85,275 research outputs found
Multiple Chirality in Nuclear Rotation: A Microscopic View
Covariant density functional theory and three-dimensional tilted axis
cranking are used to investigate multiple chirality in nuclear rotation for the
first time in a fully self-consistent and microscopic way. Two distinct sets of
chiral solutions with negative and positive parities, respectively, are found
in the nucleus 106Rh. The negative-parity solutions reproduce well the
corresponding experimental spectrum as well as the B(M1)/B(E2) ratios of the
transition strengths. This indicates that a predicted positive-parity chiral
band should also exist. Therefore, it provides a further strong hint that
multiple chirality is realized in nuclei.Comment: 15 pages, 5 figures, 1 tabl
Is the CMB asymmetry due to the kinematic dipole?
Parity violation found in the Cosmic Microwave Background (CMB) radiation is
a crucial clue for the non-standard cosmological model or the possible
contamination of various foreground residuals and/or calibration of the CMB
data sets. In this paper, we study the directional properties of the CMB parity
asymmetry by excluding the modes in the definition of parity parameters.
We find that the preferred directions of the parity parameters coincide with
the CMB kinematic dipole, which implies that the CMB parity asymmetry may be
connected with the possible contamination of the residual dipole component. We
also find that such tendency is not only localized at , but in the
extended multipole ranges up to .Comment: 17 pages, 5 figures, 2 tables, improved version, ApJ accepte
Impact of pairing correlations on the orientation of the nuclear
For the first time, the tilted axis cranking covariant density functional
theory with pairing correlations has been formulated and implemented in a fully
self-consistent and microscopic way to investigate the evolution of the spin
axis and the pairing effects in rotating triaxial nuclei. The measured energy
spectrum and transition probabilities for the Nd-135 yrast band are reproduced
well without any ad hoc renormalization factors when pairing effects are taken
into account. A transition from collective to chiral rotation has been
demonstrated. It is found that pairing correlations introduce additional
admixtures in the single-particle orbitals, and, thus, influence the structure
of tilted axis rotating nuclei by reducing the magnitude of the proton and
neutron angular momenta while merging their direction.Comment: 13 pages, 5 figure
New parametrization for the nuclear covariant energy density functional with point-coupling interaction
A new parametrization PC-PK1 for the nuclear covariant energy density
functional with nonlinear point-coupling interaction is proposed by fitting to
observables for 60 selected spherical nuclei, including the binding energies,
charge radii and empirical pairing gaps. The success of PC-PK1 is illustrated
in its description for infinite nuclear matter and finite nuclei including the
ground-state and low-lying excited states. Particularly, PC-PK1 improves the
description for isospin dependence of binding energy along either the isotopic
or the isotonic chains, which makes it more reliable for application in exotic
nuclei. The predictive power of PC-PK1 is also illustrated for the nuclear
low-lying excitation states in a five-dimensional collective Hamiltonian in
which the parameters are determined by constrained calculations for triaxial
shapes.Comment: 32 pages, 12 figures, 4 tables, accepted by Phys. Rev.
- …