RSS Few-Body Systems

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  1. Abstract

    A method proposed to assign the symmetry character of the rovibrational spectrum of trimers has been applied to the case of H \(^+_3\) . This system, much lighter than previously investigated rare gas three body molecules such as Ar \(_3\) or Ne \(_3\) , constitutes a challenging example to test the possible limitations of this approach. Calculation of the corresponding rovibrational spectra for \(J=1\) and rotational constants and the corresponding comparison with results from hyperspherical coordinates methods reveals that distorsion Coriolis coupling terms, not accounted for in the original method, play a significant role for some specific symmetry representations.

  2. Abstract

    A brief overview of Faddeev-Yakubovsky equations is presented before deriving 5-body ones. Numerical formalism, enabling to solve these equations in configuration space for a system of five nucleons is described. Microscopic calculations are realized to determine phaseshifts of low energy neutron scattering on \(^4\) He and \(1/2^+\) resonance position of \(^5\) H, employing phenomenological MT I-III potential.

  3. Abstract

    We have presented the results for the single and double spin asymmetries in semi-inclusive deep inelastic scatterings for proton in a light front quark–diquark model. The asymmetries are found to satisfy certain inequalities. The model wavefunctions are modified to generate complex phase which is essential to produce asymmetries with Sivers and Boer-Mulders functions. The model predictions for Collins, Sivers and Boer-Mulders asymmetries are found to be consistent with data.

  4. Abstract

    Neutron knockout from \(^{11}\) Be due to the collision with a proton target is evaluated at 300 MeV/u using the three-body Faddeev/Alt-Grassberger-Sandhas (Faddeev/AGS) equations. The results for the Quasi-Free-Scattering reaction mechanism are discussed.

  5. Abstract

    We discuss the stability of tetraquark systems with two different masses. After some reminders about the stability of very asymmetric \(QQ{\bar{q}} {\bar{q}}\) tetraquarks, we demonstrate that in the all-heavy limit \(q \rightarrow Q\) , the system becomes unstable for standard color-additive models. We also analyze the consequences of symmetry breaking for \(Qq{\bar{Q}}{\bar{q}}\) configurations: we find a kind of metastability between the lowest threshold \(Q{\bar{Q}} + q{\bar{q}}\) and the highest one, \(Q{\bar{q}}+{\bar{Q}} q\) , and we calculate the width of the resonance. Our results are consistent with the experimental observation of narrow hadrons lying well above their lowest decay threshold.