Identification of nuclear effects in neutrino and antineutrino interactions on nuclei using generalized final-state correlations

Xianguo Lu,Jan T Sobczyk

doi:10.1103/physrevc.99.055504

Abstract

In the study of neutrino and antineutrino interactions in the GeV regime, kinematic imbalances of the final-state particles have sensitivities to different nuclear effects. Previous ideas based on neutrino quasielastic interactions [Phys. Rev. C94, 015503 (2016), Phys. Rev. C95, 065501 (2017)] are now generalized to antineutrino quasielastic interactions, as well as neutrino and antineutrino pion productions. Measurements of these generalized final-state correlations could provide unique and direct constraints on the nuclear response inherently different for neutrinos and antineutrinos, and therefore delineate effects that could mimic charge-parity violation in neutrino oscillations.

Highlights

It has been well established that good understanding ofneutrino-nucleus cross sections in the GeV regime is necessary for constraining systematic errors in long-baseline oscillation experiments [1,2]
In the impulse approximation (IA) picture, which has a solid foundation in the few-GeV neutrino energy region, nuclear effects such as the target nucleon initial state (Fermi momentum and binding energy) and final-state interactions (FSIs) impact how individual scattering is seen in experimental setups
The next-generation long-baseline neutrino oscillation experiments DUNE and Hyper-Kamiokande aim to measure CP violation based on a comparison of the neutrino and antineutrino oscillation patterns

Summary

Introduction

It has been well established that good understanding of (anti)neutrino-nucleus cross sections in the GeV regime is necessary for constraining systematic errors in long-baseline oscillation experiments [1,2]. The most challenging part of this effort is to describe nuclear effects. In the impulse approximation (IA) picture, which has a solid foundation in the few-GeV neutrino energy region, nuclear effects such as the target nucleon initial state (Fermi momentum and binding energy) and final-state interactions (FSIs) impact how individual scattering is seen in experimental setups. It is very important to understand well any imprint of nuclear effects on neutrino and antineutrino scattering that could be misunderstood and taken in the data analysis as a manifestation of charge-parity (CP) violation. In addition to nuclear effects, the few-GeV energy region is complicated because of the overlap of many reaction channels, physics mechanisms, etc. A significant unknown is the contribution from the two-body current [called here twoparticle-two-hole (2p2h)], a subject of many experimental and theoretical studies [3,4,5,6,7,8,9,10,11,12]

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Results

Conclusion