[en] Recent experimental results on pion production in different channels leading to a 3-body final state (pp → pnπ⁺, pp → ppπ⁰, np → ppπ^-) are reviewed. New data in the η production channel are presented. In the two cases results are compared to calculations either in a coupled channel calculation or in a first order perturbative approach. The role of NΔ and NN^* mechanisms are pointed out. (K.A.). 33 refs., 20 figs

[en] New results of (p,π) reaction on light target nuclei (³He, ⁴He, ⁶Li, ¹⁰B) have been obtained at IPN Orsay. Data on (³He,π⁺) reaction on the same targets, in the exclusive kinematical region are presented together with data on ⁶Li(d,π^-)⁸B reaction obtained at Saturne

[en] A general overview about the properties of Cathode Strip and Pad Chambers is given. Position finding methods are discussed and compared within Monte Carlo studies. Noise contributions and their minimization are discussed. Pad chambers allow a two-dimensional readout with spatial resolution of σ < 100 μm in direction parallel to the anode wire. The resolution normal to the anode wire depends mainly on the wire spacing. Special attention is paid on the double-hit resolution capability of the pad chamber. An outlook is given on the possible utilisation of Cathode Pad Chambers in the Di-Muon Arm of the ALICE detector at LHC. (author)

[en] The experimental evidence for narrow dibaryons has an essential importance if it can be associated to quark degrees of freedom in nuclei. The difficulty is double: first the corresponding structures have to be observed. Second when observed these structures have to be dissociated as much as possible from any classical explanation as for example a threshold effect corresponding to the opening of a new channel of mesons and two baryons in interaction. Extensive researches are done in some laboratories with emphasizes on the accuracy of the data: only such data, achieved in the two last years will be presented here. The solution of the first difficulty needs data of high precision, both statistical and systematic. The second point: the identification of data with quark degrees of freedom is before all a theoretical problem although it will be clearly favoured by the narrowness of the observed dibaryons. In opposition to experimental investigations for T = 1 and T = 2 dibaryons, where many experiments have been accomplished, there have been no data concerning pure isoscalar dibaryon search. Experimentally evidence for isovector dibaryons has been strengthened, especially in the range above M = 2 M_N + M_π. Intensive works are presently carried out below this threshold. There is still no signature in the isoscalar dibaryon sector. Different experiments have been accomplished in the search of T = 2 narrow dibaryons, at Saturne, Triumf and Lampf, but in any case a narrow structure has been observed

[en] Experimental evidence for narrow structures at well defined masses in the T = 1 dibaryon sector is discussed. The evidence is not strong enough for the T = 0 or 2 dibaryons and for tribaryons. Experimental requirements needed in order to better understand the structures, e.g., angular distributions for excited T1 baryons and experiments in pure T = 0, 2, and 3 states and in the tribaryon sector, are summarized. Theoretical studies are needed to specify masses and widths of multibaryonic states, as well as dynamical calculations of the relative size of the multibaryon signal and of the background to explain why the structures appear for different reactions and incident energies. Narrow structures are really observed. Their identification with quark degrees of freedom remains the simplest explanation

[en] A few topics of narrow structures in nuclear physics at excitation energies of several hundred MeV are overviewed. Among these topics, the physics of dibaryons is particularly interesting since if narrow structures are observed, they can be related to precursor partial quark deconfinement. This possibility simulated the large number of data corresponding to such studies. A brief literature survey of these studies is given. The studies and recent data included in this overview are: analyzing powers in nucleon-nucleon elastic scattering, the p(d,pp)X reaction (X being the two proton missing masses), the ²H(p,n)X⁺⁺ reaction, and dibaryon searches from photonuclear reactions. (R.P.) 39 refs., 6 figs

[en] The results of recently performed experiments on the B=2 structures concerning the 0,1 and 2 isospin different states are presented. Experimental data and theoretical models are considered. In the T=1 channel, the existence of narrow states, above the πNN threshold, is established. The results from T=0.2 channels are quite difficult to analyse. Present calculations do not allow the prediction of which of the observables are affected by such structures

[en] The experimental situation concerning the hunting of narrow non strange dibaryons is presented and discussed. These have not been firmly observed, up to now, in isospin T = 0 and T = 2 channels, contrary to the situation in T = 1 channel where the existence of such dibaryons is now experimentally well established

[en] New results of (p,π) reaction on light target nuclei (³He, ⁴He, ⁶Li, ¹⁰B) have been obtained at IPN Orsay. Data on (³He,π⁺) reaction on the same targets, in the exclusive kinematical region are presented together with data on ⁶Li(d,π^-)⁸B reaction obtained at Saturne

[en] The energy dependence of the ⁶Li(³He,π⁺)⁹Be(g.s.) reaction at theta lab = 20⁰ has been studied for Tsub(3He)=235, 260, 270 and 283 MeV and at 40⁰ and 55⁰ for 235 and 283 MeV. A semi-phenomenological model reproduces the shape of the angular distribution and the order of magnitude of the cross section but predicts a too sharp energy variation. Experimental results on ¹⁰B(³He,π⁺)¹³C(g.s.) at 20⁰ lab for 260 and 283 MeV are of a similar size