Physics - High Energy Physics - Experiment Physics - Instrumentation and Detectors
The international collaboration designing and constructing the Deep
Underground Neutrino Experiment (DUNE) at the Long-Baseline Neutrino Facility
(LBNF) has developed a two-phase strategy toward the implementation of this
leading-edge, large-scale science project. The 2023 report of the US Particle
Physics Project Prioritization Panel (P5) reaffirmed this vision and strongly
endorsed DUNE Phase I and Phase II, as did the European Strategy for Particle
Physics. While the construction of the DUNE Phase I is well underway, this
White Paper focuses on DUNE Phase II planning. DUNE Phase-II consists of a
third and fourth far detector (FD) module, an upgraded near detector complex,
and an enhanced 2.1 MW beam. The fourth FD module is conceived as a "Module of
Opportunity", aimed at expanding the physics opportunities, in addition to
supporting the core DUNE science program, with more advanced technologies. This
document highlights the increased science opportunities offered by the DUNE
Phase II near and far detectors, including long-baseline neutrino oscillation
physics, neutrino astrophysics, and physics beyond the standard model. It
describes the DUNE Phase II near and far detector technologies and detector
design concepts that are currently under consideration. A summary of key R&D
goals and prototyping phases needed to realize the Phase II detector technical
designs is also provided. DUNE's Phase II detectors, along with the increased
beam power, will complete the full scope of DUNE, enabling a multi-decadal
program of groundbreaking science with neutrinos.