Speaker
Description
The Hyper Kamiokande (HyperK) experiment is a next generation neutrino oscillation experiment which aims to difinitively answer the question of whether neutrino oscillations violate CP symmetry, among other open questions in neutrino physics. In order to achieve its physics goals, HyperK will require exceptional constraints on uncertainties relating to the modeling of neutrino interactions, which will be provided by the near detector - ND280.
In particular, it will require high statistics samples of neutrino interactions on water, and to provide extremely high resolution measurements of the final state particles from those interactions. Work is ongoing to investigate the feasibility of a future upgrade to ND280, known as ND280++, with a number of new sub-detectors under consideration - which would aim to improve the capabilities of ND280 to rise to these challenges.
One possible sub-detector is based on the LiquidO detector technology, which uses an opaque scintillator in order to stochastically confine light close to it's point of production so that it can be read out via optical fibers. Such a detector could offer extremely fine position resolution while offering reduced construction challenges due to its homogeneous design. Furthermore, it offers the possibility of using water based scintillators which make it extremely appealing for use in HyperK due to the need to measure neutrino interactions on a water target.
Another possibility is to use scintillating fibers - thin fibers made of plastic scintillator - to achieve extremely fine positional resolution. Layers of these fibers can be interleaved with modules containing water to serve as the neutrino interaction target so that neutrino-water cross sections can be extracted.
Also under consideration is a so called "Hyper Fine Grained Detector" (HyperFGD). This design builds upon the previous success of the Super Fine Grained Detector (SuperFGD) which has already been constructed as part of the previous ND280 upgrade and began taking data in 2024. This design is based on 1cm cubes of scintillator read out by optical fibers and provides a high granularity 3D image of neutrino interactions. Several variants of this design are being considered, including the use of water based scintillator contained inside a 3D grid structure.
Here, we present simulation studies of these sub-detectors and discuss the challenges that arise therein.