202 research outputs found
Recent topics of mesic atoms and mesic nuclei -- mesic nuclei exist ?--
We study -meson production in nuclei to investigate the in-medium
modification of the -meson spectral function at finite density. We
consider (), () and () reactions to produce a
-meson inside the nucleus and evaluate the effects of the medium
modifications to reaction cross sections. The structures of the bound states,
-mesic nuclei, are also studied. For strong absorptive interaction cases,
we need to know the spectrum shape in a wide energy region to deduce the
properties of .Comment: Talk given at EXA08, Vienna, September 2008. To be published in the
Proceedings, Hyperfine Interactions. 6 pages, 6 figure
Residual interaction effects on deeply bound pionic states in Sn and Pb isotopes
We have studied the residual interaction effects theoretically on the deeply
bound pionic states in Pb and Sn isotopes. We need to evaluate the residual
interaction effects carefully in order to deduce the nuclear medium effects for
pion properties, which are believed to provide valuable information on nuclear
chiral dynamics. The s- and p-wave interactions are used for the
pion-nucleon residual interactions. We show that the complex energy shifts are
around [(10-20)+i(2-7)]keV for 1s states in Sn, which should be taken into
account in the analyses of the high precision data of deeply bound pionic
states in Sn isotopes.Comment: REVTEX4, 6 pages, 5 tables, Submitted to Phys. Rev. C, Some
explanations are added in Version
Coupling vector and pseudoscalar mesons to study baryon resonances
A study of meson-baryon systems with total strangeness -1 is made within a
framework based on the chiral and hidden local symmetries. These systems
consist of octet baryons, pseudoscalar and vector mesons. The pseudoscalar
meson-baryon (PB) dynamics has been earlier found determinant for the existence
of some strangeness -1 resonances, for example, ,
, etc. The motivation of the present work is to study the effect
of coupling the closed vector meson-baryon (VB) channels to these resonances.
To do this, we obtain the and
amplitudes from the t-channel diagrams and the
amplitudes are calculated using the Kroll-Ruddermann term where, considering
the vector meson dominance phenomena, the photon is replaced by a vector meson.
The calculations done within this formalism reveal a very strong coupling of
the VB channels to the and . In the isospin 1
case, we find an evidence for a double pole structure of the
which, like the isospin 0 resonances, is also found to couple strongly to the
VB channels. The strong coupling of these low-lying resonances to the VB
channels can have important implications on certain reactions producing them.Comment: Minor typos corrected (in Eq.(22) and axis-labels of some figures
Formation of Deeply Bound Kaonic Atoms in (K^-,N) Reactions
We study theoretically the (K^-,N) reactions for the formation of the deeply
bound kaonic atoms, which were predicted to be quasi--stable with narrow
widths, using the Green function method. We consider various cases with
different target nuclei and energies systematically and find the clear signals
in the theoretical spectra for all cases considered in this article. The
signals show very interesting structures, such as the instead
of the resonance peak. We discuss the origins of the interesting structures and
possibilities to get new information on the existence of the kaonic nuclei from
the spectra of the atomic state formations.Comment: 11 pages, 9 figure
- …