Benchmarking $$\mathbf {\Lambda }$$NN three-body forces and first predictions for $$A=3-5$$ hypernuclei

Explicit expressions for the leading chiral hyperon-nucleon-nucleon three-body forces have been derived by Petschauer et al (Phys Rev C93:014001, 2016). An important prerequisite for including these three-body forces in few- and many-body calculations is the accuracy and efficiency of their partial-wave decomposition. A careful benchmark of the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>Λ</mml:mi></mml:math> NN potential matrix elements, computed using two robust and efficient partial-wave decomposition methods, is presented. In addition, results of a first quantitative assessment for the contributions of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>Λ</mml:mi></mml:math> NN forces to the separation energies in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>A</mml:mi> <mml:mo>=</mml:mo> <mml:mn>3</mml:mn> <mml:mo>-</mml:mo> <mml:mn>5</mml:mn></mml:mrow> </mml:math> hypernuclei are reported.