[en] The production of π⁰ and η mesons in the reactions pd #-> # ³Heπ^o and pd #-> #³Heη has been studied at very backward angles for proton kinetic energies ranging from 0.92 to 2.6 GeV. The ³He produced in these experiments were detected with the SPES 4 spectrometer at the Laboratoire National Saturne. The η production cross-sections are close to those of π^o production and are even larger at high energy. The excitation functions for θ_π,η=180 deg (cm) display broad structures. Our results have been compared to several theoretical models. None of them gives a satisfying description of the experimental data. It is qualitatively shown that the observed structures might be related to baryonic excitations (N*) which could be due to an η meson exchange in the intermediate state

[en] Elastic pd and p³He backward scattering have been measured in the kinetic energy range 0.6< Tsub(p)<2.7 GeV on deuterium target 0.7< Tsub(p)<1.7 GeV on helium-3 target. The pd → Tπ reaction (at thetasub(π) = 180⁰) has been also studied from 0.6 to 1.5 GeV. New structures have been observed in the excitation functions of the three reactions; they could be due to the excitation of isobaric resonances in the intermediate state. A phenomenological analysis of the results leads to privilege exchange mechanisms in such reactions

[en] The production of π⁰ and eta⁰ mesons in the reactions pd→π⁰tau and pd→eta⁰tau has been studied at very backward angles for kinetic proton energies Tsub(p) ranging from 0.92 to 2.6 GeV. The excitation functions at phisub(π) = phisub(eta) = 180⁰ display large structures which might be related to baryonic (Δ and N*) excitations in the intermediate state

[en] Missing mass spectra from ³He(p,d)X at Tsub(p)=.75 GeV (thetasub(lab) = 22⁰, 32⁰ and 40⁰) and Tsub(p) = .925 GeV (thetasub(lab) = 30⁰, 40⁰) have been measured. Missing mass spectra from p(³He, d)X at T₃sub(He) = 2.7 GeV and thetasub(lab)=18⁰ have also been measured. The experiments have been carried out with a high missing mass resolution in order to detect possible narrow structures associated with B=2, T=1 quantum numbers. Such structures have been found whose masses and withs are given in the text. The masses of the narrow structures are shown to agree with a rotational like mass formula M=M₀ + M₁ J(J+1), J being the associated spin. The observed peaks might be related to six quark states

[en] A search for isoscalar dibaryonic resonances by means of missing mass spectra in the d + d → d + X reaction has been attempted using deuteron beams of T = 2.29, 2.00 and 1.65 GeV. The results do not show any evidence for a narrow peak with a limit of 0.03 pb/MeV² for a 15 MeV width or a broad enhancement which could be unambiguously attributed to a dibaryonic resonance.

[en] We present a detailed study on the effect of strontium non-stoichiometry on the properties of double perovskite Sr_2FeMoO_6 (SFMO). A citrate route has been used to prepare high quality polycrystalline samples with (2−x)Sr:Fe:Mo (x=0, 0.02, 0.04) and (2+x)Sr:Fe:Mo (x=0.02, 0.04, 0.10) cationic ratios. The strontium deficient samples exhibit a significant decrease in their values of saturation magnetization (Ms), Curie temperature (Tc) and magnetoresistance (MR) compared to the stoichiometric SFMO. On the other hand, the samples prepared with an excess of strontium, respectively those with x=0.02 and 0.04, show remarkably superior magneto–transport characteristics, despite of their increased level of Fe/Mo disorder and somewhat diminished magnetic properties compared to the stoichiometric SFMO. We also show that these samples exhibit superior MR values under low magnetic field and persisting up to temperatures as high as 400 K. - Graphical abstract: Evolution of the magnetization versus temperature under an applied magnetic field of 1000 Oe (left panel) and magnetoresistance versus applied magnetic field at 300 K (right panel) for strontium off-stoichiometric Sr_2FeMoO_6 samples. - Highlights: • Strontium nonstoichiometric samples of Sr_2FeMoO_6 are prepared by a citrate route. • The nonstoichiometric samples exhibit an increased Fe/Mo disorder in the structure. • We observed important changes in their magnetic and magnetoresistive properties. • Improved magnetoresistive properties for samples prepared with strontium excess

[en] Elastic pd backward scattering in the kinetic energy range 0.6 < Tsub(p) < 2.7 GeV has been measured and is discussed in terms of the one nucleon exchange (ONE) and the one pion exchange (OPE) mechanisms. The experimental plateau appearing in the 180⁰ excitation function for Tsub(p)>2. GeV could be explained as excitation of the Δ(1950) in the intermediate state

[en] The π⁰ detector with 4π solid angle is described; the technical problems and its characteristics are presented. The existing π⁰ detectors are reviewed

[en] The inclusive inelastic scattering of α particles on ²H, ³He, and ⁴He has been measured at 7.0 GeV/c incident momentum, between 2⁰ and 15⁰ in the laboratory. The momentum spectra of the recoiling α particles are richly structured, suggesting that scattering takes place, at least partially, on nuclear substructures. The differential cross sections for the three reactions show a diffractive behavior comparable to that of the corresponding elastic processes

[en] The missing-mass spectra for the transfer reactions p( ³He, d)X and ³He(p,d)X (B = 2, T = 1) have been measured at, respectively, T3He = 2.7 GeV and T/sub p/ = 0.925 GeV. The data show a narrow structure lying on top of an important continuum, with a mass M = 2.240 +- 0.005 GeV and a width GAMMA/sub 1/2/ = 0.016 +- 0.003 GeV