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Positive baryon numbers (A>0) and positive lepton numbers (L>0) characterize matter particles while negative baryon numbers and negative lepton numbers characterize antimatter particles. Matter particles and antimatter particles belong to two distinct classes of particles. Matter neutral particles are particles characterized by both zero baryon number and zero lepton number. This third class of particles includes mesons formed by a quark and an antiquark pair (a pair of matter particle and antimatter particle) and bosons which are messengers of known interactions (photons for electromagnetism, W and Z bosons for the weak interaction, gluons for the strong interaction). The antiparticle of a matter particle belongs to the class of antimatter particles, the antiparticle of an antimatter particle belongs to the class of matter particles. The antiparticle of a matter neutral particle belongs to the same class of matter neutral particles. A truly neutral particle is a particle identical with its antiparticle; it belongs necessarily to the class of matter neutral particles. All known interactions of the Standard Model conserve baryon number and lepton number; matter cannot be created or destroyed via a reaction governed by these interactions. Conservation of baryon and lepton number parallels conservation of atoms in chemistry; the number of atoms of a particular species in the reactants must equal the number of those atoms in the products. These laws of conservation valid for interaction involving matter particles are indeed valid for any particles (matter particles characterized by positive numbers, antimatter particles characterized by negative numbers, and matter neutral particles characterized by zero). Interactions within the framework of the Standard Model which conserve both matter and charge at the microscopic level cannot explain the observed asymmetry of our Universe. The strong interaction was introduced to explain the stability of nuclei: there must exist a powerful force to compensate the electromagnetic force which tends to cause protons to fly apart. The weak interaction with laws of conservation different from electromagnetism and the strong interaction was postulated to explain beta decay. Our observed material and neutral universe would signify the existence of another interaction that did conserve charge but did not conserve matter.

The conservation of electric charge Q is a universal law in the sense that it should be conserved in any interaction, known or yet unknown. However, Q should not be considered as a simple number but as the half sum of two irreducible quantities, the baryon lepton asymmetric number BAL = A-L (where A is the baryonic number and L is the leptonic number) and total flavor TF. Conservation of electric charge implies obviously conservation of Q (considered as a simple number) but also BAL and TF. We verify that electromagnetism and strong interaction which conserve Q, A and L and all individual flavors conserve obviously BAL and TF; that weak interaction which conserves Q, A and L conserves also BAL and TF. However, conservation of BAL does not necessarily imply conservation of A and L. In effect Δ BAL = 0 has another solution ΔA = ΔL = ±1 which points to a possible solution to explain how a material and neutral universe could arise evolving from an A = 0, L = 0, Q = 0 state to an A > 0, Q = 0 state through a process which would conserve BAL and TF without conserving separately A and L.

Par la méthode d'atténuation de l'effet Doppler-Fizeau (ajustement de la forme de la raie) nous avons tout particulièrement mesuré, dans les noyaux 68Ge, 70Ge et 66Zn obtenus par réaction (α, 2nγ) à Eα = 30 MeV, les durées de vie des états de haut spin. Le fait que la cible soit autoporteuse d'épaisseur finie de 1,2 à 1,5 mg/cm2, permet de déterminer les pouvoirs d'arrêt avec une bonne précision. Les résultats concernent une trentaine de niveaux, en particulier les niveaux de spin élevé (Jmax = 8 dans 70Ge, Jmax = 10 dans 68Ge, J max = (12) dans 66Zn) et font apparaître dans le cas des 68Ge et 70Ge la coexistence de niveaux faiblement et fortement collectifs, indiquant ainsi la mollesse de ces noyaux de transitions.

The 70Ga nucleus has been investigated via the 68Zn(α, pnγ)70Ga reaction at Eα = 23-40 MeV. The level scheme has been established by means of relative yield functions, electronic timing measurements, prompt and delayed coincidences and angular distributions of the emitted γ rays. The assignations of spins up to 9+ to levels up to 2.9 MeV excitation energy specify the components of the (νlg9/2) subshell.

Un schéma de niveaux a été obtenu pour le noyau 64Zn, en spectroscopie γ sur faisceau, par l'étude de la réaction 62Ni(α, 2nγ). Les caractéristiques Jπ = 6+ et 7(-) sont proposées pour les niveaux à 4 236 keV et 4 635 keV respectivement. La vie moyenne (τ = 130 ± 15 ps) de la transition Eγ = 641 keV désexcitant le niveau à 4 635 keV a été mesurée par la méthode du parcours de recul dans la réaction 55Mn(12C, p 2nγ).

The 390 keV isomeric state of 62Cu is assigned as Jπ = 4+. The magnetic hyperfine interaction has been observed in the 60Ni(α, pnγ) 62Cu reaction and the deduced Larmor period is consistent with known values of g and the hyperfine field of Cu in Ni.