Probing Nuclear Effects at the T2K Near Detector Using Single-Transverse Kinematic Imbalance

Stephen Dolan,Xianguo Lu,Tomislav Vladisavljevic,Alfons Weber,Luke Pickering

doi:10.1088/1742-6596/888/1/012203

Stephen Dolan, Xianguo Lu + Show 3 more

Open Access

https://doi.org/10.1088/1742-6596/888/1/012203

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Abstract

In order to make precision measurements of neutrino oscillations using few-GeV neutrino beams a detailed understanding of nuclear effects in neutrino scattering is essential. Recent studies have revealed that single-transverse kinematic imbalance (STKI), defined in the plane transverse to an incoming neutrino beam, can act as a unique probe of these nuclear effects. This work first illustrates that an exclusive measurement of STKI at the off-axis near detector of the T2K experiment (ND280) is expected to distinguish the presence of interactions with two nucleons producing two holes (2p-2h) from alterations of the predominant underlying cross-section parameter (MA - the nucleon axial mass). Such a measurement is then demonstrated with fake data, showing substantial nuclear model separation potential.

Highlights

Accelerator-driven long baseline neutrino oscillation experiments rely on the event-byevent reconstruction of neutrino energy from interactions of few-GeV neutrino beams with nuclear targets
It has recently been shown that single-transverse kinematic imbalance (STKI, defined in figure 1), characterising imbalance between an ejected lepton and nucleon in the plane transverse to an incoming neutrino can act as excellent probes of Fermi motion (FM) and final state interactions (FSI) in charged-current quasielastic (CCQE) neutrino scatters, in which a neutrino is converted to a charged lepton via the exchange of a W boson in the following reaction: ν n → −p [2,3,4]
To study ‘CCQE-like’ scattering it is instead preferred to measure all interactions without pions in the final state (CC0π interactions)

Summary

Introduction

Accelerator-driven long baseline neutrino oscillation experiments rely on the event-byevent reconstruction of neutrino energy from interactions of few-GeV neutrino beams with nuclear targets (see, e.g., [1]). In past cross-section measurements it has been difficult to separate the scale of a 2p-2h contribution from alterations to the predominant CCQE model parameter (MA - the nucleon axial mass) [6].

Results

Conclusion