273 research outputs found
Exotic atoms and exotic nuclei
We briefly review the study of the exotic atoms and exotic nuclei, and report
recent research activities of eta-mesic nucleus and kaonic atoms in this
article.Comment: 6 pages, 2 figures. Talk given at II Symposium on applied nuclear
physics and innovative technologies, Jagiellonian University, Krakow, Poland,
Acta Physica Polonica B (2015) in pres
eta-prime nucleus optical potential and possible eta-prime bound states
Starting from a recent model of the eta'N interaction, we evaluate the
eta'-nucleus optical potential, including the contribution of lowest order in
density, t rho/2m_eta', together with the second order terms accounting for
eta' absorption by two nucleons. We also calculate the formation cross section
of the eta' bound states from (pi+,p) reactions on nuclei. The eta'-nucleus
potential suffers from uncertainties tied to the poorly known eta'N
interaction, which can be partially constrained by the experimental modulus of
the eta'N scattering length and/or the recently measured transparency ratios in
eta' nuclear photoproduction. Assuming an attractive interaction and taking the
claimed experimental value |a_eta'N| = 0.1 fm, we obtain a eta' optical
potential in nuclear matter at saturation density of V_eta' = -(8.7 + 1.8i)
MeV, not attractive enough to produce eta' bound states in light nuclei. Larger
values of the scattering length give rise to deeper optical potentials, with
moderate enough imaginary parts. For a value |a_eta'| = 0.3 fm, which can still
be considered to lie within the uncertainties of the experimental constraints,
the spectra of light and medium nuclei show clear structures associated to
eta'-nuclear bound states and to threshold enhancements in the unbound region.Comment: 11 pages, 4 figures, 2 table
In--Flight () Reactions for the Formation of Kaonic Atoms and Kaonic Nuclei in Green function method
We study theoretically the kaonic atom and kaonic nucleus formations in the
in--flight () reactions using the Green function method, which is suited
to evaluate formation rates both of stable and unstable bound systems. We
consider C and O as the targets and calculate the spectra of the
() reactions. We conclude that a no peak structure due to kaonic nucleus
formation is expected in the reaction spectra calculated with the chiral
unitary kaon--nucleus optical potential. In the spectra with the
phenomenological deep kaon--nucleus potential, we may have possibilities to
observe some structures due to kaonic nucleus states. For all cases, we have
peaks due to the kaonic atom formations in the reaction spectra.Comment: 10 pages, 9 figures, newly calculated results added, revisions and
updated references, to appear in Physical Review
Formation of \eta'(958)-mesic nuclei and axial U_A(1) anomaly at finite density
We discuss the possibility to produce the bound states of the
meson in nuclei theoretically. We calculate the formation cross sections of the
bound states with the Green function method for (,p) reaction
and discuss the experimental feasibility at photon facilities like SPring-8. We
conclude that we can expect to observe resonance peaks in (,p) spectra
for the formation of bound states and we can deduce new information on
properties at finite density. These observations are believed to be
essential to know the possible mass shift of and deduce new information
of the effective restoration of the chiral anomaly in the nuclear
medium.Comment: 4 pages, 3 figure
Formation of Heavy Meson Bound States by Two Nucleon Pick-up Reactions
We develop a model to evaluate the formation rate of the heavy mesic nuclei
in the two nucleon pick-up reactions, and apply it to the Li target cases
for the formation of heavy meson- bound states, as examples. The
existence of the quasi-deuteron in the target nucleus is assumed in this model.
It is found that the mesic nuclei formation in the recoilless kinematics is
possible even for heavier mesons than nucleon in the two nucleon pick-up
reactions. We find the formation rate of the meson- bound states can be
around half of the elementary cross sections at the recoilless kinematics with
small distortions.Comment: 1 table, 10 figures, 8 page
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