Neutron-proton scattering with lattice chiral effective field theory at next-to-next-to-next-to-leading order

Understand

We present a new lattice formulation of chiral effective field theory interactions with a simpler decomposition into spin channels.

• With these interactions the process of fitting to the empirical scattering phase shifts is simplified, and the resulting lattice phase shifts are more accurate than in previous studies.
• We present results for the neutron-proton system up to next-to-next-to-next-to-leading order for lattice spacings of $1.97$, $1.64$, $1.32$, and $0.99~{\rm fm}$.
• Our results provide a pathway to $\textit{ab initio}$ lattice calculations of nuclear structure, reactions, and thermodynamics with accurate and systematic control over the chiral nucleon-nucleon force.