A Novel Approach to Neutrino-Hydrogen Measurements

Abstract

The limited statistics of the available (anti)neutrino-hydrogen (H) interactions has been a longstanding impediment for high-energy neutrino physics. We discuss a practical way to achieve accurate (anti)neutrino-hydrogen measurements, addressing the principal limitations of earlier experiments. Interactions on hydrogen are extracted by subtracting measurements on thin dedicated graphite (pure C) and polypropylene (CH${}_2$) targets within a highly segmented low-density detector. A kinematic selection is used to increase the purities to 80-95\% before subtraction. A statistics of $\mathcal{O}(10^6)$ can be realistically achieved in modern neutrino beams for the various $\hat{I}½(\bar{\hat{I}}½)$-H event topologies. The availability of such samples would allow a precise determination of neutrino and antineutrino fluxes, as well as to directly constrain nuclear effects from a comparison with corresponding measurements on heavy materials within the same detector. The (anti)neutrino fluxes and the nuclear smearing are typically the leading sources of systematic uncertainties in long-baseline oscillation experiments. (Anti)neutrino-hydrogen interactions also provide an ideal tool for a wide range of precision tests of fundamental interactions.

Final published version, 21 pages, 8 figures, 3 tables