Contributions of 2π exchange, 1π exchange, and contact three-body forces in NNLO chiral effective field theory to H<mml:…

Faddeev calculations of hypertriton (_^3H) separation energy are carried out, incorporating all next-to-next-to-leading-order three-body forces (3BFs) in chiral effective field theory: 2 exchange, 1 exchange, and contact interactions. The 1 exchange and contact interactions are rewritten in a form suitable for evaluating partial-wave matrix elements. The -deuteron folding potentials constructed from these 3BFs are evaluated to demonstrate their contributions to _^3H. The 1 exchange interaction provides an attractive effect in which the d-state component of the deuteron wave function plays an important role. The attractive contribution tends to cancel the repulsive ones from the 2 exchange and contact 3BFs. Faddeev calculations show that the net effect of the 3BFs to the _^3H separation energy is small in a range between -5 to +20 keV, depending on the NN interaction used. Although these results are based on speculative low-energy constants, they can serve as a reference for further investigations.