[en] Gas-filled detectors of modern experimental setups are increasingly requiring an uninterrupted gas flow with possibility of remote monitoring and control. A custom tailored and automated solution to address this issue has been designed and implemented using a single-board-embedded computer equipped with on board ADC/DAC-integrated circuits and transducer signal conditioning capabilities. The design details of system are presented in this work

[en] A further study of the FINUDA data about non-mesonic weak decay of eight Λ-hypernuclei in the A range (5–16) was carried out. New values of the ratio between the two-nucleon and the one-proton induced decay widths, Γ_2_N/Γ_p, were determined from single proton spectra, Γ_2_N/Γ_p=0.50±0.24, and from neutron and proton coincidence spectra, Γ_2_N/Γ_p=0.36±0.14_s_t_a_t _-_0_._0_4_s_y_s"+"0"."0"5"s"y"s, in full agreement with the previously published ones. Starting from these values, a method was developed to extract the one-proton induced decay width in units of the free Λ decay width, Γ_p/Γ_Λ, without resorting to Intra-Nuclear Cascade models but by exploiting measured quantities only and by assuming a linear dependence on A of the effects due to Final State Interaction. The present work is the first systematic Γ_p/Γ_Λ determination ever done and it agrees with recent theoretical predictions within the errors. (author)

[en] A new double-threshold discriminator has been designed and constructed at Frascati INFN laboratories for processing the signals arising from gas-drift chambers. Its main features are low time walk, high channel density and VME interface. The discriminator board is 9U sized and houses 32 channels mounted on independent sockets. This solution eases the replacement of faulty channels without loosing operation of the full board

[en] An array of 2424 2.6- m-long, 15- mm-diameter mylar straw tubes, arranged in two axial and four stereo layers, has been assembled at National Laboratories of Frascati of INFN for the FINUDA experiment. The array covers a cylindrical tracking surface of 18 m² and provides coordinate measurement in the drift direction and along the wire with a resolution of the order of 100 and 300 μm, respectively. The array has finished the commissioning phase and tests with cosmic rays are underway. The status straw tubes array and a very preliminary result from cosmic rays test are summarized in this work

[en] A new study of the dip observed at 1.9 GeV by the Fermilab experiment E687 in diffractive photoproduction of 3π⁺3π^- is presented. The E687 and the BABAR data on the annihilation cross-section σ(e⁺e^-→3π⁺3π^-), obtained with initial-state radiation, are fitted all together. The fit function is based on a simple mixing mechanism that explains the manifestation of a resonance as a dip. Possible interpretations in terms of hybrids and tetraquark states are considered. (orig.)

[en] The FINUDA detector is a magnetic spectrometer optimized to study hypernuclear physics at DAΦNE. The tracking part of detector contains a large cylindrical array of 2424 straws which are 2.55 m long and are required to provide a space resolution of ∝100 μm. The FINUDA straw tube detector is now in an advanced phase of construction at National Laboratories of Frascati. The straw tube detector design, structural components, and readout electronics are presented in this work. A discussion of experimental results obtained from prototypes and treatment of systematic effects, inevitably present in the case of long straw tubes, is included. (orig.)

[en] The Time Projection Chamber (TPC) is an ideal candidate to finely study the charged particle ionization in a gaseous medium. Large volume TPCs can be readout with a suitable number of channels offering a complete 3D reconstruction of a charged particle track, that is the sequence of its energy releases in the TPC gas volume. Moreover, He-based TPCs are very promising to study keV energy particles as nuclear recoils, opening the possibility for directional searches of Dark Matter (DM) and the study of Solar Neutrinos (SN). In this paper we report the analysis of the data acquired with a small TPC prototype (named LEMOn) built by the CYGNO collaboration that was exposed to a beam of 450 MeV electrons at the Beam Test Facility of National Laboratories of Frascati. LEMOn is operated with a He-C${\mathrm{F}}_4$ mixture at atmospheric pressure and is based on a Gas Electron Multipliers amplification stage that produces visible light collected by the high granularity and very good sensitivity of scientific CMOS camera. This type of readout – in conjunction with a fast light detection – allows a 3D reconstruction of the electrons tracks. The electrons are leaving a trail of clusters of ionizations corresponding to a few keV energy release each. Their study leads to predict a keV energy threshold and 1–10 mm longitudinal and 0.1–0.3 mm transverse position resolution (sigma) for nuclear recoils, very promising for the application of optically read out TPC to DM searches and SN measurements.

[en] A 9U VME like double threshold discriminator has been designed and constructed at Frascati INFN (National Institute of Nuclear Physics) laboratories. Its aim is to process the signals arising from gas drift chambers, introducing a very small time walk (∼ 650 ps.). Each discriminator board houses 32 channels. Each channel is located on an independent printed circuit mounted on socket. This solution is very convenient for replacing faulty channels without loosing operation of the full board

[en] We present a study of the characteristics of a hybrid image intensifier tube based on a thinned backside Electron Bombarded CCD (EBCCD) with better performance in spatial resolution, single photoelectron detection and gain stability than the conventional intensified systems based on a Micro Channel Plate followed by a CCD. Single photon detection sensitivity has been studied and a procedure to correct the gain non-uniformity of the EBCCD has been developed. The EBCCD, operating at 14 kV, has an average gain of ∼3000 electrons/photoelectron and a noise of the order of 100 electron/pixel. These characteristics make the EBCCD a very attractive device for many applications in high-energy physics, astrophysics and biomedicine. A possible application in a neutrino oscillation experiment is presented

[en] Momenta spectra of protons emitted following the capture of K^- in ⁶Li and ¹²C have been measured with 1% resolution. The ¹²C spectrum is smooth whereas for ⁶Li a well defined peak appears at about 500 MeV/c. The first observation of a structure in this region was identified as a strange tribaryon or, possibly, a K-bar -nuclear state. The peak is correlated with a π^- coming from Σ^- decay in flight, selected by setting the π momentum larger than 275 MeV/c. The Σ^- could be produced, together with a 500 MeV/c proton, by the capture of a K^- in a deuteron-cluster substructure of the ⁶Li nucleus. The capture rate for such a reaction is (1.62+/-0.23_stat-0.44^+0.71(sys))%/K_stop^-, in agreement with the existing observations on ⁴He targets and with the hypothesis that the ⁶Li nucleus can be interpreted as a (d+α) cluster