670 research outputs found
Missing levels in correlated spectra
Complete spectroscopy (measurements of a complete sequence of consecutive
levels) is often considered as a prerequisite to extract fluctuation properties
of spectra. It is shown how this goal can be achieved even if only a fraction
of levels are observed. The case of levels behaving as eigenvalues of random
matrices, of current interest in nuclear physics, is worked out in detail.Comment: 14 pages and two figure
Evaluation of Effective Astrophysical S factor for Non-Resonant Reactions
We derived analytic formulas of the effective S astrophysical S factor,S^eff
for a non-resonant reaction of charged particles using a Taylor expension of
the astrophysical S factor and a uniform approximation.The formulas will be
able to generate generate more accurate approximation to S^eff than previous
ones
Structure of trajectories of complex matrix eigenvalues in the Hermitian-non-Hermitian transition
The statistical properties of trajectories of eigenvalues of Gaussian complex
matrices whose Hermitian condition is progressively broken are investigated. It
is shown how the ordering on the real axis of the real eigenvalues is reflected
in the structure of the trajectories and also in the final distribution of the
eigenvalues in the complex plane.Comment: 12 pages, 3 figure
Causal Classical Theory of Radiation Damping
It is shown how initial conditions can be appropriately defined for the
integration of Lorentz-Dirac equations of motion. The integration is performed
\QTR{it}{forward} in time. The theory is applied to the case of the motion of
an electron in an intense laser pulse, relevant to nonlinear Compton
scattering.Comment: 8 pages, 2 figure
Addendum: Attenuation of the intensity within a superdeformed band
We investigate a random matrix model [Phys. Rev. C {\bf 65} 024302 (2002] for
the decay-out of a superdeformed band as a function of the parameters:
, , and . Here
is the spreading width for the mixing of an SD state
with a normally deformed (ND) doorway state , and
are the electromagnetic widths of the the SD and ND states respectively, is
the mean level spacing of the compound ND states and is the energy
difference between and . The maximum possible effect of an
order-chaos transition is inferred from analytical and numerical calculations
of the decay intensity in the limiting cases for which the ND states obey
Poisson and GOE statistics. Our results show that the sharp attenuation of the
decay intensity cannot be explained solely by an order-chaos transition.Comment: 4 pages, 4 figures, submitted to Physical Review
- …