Two particle-two hole final states in quasi elastic neutrino-nucleus interactions

TL;DR

This paper investigates the role of two particle-two hole states and interference effects in neutrino-nucleus scattering, proposing a new method to treat one- and two-nucleon currents simultaneously to better understand observed cross section anomalies.

Contribution

It introduces a novel approach to consistently include one- and two-nucleon current contributions in neutrino-nucleus interaction calculations.

Findings

Interference between one- and two-nucleon currents significantly impacts cross sections.

Two particle-two hole states are crucial in explaining the excess observed in experiments.

A new theoretical framework is outlined for more accurate modeling.

Abstract

The excitation of two particle-two hole final states in neutrino-nucleus scattering, not taken into account in Monte Carlo simulations for data analysis, has been advocated by many authors as the source of the excess cross section observed by the MiniBooNE collaboration in the quasi elastic channel. We analyse the mechanisms leading to the appearance of two particle-two hole states, and show that interference between the amplitudes involving one- and two-nucleon currents, not consistently included in existing calculations, plays a major role. A novel approach allowing to treat one- and two-nucleon current contributions on the same footing is outlined.