3 research outputs found
Branching ratio change in K- absorption at rest and the nature of the Lambda(1405)
We investigate in-medium corrections to the branching ratio in K- absorption
at rest and their effect on the (positively and negatively) charged pion
spectrum. The in-medium corrections are due to Pauli blocking, which arises if
the Lambda(1405) is assumed to be a -nucleon bound state and leads to
a density and momentum dependent mass shift of the Lambda(1405). Requiring that
the optical potential as well as the branching ratio are derived from the same
elementary T-matrix, we find that the in-medium corrected, density dependent
T-matrix gives a better description of the K- absorption reaction than the
free, density-independent one. This result suggests that the dominant component
of the Lambda(1405) wave function is the bound state.Comment: 8 Pages, Revtex with epsf, and embedded 8 ps figure
The reaction on p-shell nuclei
This letter is concerned with the study of the reaction in p-shell nuclei, i.e., , ,
and . The emission rates are
reported as a function of . These rates are discussed in comparison with
previous findings. The ratio in p-shell nuclei is
found to depart largely from that on hydrogen, which provides support for large
in-medium effects possibly generated by the sub-threshold . The
continuum momentum spectra of prompt pions and free sigmas are also discussed
as well as the missing mass behavior and the link with the
reaction mechanism. The apparatus used for the investigation is the FINUDA
spectrometer operating at the DANE -factory (LNF-INFN, Italy).Comment: 14 pages, 5 figures, accepted for publication in Phys. Lett.