Measurement of Inclusive Charged-Current Neutrino Interactions on Oxygen

The student will work on the Fermilab-based Accelerator Neutrino-Nucleus Interaction Experiment (ANNIE), which serves as a 1% scale prototype for a new near detector for T2K-II and Hyper-Kamiokande. Two possible designs have been proposed for such a detector: nuPRISM and TITUS. Experience on ANNIE will be directly applicable to either design.

ANNIE is a part of the new short-baseline programme within Fermilab's Neutrino Division; it will be situated on-axis in the Booster Neutrino Beam (BNB). The experiment is starting construction now (Oct 2015), with Phase I to begin in Spring 2016. ANNIE is a small (~30 tonne) water Cherenkov detector with an upstream scintillator veto and a downstream muon range detector (MRD). The water will be loaded with a 0.1% concentration of gadolinium for neutron tagging. In preparation for nuPRISM and/or TITUS, ANNIE will pioneer a number of technical frontiers, including being the first Gd-loaded water Cherenkov detector to operate in a neutrino beam, and being the first particle physics experiment to use Large Area Picosecond Photo-Detectors (LAPPDs) for high-precision timing and spatial resolution.

In addition to these technical goals, ANNIE has two main physics goals: One is to measure the neutron yield as a function of energy in neutrino interactions. The other is to make measurements of the neutrino interactions themselves. Given the proximity to the BNB (100 meters from the target), ANNIE will see a large number of neutrinos (> 10,000 events per year) and should be able to accomplish these goals in a short period of time (2 - 3 years). Given this short timescale, ANNIE offers the student an unusual opportunity to participate in both the construction phase and the exploitation phase of the experiment. Over the course of his PhD, the student will gain experience with hardware (esp. PMTs, LAPPDs, and a MRD), software, and data analysis.

This work will culminate with a thesis, in which the student will measure the inclusive charged-current rates for neutrino interactions on oxygen in the energy range of ~0.8 GeV. Similar measurements have been made previously on carbon with the SciBooNE experiment and with the T2K near detector. However, no such measurement on oxygen exists as yet. Experience on T2K has shown that extrapolations from carbon to oxygen are non-trivial; even though the nuclei involved are simple, the nuclear models can be quite complicated, introducing large systematics into the far detector predictions for T2K. Thus, this measurement on oxygen at ANNIE will be immediately useful by T2K (and later by Hyper-Kamiokande) in constraining the uncertainty originating from neutrino interaction models.