M.Zh. Shmatikov

The forward-backward spectator asymmetry in low-energy pD annihilation

Abstract The forward-backward asymmetry of spectators in low-energy p D annihilation is shown to be due to Re f( p p). The energy dependence of the latter can be described in terms of a broad p p resonance with mass ≈ 1980 MeV.

Multiquark clusters in nuclei. distributions ofu- andd-quarks

Effects related to the possible admixture of multiquark (mainly 12q) clusters (bags) in nuclei are discussed. In particular the differencies in theu- andd-quark distributions inN≠Znuclei are considered. The quark distribution function is assumed to consist of two components: the nucleon component and the bag one (mainly the 12q-bag). The yields ofπ-mesons and nucleons into the backward hemisphere are governed mainly by the contribution of the bag component. It comes from the available data on theπ+/π− andn/p ratios that thed-quarks in the bag component of nuclei withN>Z are “more soft” than theu-quarks in contrast to the situation in the nucleon component. The manifestation of the latter effect in theA-dependence of the ratio of structure functionsR=F2A(x)/F2D(x) is also discussed.

Dispersion like treatment of a three-particle spectrum

Abstract The general description of the three-particle spectrum with its two main properties, the Thomas theorem and the Efimov effect, is given. The spectrum of levels generated by only two-particle (particle + pair bound state) contributions to the unitarity condition is shown to have none of these properties. Taking into account the three-particle intermediate states in the unitarity condition, the N / D equations reproduce both the Thomas theorem and the Efimov effect. The quantitative calculation of a three-particle spectrum by means of N / D equations, making use of only on-shell characteristics of the two-particle system, is in reasonable agreement with the solution of the Faddeev equation.

P-Matrix analysis of the dibaryon1D2 resonance

We study the relation between intermediate energy nucleon-nucleon scattering and the eigenstates of the bag model using theP-matrix formalism. Data of existing phase-shift analyses are employed to calculate theP-matrix for the coupled1D2(pp) and5S2(NΔ) channels in the energy region above the Δ-isobar production threshold. TheP-matrix calculated for the equivalent hadronic bag radiib=1.4−1.5 fm is shown to have a pole in the mass range 2.31–2.34 GeV in agreement with the MIT bag model prediction of theI=1,JP=2+ 6-quark state with the mass 2.34 GeV. The hadronic shift of this state is shown to be ≈200 MeV; the dibaryon pole of theS-matrix is located at the energy 2.15–2.17 GeV with the width ≈100–200 MeV.

Higgs scalars in semileptonic processes

Interactions of Higgs scalars are discussed in a gauge theory of weak interactions. The construction of the mass matrix for fermions in vector-like theories similar to the gauge theory is also discussed, a few possible extensions of the gauge model to include hadrons and corrections to interactions of weak charged currents due to exchanges by Higgs S± -scalars. It was shown that due to these corrections apparent breaking of the Callen-Freiman relation for Ke3 form factors is possible, but the GoldbergerFreiman relation survives in its original form.

Lepton charge and model of weak interactions with μ-e transitions

Abstract The gauge model of weak interactions is proposed and μ±↔e∓ transitions predicted by the model are discussed. Estimates are given for μ±→e∓ transitions on hadrons like K+→π−μ+e+ with Γ (K+→π−μ+e+) ≅ 10−11 Γ(K+ and μ− capture on nuclei with W(μ−→e+) ≅ 10−12 W(μ− → ν). Single μ± production in e∓ beams with a cross section δ ∼ 10−42−10−41 cm2 is predicted.