First Measurement of the Electron-Neutrino Charged-Current Pion Production Cross Section on Carbon with the T2K Near Detector

October 10, 2025

The T2K Collaboration presents the first measurement of electron neutrino-induced charged-current pion production on a predominantly carbon target in a restricted kinematical phase space. This is performed using data from the 2.5° off-axis near detector, ND280. The differential cross sections with respect to the outgoing electron and pion kinematics, in addition to the total flux-integrated cross section, are obtained. Comparisons between the measured and predicted cross-section results using the neut, genie, and nuwro Monte Carlo event generators are presented. The measured total flux-integrated cross section is [2.52±0.52⁢(stat)±0.30⁢(syst)]×10−39  cm2 nucleon−1, which is lower than the event generator predictions.

The differential flux-integrated cross-section results and predictions from neut, genie, and nuwro as a function of particle kinematics.