The ULYSSES (UnraveLing hYpernuclear Structure and Spectroscopy ExperimentS) activity is funded by the Istituto Nazionale di Fisica Nucleare (INFN).
It consists mainly in the participation of an Italian research Group in few, selected hadronic physics experiments approved at the K1.8 beamline of the J-PARC (Japan Proton Accelerator Research Complex) Hadron Hall.
In particular the attention is focussed on hypernuclear physics measurements, with the aim of continuing the research program carried out by the FINUDA experiment.
More precisely the interest is focused on the high resolution γ-ray spectroscopy of light single Λ-hypernuclei (E13 experiment) and on the spectroscopic study of Ξ-hypernucleus $^{12}_{\ \Xi}$Be (E05 experiment, E05 web site).
The E05 (now E70) Collaboration proposed to obtain spectroscopic information on the $^{12}_{\ \Xi}$Be hypernucleus through the 12C(K-,K+) reaction, by using the high-intensity K- beam at J-PARC. Ξ-hypernuclei, whose existence is not well established so far, will be observed for the first time with enough statistics and good energy resolution as low as ~3 MeV (FWHM). In order to perform such high-resolution spectroscopy, a new K+ spectrometer will be constructed based on the existing Superconducting Kaon Spectrometer (SKS). The Ξ single-particle potential obtained from the observation of Ξ-hypernuclear states will provide not only the information on Ξ-Nucleon interaction but also insight into the high-density hadronic matter with strangeness. This experiment will represent the first step to explore multi-strangeness hadronic systems. At present, the SKS magnet has been replaced with a brand new complex of magnets nicknamed S-2S (Strangeness -2 Spectrometer). It was designed to provide an optimized angular acceptance and moreover a significantly improved energy resolution.
The E13 (now E63) Collaboration proposed to study the structure of several light Λ-hypernuclei ($^4_\Lambda$He, $^7_\Lambda$Li, $^{10}_{\ \Lambda}$B, $^{11}_{\ \Lambda}$B and $^{19}_{\ \Lambda}$F) by high-precision γ spectroscopy technique. The excited states of such hypernuclei, produced via the 1.5 GeV/c (K-,π-) reaction, will be studied by employing the K1.8 beam line and the SKS spectrometer system. γ-rays will be detect by Hyperball-J, a brand new, large Ge detector array dedicated to hypernuclear γ-ray spectroscopy at J-PARC.
In the framework of the SKS Collaboration, the Italian Group contributed as well to the E19 experiment, dedicated to high-resolution search for Θ+ pentaquark in π-p → K-X reactions, and to the E10 experiment, focused on search and study of neutron-rich Λ-hypernuclei.
