arXiv subjects

M. Horoi

Publications and source records attributed to M. Horoi.

40 records · Page 3Linked to original sources

arXiv2006

Half-life and spin of 60Mn^g

A value of 0.28 +/- 0.02 s has been deduced for the half-life of the ground state of 60Mn, in sharp contrast to the previously adopted value of 51 +/- 6 s. Access to the low-spin 60Mn ground state was accomplished via beta decay of the 0+ 60Cr parent nuclide. New, low-energy states in 60Mn have been identified from beta-delayed gamma-ray spectroscopy. The new, shorter half-life of 60Mn^g is not suggestive of isospin forbidden beta decay, and new spin and parity assignments of 1+ and 4+ have been adopted for the ground and isomeric beta-decaying states, respectively, of 60Mn.

nucl-ex↗

arXiv2005

Reaction and proton-removal cross sections of $^6$Li, $^7$Be, $^{10}$B, $^{9,10,11}$C, $^{12$N, $^{13,15}$O and $^{17}$Ne on Si at 15 to 53 MeV/nucleon

Excitation functions for total reaction cross sections, $σ_R$, were measured for the light, mainly proton-rich nuclei $^6$Li, $^7$Be, $^{10}$B, $^{9,10,11}$C, $^{12}$N, $^{13,15}$O, and $^{17}$Ne incident on a Si telescope at energies between 15 and 53 MeV/nucleon. The telescope served as target, energy degrader and detector. Proton-removal cross sections, $σ_{2p}$ for $^{17}$Ne and $σ_p$ for most of the other projectiles, were also measured. The strong absorption model reproduces the $A$-dependence of $σ_R$, but not the detailed structure. Glauber multiple scattering theory and the JLM folding model provided improved descriptions of the measured $σ_R$ values. $rms$ radii, extracted from the measured $σ_R$ using the optical limit of Glauber theory, are in good agreement with those obtained from high energy data. One-proton removal reactions are described using an extended Glauber model, incorporating second order noneikonal corrections, realistic single particle densities, and spectroscopic factors from shell model calculations.

nucl-ex↗

arXiv2004

New T=1 effective interactions for the f5/2 p3/2 p1/2 g9/2 model space; Implications for valence-mirror symmetry and seniority isomers

New shell model Hamiltonians are derived for the T=1 part of the residual interaction in the f5/2 p3/2 p1/2 g9/2 model space based on the analysis and fit of the available experimental data for 57Ni-78Ni isotopes and 77Cu-100Sn isotones. The fit procedure, properties of the determined effective interaction as well as new results for valence-mirror symmetry and seniority isomers for nuclei near 78Ni and 100Sn are discussed.

nucl-th↗

arXiv2000

Spectral Statistics of the Two-Body Random Ensemble Revisited

Using longer spectra we re-analyze spectral properties of the two-body random ensemble studied thirty years ago. At the center of the spectra the old results are largely confirmed, and we show that the non-ergodicity is essentially due to the variance of the lowest moments of the spectra. The longer spectra allow to test and reach the limits of validity of French's correction for the number variance. At the edge of the spectra we discuss the problems of unfolding in more detail. With a Gaussian unfolding of each spectrum the nearest neighbour spacing distribution between ground state and first exited state is shown to be stable. Using such an unfolding the distribution tends toward a semi-Poisson distribution for longer spectra. For comparison with the nuclear table ensemble we could use such unfolding obtaining similar results as in the early papers, but an ensemble with realistic splitting gives reasonable results if we just normalize the spacings in accordance with the procedure used for the data.

cond-mat↗