Neutrino scattering off $^{16}$O in coupled-cluster theory

Accurately modeling the interactions of neutrinos with $^{16}$O is essential for neutrino experiments that employ (heavy) water Cherenkov detectors. Recent advances in the chiral-effective-field-theory description of nuclear forces and electroweak currents and in nuclear many-body theory have positioned us to obtain reliable predictions for $ u$-$^{16}$O cross sections up to the quasielastic kinematic regime. I will present recent results for inclusive response functions computed in coupled-cluster theory, which goes beyond the mean-field approximation to approach the exact numerical solution of the many-body Schroedinger equation as a controlled expansion. I will discuss the prospect of providing vital theory support for controlling the systematic uncertainty in the future T2HK experiment in Japan.