DUNE Phase II: Scientific Opportunities, Detector Concepts, Technological Solutions

TL;DR

DUNE Phase II aims to expand neutrino research capabilities with upgraded detectors and beam power, enabling groundbreaking science in neutrino physics, astrophysics, and beyond standard model phenomena.

Contribution

This paper outlines the planning, technological concepts, and scientific opportunities for DUNE Phase II, including detector upgrades and R&D strategies.

Findings

Introduction of additional far detector modules and upgraded near detector complex.

Enhanced beam power at 2.1 MW to improve experimental sensitivity.

Expanded physics scope including neutrino oscillations, astrophysics, and beyond standard model searches.

Abstract

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.