15 research outputs found
Subleading contributions to the width of the D_{s0}*(2317)
We construct the effective chiral Lagrangian involving the
D--mesons and Goldstone bosons at next-to-leading order taking into account
strong as well as electromagnetic interactions. This allows us to disentangle
-- to leading order in isospin violation -- the electromagnetic and the strong
contribution to the D--meson mass differences. In addition, we also apply the
interaction to the decay D_{s0}^*(2317)-> D_s pi0 under the assumption that the
D_{s0}^*(2317) is a hadronic molecule. We find (180+-110) keV for the decay
width $\Gamma (D_{s0}^*(2317)-> D_s pi0) -- consistent with currently existing
experimental constraints as well as previous theoretical investigations. The
result provides further evidence that this decay width can serve as a criterion
for testing the nature of the D_{s0}^*(2317).Comment: 11 pages, 2 figure
Microscopic nature of the photon strength function: stable and unstable Ni and Sn isotopes
The pygmy-dipole resonances and photon strength functions in stable and
unstable Ni and Sn isotopes are calculated within the microscopic
self-consistent version of the extended theory of finite fermi systems which
includes the QRPA and phonon coupling effects and uses the known Skyrme forces
SLy4. The pygmy dipole resonance in is predicted with the mean energy
of 12.4 MeV and the energy-weighted sum rule exhausting 25.6\% of the total
strength. The microscopically obtained photon E1 strength functions are used to
calculate nuclear reaction properties, i.e the radiative neutron capture cross
section, gamma-ray spectra, and average radiative widths. Our main conclusion
is that in all these quantities it is necessary to take the phonon coupling
effects into account.Comment: 4 pages, 5 figures, 2 tables. Talk at 15-th International Symposium
on Capture Gamma-Ray Spectroscopy and Related Topics (CGS15), Dresden, August
2o1
Impact of the phonon coupling on the photon strength function
The pygmy dipole resonances and photon strength functions in stable and
unstable Ni and Sn isotopes are calculated within the microscopic
self-consistent version of the extended theory of finite fermi systems which
includes phonon coupling effects.The Skyrme forces SLy4 is used. A pygmy dipole
resonance in Ni is predicted at the mean energy of 12.4 MeV exhausting
25.7\% of the total energy-weighted sum rule. The microscopically obtained
photon E1 strength functions are compared with available experimental data and
used to calculate nuclear reaction properties. Average radiative widths and
radiative neutron capture cross sections have been calculated taking the phonon
coupling into account as well as the uncertainties caused by various
microscopic level density models. In all three quantities considered, the
contribution of phonon coupling turned out to be significant and is found
necessary to explain available experimental data.Comment: 4 pages, 3 figures Submitted to Phys. Rev.
Hadronic-loop induced mass shifts in scalar heavy-light mesons
We calculate the mass shifts of heavy-light scalar mesons due to hadronic
loops under the assumption that these vanish for the groundstate heavy-light
mesons. The results show that the masses calculated in quark models can be
reduced significantly. We stress that the mass alone is not a signal for a
molecular interpretation. Both the resulting mass and the width suggest the
observed state could be a dressed state. We give further
predictions for the bottom scalar mesons which can be used to test the dressing
mechanism.Comment: 14 pages, 2 figures. Version accepted for publication in Phys. Lett.
Group Theory
1. Motivation: symmetries and groups in physics2. Finite groups3. Representation theory4. Point groups and applications in physics5. Continuous group