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The most abundant nuclides in the cosmos have equal numbers of protons and neutrons. These include He 2 4 , C 6 12 , N 7 14 , O 8 16 , Ne 10 20 , Mg 12 24 , Si 14 28 , and S 16 32 , which together comprise 99.5% of ordinary polynucleonic matter. These are the most kinetically resilient (stable) nuclides within the highly exothermic reaction conditions of cosmic nucleosynthesis. This paper analyzes the relationship between the composition and relative cosmic abundance of light, stable nuclides. Structural symmetry emerges as a sensitive and specific predictor of superabundance within a proposed alternating nucleon model. The model derives ab initio from the proton’s radius (r =0.8414 fm), the hadron’s prolate shape (from the transition to the proton’s first excited state, the ∆+(1232) resonance), and the separation distance between a pair of bound nucleons (≈ 0.8 fm, from the nucleon-nucleon potential). Various nucleon geometries were considered for each nuclide, with preference given to structures having optimal numbers of stable proton-neutron short-range interactions and whose model radii (derived from the regular polygon radius formula) best correlate with experimental charge radii (r(31)=.98, p<.001). Remarkably, the best-fit solutions for the eight superabundant Z=N nuclides categorically demonstrate bilateral structural symmetry, in which neutrons reflect protons on opposite sides of a bisecting chiral plane. Conversely, when an element’s stable isotopes are compared, the best-fit structures in which nucleon symmetry is not possible (generally because proton and neutron numbers are unequal) are less abundant by ≈ 2 orders of magnitude. Symmetry is ubiquitous in nature, and the proposed alternating nucleon model is consistent with the axiom that structural symmetry confers structural stability.

Lifetimes of the 21+ states in 44Ti, 48,50Cr, and 52Fe were determined with high accuracy exploiting the recoil distance Doppler-shift method. The reduced E2 transition strengths of 44Ti and 52 Fe differ considerably from previously known values. A systematic increase in collectivity is found for the N = Z nuclei compared to neighboring isotopes. The B(E2) values along the Ti, Cr, and Fe isotopic chains are compared to shell-model calculations employing established interactions for the 0f 1p shell, as well as a novel effective shell-model Hamiltonian starting from a realistic nucleon-nucleon potential. The theoretical approaches underestimate the B(E2) values for the lower-mass Ti isotopes. Strong indication is found for particle-hole cross-shell configurations, recently corroborated by similar results for the neighboring isotone 42 Ca. A detailed manuscript has meanwhile been published in Physics Letters B [1].

A hyperon–nucleon potential for the strangeness S = - 1 sector ( Λ N , Σ N ) up to third order in the chiral expansion is presented. SU(3) flavor symmetry is imposed for constructing the interaction, however, the explicit SU(3) symmetry breaking by the physical masses of the pseudoscalar mesons and in the leading-order contact terms is taken into account. A novel regularization scheme is employed which has already been successfully used in studies of the nucleon–nucleon interaction within chiral effective field theory up to high orders. An excellent description of the low-energy Λ p , Σ - p and Σ + p scattering data is achieved. New data from J-PARC on angular distributions for the Σ N channels are analyzed. Results for the hypertriton and A = 4 hyper-nuclear separation energies are presented. An uncertainty estimate for the chiral expansion is performed for selected hyperon–nucleon observables.

The nucleus contains protons and neutrons, each combining three fractionally-charged +2/3e up and −1/3e down quarks. Fusion occurs when small nuclei collide with sufficient kinetic energy to overcome the repulsive Coulomb barrier, at which point the strong nuclear force binds the nuclei together. Fusion is thus understood as an interplay between two fundamental forces, the electrostatic at far range and the strong nuclear force at close range. Here, we mathematically model the entire fusion potential curve based solely on the geometry of electrostatic interactions and without recruiting the strong nuclear force . The deuteron is modelled as a linear sequence of six alternating, equally-spaced quark charges. The linear geometry derives from the accepted prolate spheroid shape of the nucleon, wherein spin-spin forces repel like-flavored quarks to opposite positions (qualitatively) within the cigar-shaped nucleon, leaving the unlike-flavored quark in the center. The Argonne v18 nucleon-nucleon potential (≈the proton's radius) accounts for the nucleon-nucleon separation. The Coulomb barrier height is quantified from the electrostatic potentials between the quarks on one deuteron with the quarks on the other as the nuclei approach at incremental distances. The net positive charge on each deuteron results in far-range repulsion. Within ≈1 fm, however, close-range attraction results from regularly alternating/unequal charge geometry as the +2/3e charges on one deuteron align with the −1/3e charges on the other. The model-predicted Coulomb barrier height Vc =0.57 MeV approximates the textbook calculation Vc =0.34 MeV (which assumes a spherical nucleus). This compares with a proton-deuteron barrier prediction Vc =0.88 MeV (0.48 MeV textbook). A negligible neutron-deuteron barrier prediction Vc =0.00946 MeV is consistent with the empirical knowledge of neutron fusion (i.e., strong close-range attraction, but Vc =0). The model may prove helpful in parameterizing nuclear fusion, indicating a 46% difference in Coulomb barrier height depending on deuteron orientation (axial versus antiparallel) at the time of collision/fusion.

We review how nuclear forces emerge from low-energy quantum chromodynamics (QCD) via chiral effective field theory (EFT). During the past two decades, this approach has evolved into a powerful tool to derive nuclear two- and many-body forces in a systematic and model-independent way. We then focus on the nucleon-nucleon (N N) interaction and show in detail how, governed by chiral symmetry, the long- and intermediate-range of the N N potential builds up order by order. We proceed up to sixth order in small momenta, where convergence is achieved. The final result allows for a full assessment of the validity of the chiral EFT approach to the N N interaction.

In this work, Hyperspherical Harmonic Expansion (HHE) formalism aided by supersymmetric quantum mechanics is used to study bound and resonant states of 14Be in the three-body (12Be+ n + n) cluster model, and the analysis of the resonant states close to the binding threshold utilizes supersymmetric quantum mechanics (SSQM). GPT nucleon-nucleon potential together with SBB core-nucleon potential is chosen for the solution of three-body Schrödinger equation to get the lowest bound state energy and wave function. In the next stage, energy and wave function of the bound state is used to derive an isospectral potential that exhibit deep well following a strong barrier facilitating confinement (or trapping) of particle inside it at some positive energy (E>0). The trapping probability when plotted against energy shows a prominent peak at the energy of resonance. WKB approximation is used to determine the width of resonance width. Calculated resonance energy and width of resonance are compared with those measured experimentally for the promising neutron halo candidate, the 14Be.

We approach the calculation of the nuclear matrix element of the neutrinoless double-β decay process, considering the light-neutrino-exchange channel, by way of the realistic shell-model. In particular the focus of our work is spotted on the role of the short-range correlations, which should be taken into account because of the short-range repulsion of the realistic potentials. Our shell-model wave functions are calculated using an effective Hamiltonian derived from the high-precision CD-Bonn nucleon-nucleon potential, the latter renormalized by way of the so-called Vlow-k approach. The renormalization procedure decouples the repulsive high-momentum component of the potential from the low-momentum ones by the introduction of a cutoff Λ, and is employed to renormalize consistently the two-body neutrino potentials to calculate the nuclear matrix elements of candidates to this decay process in mass interval ranging from A = 76 up to A = 136. We study the dependence of the decay operator on the choice of the cutoff, and compare our results with other approaches that can be found in present literature.

We present results on the anisotropic transverse flow of kaons (K + , K 0 S and K − ) in Au+Au collisions at √s NN = 2:42 GeV measured with HADES. It was proposed already in the mid-nineties that kaon flow close to its production threshold might be a good probe for the kaon-nucleon potential and, consequently, or the nuclear equation-of-state. The presented analysis was performed on more than 2 billion events of the 40% most central collisions, which opened the possibility of analyzing the kaon flow differentially as a function of transverse momentum, rapidity, and centrality, even in this low-energy regime. The measurements are compared to microscopic transport model predictions and to other data at similar collision energies. Implications on the properties of compressed nuclear matter will be discussed.

This contribution reports on a shell-model study of nuclei in the 132Sn region employing a realistic effective interaction derived from the CD-Bonn nucleon-nucleon potential renormalized through the use of the Vlow−k approach. We shall focus on some selected results for nuclei with a few valence particles and/or holes with respect to 132Sn, namely Sn isotopes with N > 82 and 130Te, which have, in part, been discussed in previous papers. Results are compared with experiments, and predictions that may provide guidance to future experiments are also discussed. It is the aim of this contribution to underline the importance of studying 132Sn neighbours to acquire a deep understanding of nuclear structure, that may be very useful also in other physics fields, and to show that the realistic shell model is a very effective tool to conduct these studies.

Characteristics of the quasi-bound state in the K-pp system strongly depend on the model of antikaon–nucleon interaction and weakly—on the nucleon–nucleon potential. In the present paper, dynamically exact Faddeev-type calculations with coupled K¯NN and πΣN were performed using different models of the ΣN and πN interactions to study the influence of these “less important” interactions on the three-body result. In addition, dynamically exact three-body Faddeev-type AGS calculations with three coupled particle channels K¯NN-πΣN-πΛN were performed.