Quantifying uncertainties due to irreducible three-body forces in deuteron-nucleus reactions

Background: Deuteron-induced nuclear reactions are an essential tool for probing the structure of nuclei as well astrophysical information such $(n,\ensuremath{\gamma})$ cross sections. The deuteron-nucleus system is typically described within a Faddeev three-body model consisting neutron ($n$), proton ($p$), and target nucleus ($A$) interacting through pairwise phenomenological potentials. While techniques enable exact description dynamics, their predictive power limited in part by omission irreducible neutron-proton-nucleus force ($n\text{\ensuremath{-}}p\text{\ensuremath{-}}A$ 3BF).Purpose: Our goal to quantify systematic uncertainties stemming from reduction ($d+A$) dynamics picture three pointlike clusters via nucleon-nucleus forces, using testing grounds $d+\ensuremath{\alpha}$ scattering $^{6}\mathrm{Li}$ ground state. We particularly focus on quantifying arising full antisymmetrization ($A+2$)-body with fixed its state.Methods: adopt ab initio no-core shell coupled resonating group method (NCSM/RGM) compute microscopic $n\text{\ensuremath{-}}\ensuremath{\alpha}$ $p\text{\ensuremath{-}}\ensuremath{\alpha}$ interactions, use them means momentum-space Faddeev-type equations. Simultaneously, we also carry out calculations state six-body NCSM/RGM serve benchmark predictions given calculations.Results: By comparing results, show that $n\text{\ensuremath{-}}p\text{\ensuremath{-}}\ensuremath{\alpha}$ 3BF has non-negligible effect bound observables alike. Specifically, approach yields approximately 600 keV shallower than one obtained NCSM/RGM. Additionally, yield ${3}^{+}$ resonance located 400 higher energy compared result. shape angular distributions computed two approaches differ, owing discrepancy energy.Conclusions: potentials differ those microscopically These discrepancies due 3BF, which arises two-nucleon exchange terms $d\text{\ensuremath{-}}\ensuremath{\alpha}$ interaction not accounted calculations. This study lays foundation future parametrizations Pauli exclusion principle effects improved deuteron-induced reactions.