Search for nucleon-nucleon correlations in neutrino-argon scattering

A sample of two-proton and no-pion events selected in the ArgoNeuT neutrino scattering experiment on a liquid argon target [Phys. Rev. D 90, 012008 (2014)] is analyzed with the NUWRO Monte Carlo event generator. An attempt is made to estimate how likely it is to obtain observed numbers of laboratory frame and reconstructed back-to-back nucleon pairs. For laboratory frame back-to-back events, a clear data/Monte Carlo discrepancy is seen. For the reconstructed nucleon pairs, a good agreement is reported. We provide a simple kinematical argument that explains why this accordance is expected.