541 research outputs found
Self and Shared Leadership in Decision Quality: A Tale of Two Sides
Purpose
This study aims to investigate the relationship between shared leadership (SL) and decision quality, utilizing shared leadership theory (SLT) and behavioral decision theory (BDT). The authors will explore the mediating role of “decision comprehensiveness” in the SL–decision quality linkage. Additionally, the authors will examine how individual “self-leadership” and “debate” among team members moderate the relationship between SL and decision comprehensiveness.
Design/methodology/approach
The authors tested the hypothesized moderated mediation model using a sample of 506 professionals employed in 112 research and development (R&D) teams, along with their direct managers from large Italian firms. To examine the relationships, the authors employed confirmatory factor analyses and path analyses. In order to address endogeneity concerns, the authors incorporated an instrumental variable, namely delegation, into the analysis.
Findings
SL positively influences decision quality, mediated by decision comprehensiveness, where teams include comprehensive information in decision-making. The level of debate among team members positively moderates the SL–decision comprehensiveness relationship. High levels of self-leadership can harm SL by reducing decision comprehensiveness, indicating a downside. However, low or moderate levels of self-leadership do not harm decision comprehensiveness and can even benefit SL.
Originality/value
This is the first work to investigate the relationship between SL and decision quality, shedding light on the mechanisms underlying this association. By integrating SLT and BDT, the authors provide insights into how managers can make higher-quality decisions within self-leading teams. Moreover, this research makes a distinct contribution to the field of self-leadership by delineating its boundaries and identifying a potentially negative aspect within the self-influence process
Center-of-mass effects on the quasi-hole spectroscopic factors in the 16O(e,e'p) reaction
The spectroscopic factors for the low-lying quasi-hole states observed in the
16O(e,e'p)15N reaction are reinvestigated with a variational Monte Carlo
calculation for the structure of the initial and final nucleus. A computational
error in a previous report is rectified. It is shown that a proper treatment of
center-of-mass motion does not lead to a reduction of the spectroscopic factor
for -shell quasi-hole states, but rather to a 7% enhancement. This is in
agreement with analytical results obtained in the harmonic oscillator model.
The center-of-mass effect worsens the discrepancy between present theoretical
models and the experimentally observed single-particle strength. We discuss the
present status of this problem, including some other mechanisms that may be
relevant in this respect.Comment: 14 pages, no figures, uses Revtex, to be published in Phys. Rev. C 58
(1998
Correlation effects in single-particle overlap functions and one-nucleon removal reactions
Single-particle overlap functions and spectroscopic factors are calculated on
the basis of the one-body density matrices (ODM) obtained for the nucleus
employing different approaches to account for the effects of
correlations. The calculations use the relationship between the overlap
functions related to bound states of the (A-1)-particle system and the ODM for
the ground state of the A-particle system. The resulting bound-state overlap
functions are compared and tested in the description of the experimental data
from (p,d) reactions for which the shape of the overlap function is important.Comment: 11 pages, 4 figures include
Maximum occupation number for composite boson states
One of the major differences between fermions and bosons is that fermionic
states have a maximum occupation number of one, whereas the occupation number
for bosonic states is in principle unlimited. For bosons that are made up of
fermions, one could ask the question to what extent the Pauli principle for the
constituent fermions would limit the boson occupation number. Intuitively one
can expect the maximum occupation number to be proportional to the available
volume for the bosons divided by the volume occupied by the fermions inside one
boson, though a rigorous derivation of this result has not been given before.
In this letter we show how the maximum occupation number can be calculated from
the ground-state energy of a fermionic generalized pairing problem. A very
accurate analytical estimate of this eigenvalue is derived. From that a general
expression is obtained for the maximum occupation number of a composite boson
state, based solely on the intrinsic fermionic structure of the bosons. The
consequences for Bose-Einstein condensates of excitons in semiconductors and
ultra cold trapped atoms are discussed.Comment: 4 pages, Revte
Two-proton overlap functions in the Jastrow correlation method and cross section of the OC reaction
Using the relationship between the two-particle overlap functions (TOF's) and
the two-body density matrix (TDM), the TOF's for the
OC reaction are calculated on the
basis of a TDM obtained within the Jastrow correlation method. The main
contributions of the removal of and pairs from O
are considered in the calculation of the cross section of the
OC reaction using the Jastrow TOF's
which include short-range correlations (SRC). The results are compared with the
cross sections calculated with different theoretical treatments of the TOF's.Comment: 10 pages, 8 figures, ReVTeX
Quasiparticle properties in a density functional framework
We propose a framework to construct the ground-state energy and density
matrix of an N-electron system by solving selfconsistently a set of
single-particle equations. The method can be viewed as a non-trivial extension
of the Kohn-Sham scheme (which is embedded as a special case). It is based on
separating the Green's function into a quasi-particle part and a background
part, and expressing only the background part as a functional of the density
matrix. The calculated single-particle energies and wave functions have a clear
physical interpretation as quasiparticle energies and orbitals.Comment: 12 pages, 1 figure, to be published in Phys. Rev.
Quasiparticles in Neon using the Faddeev Random Phase Approximation
The spectral function of the closed-shell Neon atom is computed by expanding
the electron self-energy through a set of Faddeev equations. This method
describes the coupling of single-particle degrees of freedom with correlated
two-electron, two-hole, and electron-hole pairs. The excitation spectra are
obtained using the Random Phase Approximation, rather than the Tamm-Dancoff
framework employed in the third-order algebraic diagrammatic contruction
[ADC(3)] method. The difference between these two approaches is studied, as
well as the interplay between ladder and ring diagrams in the self-energy.
Satisfactory results are obtained for the ionization energies as well as the
energy of the ground state with the Faddeev-RPA scheme that is also appropriate
for the high-density electron gas.Comment: Revised manuscript. The working equations of the Faddeev-RPA method
are included in the Appendi
Overlap functions in correlation methods and quasifree nucleon knockout from O
The cross sections of the () and () reactions on O
are calculated, for the transitions to the ground state and the first
excited state of the residual nucleus, using single-particle overlap
functions obtained on the basis of one-body density matrices within different
correlation methods. The electron-induced one-nucleon knockout reaction is
treated within a nonrelativistic DWIA framework. The theoretical treatment of
the () reaction includes both contributions of the direct knockout
mechanism and of meson-exchange currents. The results are sensitive to details
of the different overlap functions. The consistent analysis of the reaction
cross sections and the comparison with the experimental data make it possible
to study the nucleon--nucleon correlation effects.Comment: 26 pages, LaTeX, 5 Postscript figures, submitted to PR
- …