Seagull and pion-in-flight currents in neutrino-induced $1N$ and $2N$ knockout

Understand

[Background] The neutrino-nucleus ($\nu A$) cross section is a major source of systematic uncertainty in neutrino-oscillation studies.

• A precise $\nu A$ scattering model, in which multinucleon effects are incorporated, is pivotal for an accurate interpretation of the data.
• [Purpose] In $\nu A$ interactions, meson-exchange currents (MECs) can induce two-nucleon ($2N$) knockout from the target nucleus, resulting in a two-particle two-hole (2p2h) final state.
• They also affect single nucleon ($1N$) knockout reactions, yielding a one-particle one-hole (1p1h) final state.