252 research outputs found
Corporate Philanthropy in Top Romanian Companies
No full textThis paper aims to provide an insight on the CSR activities developed by top Romanian companies and to analyze whether some economic indexes as number of employees and turnover have a considerable impact on the decision of companies to involve in social responsible activities. The approach is based on a cross-analysis of the statistical weight of donations for eight top company donors in 2007 in Romania. By reviewing the results of the research, the author considers the opportunity to develop a case for CSR, even in its basic form: philanthropy, as a premise for long run social performance.corporate philanthropy, corporate social responsibility, microeconomic indexes, stakeholders.
Exotic rotations and seniority isomers in Nd nuclei
No full textWe have recently studied the Nd nuclei up to very high spins and identified several bands, which were interpreted as the manifestation of various types of collective motion: tilted axis rotation, principal axis rotation along the short and long axes, wobbling motion, chiral bands. All these types of excitation have been observed in 138Nd and are discussed in the framework of the tilted axis cranking (TAC) and cranked Nilsson-Strutinsky (CNS) models
Robustness of chiral symmetry in atomic nuclei with reflection-asymmetric shapes
No full textInternational audienceThe present paper is a comment regarding the robustness of the chirality in presence of the space-reflection asymmetry, which leads to pairs of interleaved positive- and negative-parity bands. The recent results reported in Ref. \cite{2006.12062} which introduced the and quantum numbers to describe an ideal nuclear system with simultaneous chiral and reflection symmetry breaking, are commented
Chirality in nuclear structure: An experimental view into underlying symmetries
No full textThe experimental information on the observed nearly degenerate bands in the N = 75 isotones, in particular 134Pr, which is considered as the best candidate for chiral bands, if critically analyzed, shows that most properties of the bands, in particular the recently measured branching ratios and lifetimes, are in clear disagreement with the interpretation of the two bands as chiral bands. For I = 14 - 18 in 134Pr, where the observed energies are almost degenerate, a value of 2.0(4) for the ratio of the transition quadrupole moments of the two bands was obtained, which implies a considerable difference in the nuclear shape associated with the two bands. The insufficiency of the near-degeneracy criterion to trace nuclear chirality is clearly emphasized
Smooth band termination in I
No full textInternational audienceThe cranked Nilsson-Strutinsky formalism is employed to investigate the band structure of I from low to high spin. A set of eight rotational bands with well established spins and parities are analyzed. Five bands start at low spin and are assigned to the single-particle proton orbitals (, ), , and , which are close to the Z=53 Fermi surface for a deformation of . The analysis of the observed level energies relative to a rotating liquid drop and spins versus -ray energies allow to track the evolution of the configurations with increasing spin. It is of special interest that one band in the valence space is observed to a smooth termination at
Comment on "First Observation of Multiple Transverse Wobbling Bands of Different Kinds in Au [Phys. Rev. Lett. 125, 132501 (2015)]"
No full textInternational audienceIn [S. Nandi et al., Phys. Rev. Lett. 125, 132501 (2020)] two transverse wobbling bands were reported in Au. The critical experimental proof for this assignment is the E2 dominated linking transitions between the wobbling and normal bands, which are supported by fitting the measured DCO ratio and polarization results. However, the uncertainties are significantly underestimated according to an analysis on the statistical error. With reasonable error, the mixing ratios cannot be exclusively decided, and the M1 dominated character cannot be excluded, indicating that the wobbling assignment is still questionable
Comment on "Erratum: Negative-parity high-spin states and a possible magnetic rotation band in Pr [Phys. Rev. C 92, 054325 (2015)]"
No full textInternational audienceIn [Ritika Garg et al., Phys. Rev. C 100, 069901(E) (2019)] the experimental results on the polarization asysmetry were revised due to a claimed change of the geometry asymmetry. However, the revised results can not be reproduced as claimed in the erratum by simply changing the geometry asymmetry in extracting the polarization asymmetry, without re-extracting the polarization asymmetry from the original experimental data. It is possible that the quoted errors were significantly underestimated
Comment on "Transverse Wobbling in Pr [Phys. Rev. Lett. 114, 082501 (2015)]"
No full textInternational audienceIn [J. T. Matta et al., Phys. Rev. Lett. 114, 082501 (2015)] a transverse wobbling band was reported in Pr. The critical experimental proof for this assignment is the E2 dominated linking transitions between the wobbling and normal bands, which are supported by two experiments performed with Gammasphere and INGA. However, the M1 dominated character cannot be excluded based on the reported experimental information, indicating that the wobbling assignment is still questionable
Microscopic investigation on the existence of transverse wobbling under the effect of rotational alignment: The Nd case
No full textInternational audienceThe even- and odd-spin two-quasiparticle yrast bands in Nd136 are investigated with the triaxial projected shell model, focusing on the possible interpretation as transverse wobbling. With the experimental observables reproduced reasonably, the conditions under which the wobbling approximation is valid are examined via the angular momentum geometry and the configuration components extracted from the microscopic wave functions. The impact of the rotational alignment of the quasiparticles on the scenario of transverse wobbling is emphasized. It turns out that the n=0 band of the wobbling candidate is more affected than the n=1 one, which tends to go against the decreasing trend of the wobbling energy expected in the transverse case
Chiral bands in 135Nd: The interacting boson-fermion model approach
No full textThe chiral interpretation of negative-parity twin bands in the odd-A 135Nd nucleus was investigated in the interacting boson-fermion model. The IBFM calculation shows that the dominant role in the formation of the chiral pattern has the exchange interaction, i.e., the antisymmetrization of odd fermions with the fermion structure of the bosons. The structure of the twin bands in 137Nd has also been investigated, concluding that it is determined by shape fluctuations and prolate-oblate coexistence rather than by chirality
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