A novel approach to neutrino–hydrogen measurements

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 (CH₂) 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 \(\nu ({\bar{\nu }})\)-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.