NOvA finds 2p2h-dominated sample to be unexplained by current models

NOvA thinks of itself as a neutrino oscillation experiment first, but Tufts neutrino group members have been working hard to make it a lot more than that. The collaboration just released its first dedicated study on so-called “two-particle, two-hole” interactions (where a neutrino strikes a nucleus and knocks two nucleons out of it, leaving two “holes” behind), based on Travis Olson’s Ph.D. work and his successful defense in 2021.

The measurements show that the data disagree heavily with leading theoretical treatments of this process. The nuclear physics of this kind of interaction is quite challenging to model theoretically, so this isn’t a total surprise—but data like what’s in this paper is an important benchmark for future theory work to be compared against.