Research and Development for Near Detector Systems Towards Long Term Evolution of Ultra-precise Long-baseline Neutrino Experiments

Document submitted to the European Strategy For European Particle PhysicsDocument submitted to the European Strategy For European Particle PhysicsDocument submitted to the European Strategy For European Particle PhysicsWith the discovery of non-zero value of $\theta_{13}$ mixing angle, the next generation of long-baseline neutrino (LBN) experiments offers the possibility of obtaining statistically significant samples of muon and electron neutrinos and anti-neutrinos with large oscillation effects. In this document we intend to highlight the importance of Near Detector facilities in LBN experiments to both constrain the systematic uncertainties affecting oscillation analyses but also to perform, thanks to their close location, measurements of broad benefit for LBN physics goals. A strong European contribution to these efforts is possible

Proposal to Measure Hadron Scattering with a Gaseous High Pressure TPC for Neutrino Oscillation Measurements

We propose to perform new measurements of proton and pion scattering on argon using a prototype High Pressure gas Time Projection Chamber (HPTPC) detector, and by doing so to develop the physics case for, and the technological readiness of, an HPTPC as a neutrino detector for accelerator neutrino oscillation searches. The motivation for this work is to improve knowledge of final state interactions, in order to ultimately achieve 1-2% systematic error on neutrino-nucleus scattering for oscillation measurements at 0.6 GeV and 2.5 GeV neutrino energy, as required for the Charge-Parity (CP) violation sensitivity projections by the Hyper-Kamiokande experiment (Hyper-K) and the Deep Underground Neutrino Experiment (DUNE). The final state interaction uncertainties in neutrino-nucleus interactions dominate cross-section systematic errors, currently 5–10% at these energies, and therefore R&D is needed to explore new approaches to achieve this substantial improvement