nucl-th digest · Dec 9, 2016

Nuclear Clustering in Fermionic Molecular Dynamics

Clustering plays an important role in the structure of nuclei, especially for light nuclei in the

p

-shell. In nuclear cluster models these degrees of freedom are introduced explicitly. In the Resonating Group Method or in the Generator Coordinate Method the clusters are built from individual nucleons interacting via an effective nucleon-nucleon interaction; the total wave function is antisymmetrized. Fermionic Molecular Dynamics (FMD) goes beyond pure cluster models. It is a microscopic many-body approach using a Gaussian wave packet basis that includes the harmonic oscillator shell model and Brink-type cluster model wave functions as special cases. Clustering is not imposed but appears dynamically in the calculations. The importance of clustering for the understanding of bound states, resonances and scattering states is illustrated with examples discussing the charge radii of the Neon isotopes, the

^{3}

He(

α

γ

)

^{7}

Be capture reaction and the cluster states in the

^{12}

C continuum.

nucl-th4 citations

Medium effects in $Λ K^{+}$ pair production by 2.83 GeV protons on nuclei

E. Ya. Paryev🇷🇺 · M. Hartmann🇩🇪 · Yu. T. Kiselev🇷🇺

We study $Λ K^{+}$ pair production in the interaction of protons of 2.83 GeV kinetic energy with C, Cu, Ag, and Au target nuclei in the framework of the nuclear spectral function approach for incoherent primary proton--nucleon and secondary pion--nucleon production processes, and processes associated with the creation of intermediate $Σ^{0} K^{+}$ pairs. The approach accounts for the initial proton and final $Λ$ hyperon absorption, final $K^{+}$ meson distortion in nuclei, target nucleon binding, and Fermi motion, as well as nuclear mean-field potential effects on these processes. We calculate the $Λ$ momentum dependence of the absolute $Λ K^{+}$ yield from the target nuclei considered, in the kinematical conditions of the ANKE experiment, performed at COSY, within the different scenarios for the $Λ$ -nucleus effective scalar potential. We show that the above observable is appreciably sensitive to this potential in the low-momentum region. Therefore, direct comparison of the results of our calculations with the data from the ANKE-at-COSY experiment can help to determine the above potential at finite momenta. We also demonstrate that the two-step pion--nucleon production channels dominate in the low-momentum $Λ K^{+}$ production in the chosen kinematics and, therefore, they have to be taken into account in the analysis of these data.

nucl-thnucl-exCPC(2017)·8 citations

Friday·December 9, 2016

Nuclear Clustering in Fermionic Molecular Dynamics

Medium effects in $Λ K^{+}$ pair production by 2.83 GeV protons on nuclei

Affiliations

Nuclear Clustering in Fermionic Molecular Dynamics

Medium effects in ΛK+ pair production by 2.83 GeV protons on nuclei

Affiliations

Medium effects in $Λ K^{+}$ pair production by 2.83 GeV protons on nuclei