e2a

Spokesperson

Steven Dytman

Year

2025

Abstract

Extracting accurate results from neutrino oscillation and cross section experiments requires ac- curate simulation of the neutrino-nucleus interaction. The rescattering of outgoing hadrons (final state interactions) by the rest of the nucleus is an important component of these interactions. We present a new measurement of proton transparency (defined as the fraction of outgoing protons that emerge without significant rescattering) using electron-nucleus scattering data recorded by the CLAS detector at Jefferson Laboratory on helium, carbon, and iron targets. This analysis uses a new data-driven method to extract the transparency. It defines transparency as the ratio of electron-scattering events with a detected proton to quasi-elastic electron-scattering events where a proton should have been knocked out. Our results are consistent with previous measurements which determined transparency from the ratio of measured events to theoretically predicted events. We find that the GENIE event generator, which is widely used by oscillation experiments to simulate neutrino-nucleus interactions, needs to better describe both the nuclear ground state and proton rescattering in order to reproduce our measured transparency ratios, especially at lower proton momenta.

Comment

Beam energies: 2.261 and 4.461 GeV with helium, carbon, and iron targets. All targets had natural isotopic abundance, He (100%), C (98.9%) and Fe (91.8%).

Publication

1. S. Dytman, M. Betancourt, N. Steinberg, Lawrence Weinstein, A. Ashkenazi, J. Tena-Vidal, A. Papadopoulou, G. Chambers-Wall, and J. Smith Proton Transparency and Neutrino Physics: New methods and Modeling //

Quantities

T

Measurements