11 research outputs found
Renormalization of the one-body off-diagonal Coulomb field in nuclei
Isospin violation effects in nuclei are investigated within a microscopic
approach which takes into account the influence of the residual strong
interaction on the Coulomb interaction. The renormalization of the off-diagonal
Coulomb field acting within a nucleus, by the residual strong interaction is
calculated analytically in a simplified RPA. From the expression for the
suppression coefficient of the isospin violating part of the Coulomb field, the
isospin violating spreading widths of isobaric analog states are derived. The
resulting reduction of the width is in agreement with the data on the isospin
symmetry restoration and with some earlier evaluations of the isospin violating
spreading widths.Comment: 11 pages, Late
SU(2,1) Dynamics of Multiple Giant Dipole Resonance Coulomb Excitation
We construct a three-dimensional analytically soluble model of the nonlinear
effects in Coulomb excitation of multiphonon Giant Dipole Resonances (GDR)
based on the SU(2,1) algebra. The full 3-dimensional model predicts further
enhancement of the Double GDR (DGDR) cross sections at high bombarding
energies. Enhancement factors for DGDR measured in thirteen different processes
with various projectiles and targets at different bombarding energies are well
reproduced with the same value of the nonlinearity parameter with the exception
of the anomalous case of Xe which requires a larger value.Comment: 10 pages, 3 Postscript figures, late
Structure of Low-Energy Collective -States in Doubly Magic Nuclei and Matrix Elements of the P-odd and P- and T-odd Weak Interaction
The structure of the collective low-energy (T=0 and T=1)
modes is studied for a doubly magic nucleus in a schematic analytic model of
RPA. The phonon states () lie at energies E_{T=0}(0^{-}) \alt
\omega and , where is the oscillator
frequency. The matrix elements of P-odd and P- and T-odd weak one-body
potentials connecting the ground state to these -states, , are
enhanced by the factor as
compared to the single-particle value what can result in values
if standard values of DDH parameters are used for
. Similar enhancement arises in the P- and T-odd case.Comment: 15 pages, REVTEX 3, 2 figure
Anomalous anapole moment of an exotic nucleus
Using the information on the nuclear structure of exotic neutron-rich halo
nucleus Be, we evaluate the parity violating anapole moment in its
ground state. The resulting value Be) is fifteen times
bigger than the typical value of the anapole moment of a normal nucleus of the
same mass, and in fact exceeds by few times anapole moments of any known
neutron-odd nuclei (e.g., kappa(^{11}Be) > 2|\kappa(^{207}Pb)|. It is also few
times bigger than the neutral current contribution to the lepton-nucleus
interaction.Comment: 12 pages, 2 figure
Problem of a quantum particle in a random potential on a line revisited
The density of states for a particle moving in a random potential with a
Gaussian correlator is calculated exactly using the functional integral
technique. It is achieved by expressing the functional degrees of freedom in
terms of the spectral variables and the parameters of isospectral
transformations of the potential. These transformations are given explicitly by
the flows of the Korteweg-de Vries hierarchy which deform the potential leaving
all its spectral properties invariant. Making use of conservation laws reduces
the initial Feynman integral to a combination of quadratures which can be
readily calculated. Different formulations of the problem are analyzed.Comment: 11 pages, RevTex, preprint ANU-RSPhySE-20994 (comment added
Limits of Time-Reversal Violating Interaction from Compound Nuclear Experiments
Mean square matrix elements of the time reversal invariance violating (TRIV)
interaction between the compound nuclear states are calculated within the
statistical model, using the explicit form of the TRIV interaction via the
-meson exchange. From the comparison of the calculated values with the
data known for reaction, and for
-correlation measurements in process, the
bounds on the TRIV constant are obtained {\bar g}_{\rho} \alt 1.8 \times
10^{-2} and {\bar g}_{\rho} \alt 1.1 \times 10^{-2}. The sensitivity of the
recently proposed detailed balance test experiments on isolated resonances in
to the value of is shown to be as high as to reach
values .Comment: Phys. Lett. B; to be published, 16 pages, REVTEX 3, no figure