22.11.2022 15:15
Verleihung des Dr. Klaus Erkelenz Preises und Vortrag der Laureatin Hoai Le, FZ Jülich
Single- & double-strangeness hypernuclei in the framework of the NCSM and χEFT
Abstract: Due to the scarcity of hyperon-nucleon (YN) and the lack of hyperon-hyperon (YY) scattering data, hypernuclear systems with strangeness S = −1,−2 are indispensable laboratories to explore the underlying baryon-baryon (BB) interactions. In this talk, I investigate light hypernuclei with A = 4−8 from a microscopic level using the ab initio Jacobi no-core shell model (J-NCSM) in combination with BB potentials derived within the framework of chiral effective field theory. The employed BB interactions are softened with the similarity renormalization group (SRG) evolution in order to speed up the convergence of the NCSM calculations. Such an evolution is only approximately unitary when the so-called SRG induced three- and higher-body forces are omitted. The impact of the SRG evolution on the Λ separation energies in the A = 4−7 systems, when only SRG-evolved two-body and when both two- and three-body forces are included, is thoroughly investigated. For the latter scenario, I study predictions of the two almost phase-equivalent NLO13 and NLO19 potentials for A = 4−7 hypernuclei. I further explore charge-symmetry breaking (CSB) splittings in the A = 7, 8 multiplets employing the two NLO YN potentials that include also the leading CSB potential, whose strength has been fitted to the presently established CSB in the A = 4 doublets. Finally, predictions of the NLO YY potential for the light Ξ systems (NNNΞ, 5ΞH, 7ΞH) and for the s-shell ΛΛ hypernuclei ( 4ΛΛH, 5ΛΛHe, 6ΛΛHe) are briefly discussed.