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On a question of Demailly-Peternell-Schneider
This note aims to give an affirmative answer to an open question posed by
Demailly-Peternell-Schneider [DPS] in 2001 and recently by Peternell [P] again.
Let be a surjective morphism from a log canonical pair (X,D)
onto a -Gorenstein variety . If is nef, we show that
is pseudo-effective.Comment: J. Eur. Math. Soc. (to appear), minor corrections to some misleading
misprint
Chiral geometry and rotational structure for Cs in the projected shell model
The projected shell model with configuration mixing for nuclear chirality is
developed and applied to the observed rotational bands in the chiral nucleus
Cs. For the chiral bands, the energy spectra and electromagnetic
transition probabilities are well reproduced. The chiral geometry illustrated
in the and the is confirmed to be stable against the
configuration mixing. The other rotational bands are also described in the same
framework
Influence of pairing correlations on the radius of neutron-rich nuclei
The influence of pairing correlations on the neutron root mean square (rms)
radius of nuclei is investigated in the framework of self-consistent Skyrme
Hartree-Fock-Bogoliubov calculations. The continuum is treated appropriately by
the Green's function techniques. As an example the nucleus Zr is
treated for a varying strength of pairing correlations. We find that, as the
pairing strength increases, the neutron rms radius first shrinks, reaches a
minimum and beyond this point it expands again. The shrinkage is due to the the
so-called `pairing anti-halo effect', i. e. due to the decreasing of the
asymptotic density distribution with increasing pairing. However, in some
cases, increasing pairing correlations can also lead to an expansion of the
nucleus due to a growing occupation of so-called `halo' orbits, i.e. weakly
bound states and resonances in the continuum with low- values. In this
case, the neutron radii are extended just by the influence of pairing
correlations, since these `halo' orbits cannot be occupied without pairing. The
term `anti-halo effect' is not justified in such cases. For a full
understanding of this complicated interplay self-consistent calculations are
necessary.Comment: 18 pages, 5 figure
Static quadrupole moments of nuclear chiral doublet bands
The static quadrupole moments (SQMs) of nuclear chiral doublet bands are
investigated for the first time taking the particle-hole configuration
with triaxial deformation
parameters in the range as examples. The
behavior of the SQM as a function of spin is illustrated by analyzing the
components of the total angular momentum. It is found that in the region of
chiral vibrations the SQMs of doublet bands are strongly varying with ,
whereas in the region of static chirality the SQMs of doublet bands are almost
constant. Hence, the measurement of SQMs provides a new criterion for
distinguishing the modes of nuclear chirality. Moreover, in the high-spin
region the SQMs can be approximated by an analytic formula with a
proportionality to for both doublet bands. This provides a way to
extract experimentally the triaxial deformation parameter for chiral
bands from the measured SQMs.Comment: 7 pages, 4 figure
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