Search

In recent years, several experiments using magnetic spectrometers provided high precision results in the field of Hypernuclear Physics. In particular, the accurate determination of the Lambda-binding energy, B(Lambda), contributed to stimulate considerably the discussion about the Charge Symmetry Breaking effect in Lambda-hypernuclei isomultiplets. We have reorganized the results from the FINUDA experiment and we have obtained a series of B(Lambda) values for Lambda-hypernuclei with A, Comment: 22 pages, 5 figures

Recent results reported by experiments with relativistic (heavy) ions have raised again the question whether the lifetime of H Λ 3 is very close to the lifetime of the free Λ hyperon. An updated careful analysis of all the existing experimental data shows that it is not, contrary to theoretical calculations. A similar conclusion can be drawn for the neighbor H Λ 4 . A clear cut high precision measurement performed with the straightforward method of time delay spectra is however lacking and it is eagerly needed. The idea of using the ( π − , K 0 ) charge-exchange associated production reaction on targets of liquid 3,4 He is discussed. A possible realization exploiting a large part of existing facilities at J-PARC is presented. A measurement with a 5% precision seems within reach with a modest effort and in a reasonable amount of time. The same set-up would also serve very well for the measurement of the lifetime of several neutron-rich Λ-hypernuclei of the p -shell, in particular of B Λ 12 . More importantly, the Weak Decay partial widths Γ π − , Γ p and Γ π 0 could be simultaneously determined in order to confirm their predicted strong variation with mass number, A, due to nuclear structure effects.

An experimental study of the ${K}_{\mathrm{stop}}^{\ensuremath{-}}A\ensuremath{\rightarrow}{\mathrm{\ensuremath{\Sigma}}}^{\ensuremath{-}}p{A}^{\ensuremath{'}}$ reaction on $A=^{6}\mathrm{Li},\phantom{\rule{0.16em}{0ex}}^{7}\mathrm{Li},\phantom{\rule{0.16em}{0ex}}^{9}\mathrm{Be},\phantom{\rule{0.16em}{0ex}}^{13}\mathrm{C}$, and $^{16}\mathrm{O}\phantom{\rule{4pt}{0ex}}p$-shell nuclei is presented. The data were collected by the FINUDA spectrometer operating at the $\mathrm{DA}\mathrm{\ensuremath{\Phi}}\mathrm{NE}\phantom{\rule{4pt}{0ex}}\ensuremath{\phi}$ factory (LNF-INFN, Italy). Emission rates for the reaction in the mentioned nuclei are measured and compared with the few existing data. The spectra of several observables are discussed; indications of quasifree absorptions by a $(np)$ pair embedded in the $A$ nucleus can be obtained from the study of the missing mass distributions.