arXiv subjects

FINUDA Collaboration

Publications and source records attributed to FINUDA Collaboration.

5 recordsLinked to original sources

arXiv2015

$\Sigma^- p$ emission rates in $K^-$ absorptions at rest on $^6$Li, $^7$Li, $^{9}$Be, $^{13}$C and $^{16}$O

An experimental study of the $K^-_{stop}A\rightarrow \Sigma^- p A'$ reaction on $A=^6$Li, $^7$Li, $^9$Be, $^{13}$C and $^{16}$O $p$-shell nuclei is presented. The data were collected by the FINUDA spectrometer operating at the DA$\Phi$NE $\phi$-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 Quasi-Free absorptions by a $(np)$ pair embedded in the $A$ nucleus can be obtained from the study of the missing mass distributions.

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arXiv2011

The $A(K^-_{stop},\pi^\pm\Sigma^\mp)A'$ reaction on p-shell nuclei

This letter is concerned with the study of the $K^-_{stop}A\rightarrow \pi^\pm\Sigma^\mp A'$ reaction in p-shell nuclei, i.e., $^{6,7}Li$, $^9Be$, $^{13}C$ and $^{16}O$. The $\pi^\pm\Sigma^\mp / K^-_{stop}$ emission rates are reported as a function of $A$. These rates are discussed in comparison with previous findings. The ratio $\pi^-\Sigma^+/\pi^+\Sigma^-$ 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 $\Lambda(1405)$. The continuum momentum spectra of prompt pions and free sigmas are also discussed as well as the $\pi^\pm\Sigma^\mp$ missing mass behavior and the link with the reaction mechanism. The apparatus used for the investigation is the FINUDA spectrometer operating at the DA$\Phi$NE $\phi$-factory (LNF-INFN, Italy).

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arXiv2010

Hypernuclear spectroscopy with K$^-$ at rest on $^7$Li, $^9$Be, $^{13}$C and $^{16}$O

The FINUDA experiment collected data to study the production of hypernuclei on different nuclear targets. The hypernucleus formation occurred through the strangeness-exchange reaction $K^-_{stop} + \; ^AZ \rightarrow \; ^A_{\Lambda}Z + \pi^-$. From the analysis of the momentum of the emerging $\pi^-$, binding energies and formation probabilities of $^7_{\Lambda}$Li, $^9_{\Lambda}$Be, $^{13}_{\Lambda}$C and $^{16}_{\Lambda}$O have been measured and are here presented. The behavior of the formation probability as a function of the atomic mass number A is also discussed.

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arXiv2010

Study of some two-body non-mesonic decays of $^4_\Lambda$He and $^5_\Lambda$He

The Non-Mesonic (NM) decay of $^4_\Lambda{\mathrm{He}}$ and $^5_\Lambda{\mathrm{He}}$ in two-body channels has been studied by the FINUDA Collaboration. Two-body NM decays of hypernuclei are rare and the existing observations and theoretical calculations are scarce. The $^4_\Lambda{\mathrm{He}}\rightarrow d+d,\; p+t$ decay channels simultaneously observed by FINUDA on several nuclei are compared: the $pt$ channel is the dominant one. The decay yields for the two decay channels are assessed for the first time: they are $(1.37\pm 0.37)\times 10^{-5}/K^-_{stop}$ and $(8.3\pm 1.0)\times 10^{-5}/K^-_{stop}$, respectively. Due to the capability of FINUDA of identifying $^5_\Lambda{\mathrm{He}}$ hypernuclei, a few $^5_\Lambda{\mathrm{He}}\rightarrow d+t$ decay events have also been observed. The branching ratio for this decay channel has been measured for the first time: $(3.0\pm 2.3)\times 10^{-3}$.

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arXiv2005

First Results on 12Lambda-C production at DAPHNE

Lambda-hypernuclei are produced and studied, with the FINUDA spectrometer, for the first time at an e+e- collider: DAPHNE, the Frascati phi-factory. The slow negative kaons from phi(1020) decay are stopped in thin (0.2 g/cm^2) nuclear targets, and Lambda-hypernuclei formation is detected by measuring the momentum of the outgoing pi^-. A preliminary analysis on 12Lambda-C shows an energy resolution of 1.29 MeV FWHM on the hypernuclear levels, the best obtained so far with magnetic spectrometers at hadron facilities. Capture rates for the ground state and the excited ones are reported, and compared with previous experiments.

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