Benchmarking of neutrino energy reconstruction methods using electron-deuterium scattering data

Abstract

Neutrinos exist in one of three types or “flavors” (𝜈ₑ , 𝜈 subscript 𝜇, or 𝜈 subscript 𝜏 ) which oscillate from one to another when propagating through space. Understanding the detailed features of this phenomenon can provide new insight into the nature of our universe. Neutrinos oscillate as a function of their propagation distance divided by their energy (𝐿/𝐸), so experiments extract oscillation parameters by measuring the neutrino energy distribution at different locations. As accelerator-based oscillation experiments cannot directly measure 𝐸, their interpretation relies heavily on phenomenological models of neutrino-nucleus interactions to infer 𝐸. Here, we exploit the similarity of electron- and neutrino-nucleus interactions, and use electron-scattering data with known beam energies to test energy reconstruction methods and interaction models. In particular, we analyze 5 GeV electron-deuteron scattering data measured using the large-acceptance CLAS detector at Jefferson Lab. Despite deuterium having a simple nucleus that is relatively well-understood, we find that large nuclear effects can bias the electron beam-energy reconstruction. We thus develop a set of event selection cuts that strongly suppress nuclear effects and propose a viable path for precision measurements. We further compare our data with the theoretical predictions of the GENIE event generator, commonly used by most neutrino experiments based in the US, to validate simulation models used for interpreting lepton-nucleus scattering reactions.