471 research outputs found
The Teleparallel Lagrangian and Hamilton-Jacobi Formalism
We analyze the Teleparallel Equivalent of General Relativity (TEGR) from the
point of view of Hamilton-Jacobi approach for singular systemsComment: 11 pages, no figures, to appear in GR
Excited States in 52Fe and the Origin of the Yrast Trap at I=12+
Excited states in 52Fe have been determined up to spin 10\hbar in the
reaction 28Si + 28Si at 115 MeV by using \gamma-ray spectroscopy methods at the
GASP array. The excitation energy of the yrast 10+ state has been determined to
be 7.381 MeV, almost 0.5 MeV above the well known \beta+-decaying yrast 12+
state, definitely confirming the nature of its isomeric character. The mean
lifetimes of the states have been measured by using the Doppler Shift
Attenuation method. The experimental data are compared with spherical shell
model calculations in the full pf-shell.Comment: 9 pages, RevTeX, 7 figures include
Spectroscopic studies of Dy-168,170 using CLARA and PRISMA
Preliminary results from an experiment aiming at Dy-170. Submitted to the LNL
Annual Report 2008.Comment: 2 pages, 4 figures, Submitted to the LNL Annual Report 200
Adjoint bi-continuous semigroups and semigroups on the space of measures
For a given bi-continuous semigroup T on a Banach space X we define its
adjoint on an appropriate closed subspace X^o of the norm dual X'. Under some
abstract conditions this adjoint semigroup is again bi-continuous with respect
to the weak topology (X^o,X). An application is the following: For K a Polish
space we consider operator semigroups on the space C(K) of bounded, continuous
functions (endowed with the compact-open topology) and on the space M(K) of
bounded Baire measures (endowed with the weak*-topology). We show that
bi-continuous semigroups on M(K) are precisely those that are adjoints of a
bi-continuous semigroups on C(K). We also prove that the class of bi-continuous
semigroups on C(K) with respect to the compact-open topology coincides with the
class of equicontinuous semigroups with respect to the strict topology. In
general, if K is not Polish space this is not the case
Pronounced Shape Change Induced by Quasiparticle Alignment
Mean lifetimes of high-spin states of 74Kr have been determined using the Doppler-shift attenuation method. The high-spin states were studied using the 40Ca(40Ca,α2p) reaction at a beam energy of 160 MeV with the GASP γ-ray spectrometer. The ground-state band and negative parity side band show the presence of three different configurations in terms of transitional quadrupole deformations. A dramatic shape change was found along the ground-state band after the S-band crossing. The deduced quadrupole deformation changes are well reproduced by cranked Woods-Saxon Strutinsky calculations
Population and y-decay studies of neutron-rich nuclei around 48Ca with deep inelastic collisions
The population and -decay of n-rich nuclei around 48Ca has been measured with the PRISMA-CLARA setup using deep-inelastic collisions (DIC) on 64Ni, at energies ~2.5 times above the Coulomb barrier. After a careful analysis of the response of the PRISMA magnetic spectrometer, a detailed investigation of the reaction properties is carried out. This provides total cross sections and energy integrated angular distributions of the most relevant transfer channels, which are compared with predictions from a semiclassical multi-nucleon transfer model. Good agreement is found for the 0p, 1p and 1n channels. In few cases, angular distributions of the first excited states are also measured and the experimental results are interpreted in terms of DWBA calculations, providing information on the basic ingredients of the theoretical models
238U(n, Îł) reaction cross section measurement with C 6D6 detectors at the n-TOF CERN facility
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 2.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly citedThe radiative capture cross section of 238U is very important for the developing of new reactor technologies and the safety of existing ones. Here the preliminary results of the 238U(n,Îł) cross section measurement performed at n-TOF with C6D6 scintillation detectors are presented, paying particular attention to data reduction and background subtraction.Peer reviewe
The nucleosynthesis of heavy elements in Stars : The key isotope 25Mg
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 2.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly citedWe have measured the radiative neutron-capture cross section and the total neutron-induced cross section of one of the most important isotopes for the s process, the 25Mg. The measurements have been carried out at the neutron time-of-flight facilities n-TOF at CERN (Switzerland) and GELINA installed at the EC-JRC-IRMM (Belgium). The cross sections as a function of neutron energy have been measured up to approximately 300 keV, covering the energy region of interest to the s process. The data analysis is ongoing and preliminary results show the potential relevance for the s process.Peer reviewe
Population of neutron-rich nuclei around 48ca with deep inelastic collisions
The deep inelastic reaction 48Ca+64Ni at 6 MeV/A has been studied using the CLARAâPRISMA setup. Angular distributions for pure elastic scattering and total cross-sections of the most relevant transfer channels have been measured. The experimental results are compared with predictions from a semiclassical model, showing good agreement for the presently analyzed few neutrons transfer channels. The decay of the most intense reaction products has also been studied, giving indications of the population of states with very short lifetimes.Gadea Raga, AndrĂ©s, [email protected]
Probing the nature of particleâcore couplings in 49Ca with Îł spectroscopy and heavy-ion transfer reactions
This work was supported by the Italian Istituto Nazionale di Fisica Nucleare and partially by the Spanish MICINN (ACI2009-1070 bilateral action) and Generalitat Valenciana (Grant Nos. BEST/2009/073 and PROMETEO/2010/101). The work has also been partially supported by the Polish Ministry of Science and Higher Education (Grant No. N N202 309135)
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