering theory (resolvent, T operator, differential cross length, cross length, and cross length averaged over all orientations of the incident particle), in terms of operations on matrices. For numerical applications, these matrices are truncated to a given order. If the interaction is isotropic, this general formulation reduces to the usual one, and the resonances in the isotropic cases are studied because they allow us to interpret resonances in some non-isotropic cas…
Comparison of two non-primitive methods for path integral simulations: Higher-order corrections vs. an effective propagator approach
2002
Two methods are compared that are used in path integral simulations. Both methods aim to achieve faster convergence to the quantum limit than the so-called primitive algorithm (PA). One method, originally proposed by Takahashi and Imada, is based on a higher-order approximation (HOA) of the quantum mechanical density operator. The other method is based upon an effective propagator (EPr). This propagator is constructed such that it produces correctly one and two-particle imaginary time correlation functions in the limit of small densities even for finite Trotter numbers P. We discuss the conceptual differences between both methods and compare the convergence rate of both approaches. While th…
Radiating and nonradiating behavior of hyperbolic-secant, raised-cosine, and Gaussian input light pulses in dispersion-managed fiber systems.
2005
We address the problem of optical light pulses, called dressed pulses, which do not match the stationary pulse profile of a dispersion-managed (DM) fiber system and we theoretically analyze the associated radiation. Comparing hyperbolic-secant, raised-cosine, and Gaussian pulse envelopes, we show that the general radiation figure is highly sensitive to the input pulse profile. As common general features for these pulse profiles, we find a rich variety of dynamical states that includes weak-, moderate-, and strong-radiation states, depending on the map strength of the DM fiber system. We demonstrate the existence of two intervals of map strengths where the emitted radiation is of considerabl…