Monday 03 March 2025
Scientists are on a quest to uncover the secrets of neutrinos, tiny particles that zip through us and our surroundings at incredible speeds. To achieve this goal, researchers have designed an innovative experiment called NINJA, which uses a nuclear emulsion detector to measure these elusive particles with unprecedented precision.
The NINJA experiment is built around a large water target, where scientists can simulate neutrino interactions using protons from the J-PARC accelerator. The detection of these interactions is crucial for understanding the behavior of neutrinos, as they are essential for unraveling the mysteries of the universe.
One of the major challenges in detecting neutrino interactions is the presence of cosmic rays, which bombard the detector and create a massive amount of background noise. To overcome this issue, scientists have developed an emulsion shifter, which moves emulsion films to record tracks of charged particles from neutrino interactions. This innovative technology allows for both precise positioning and timing information, enabling researchers to separate neutrino signals from cosmic rays.
However, the NINJA experiment requires even more sophisticated detection capabilities. To achieve this, scientists have designed a new scintillation tracker, which consists of a monolithic plastic scintillator plane including scatterers. This detector provides both beam timing information and better position reconstruction than previous designs.
The performance of the new scintillation tracker was recently tested using positron beams at RARiS, Tohoku University. The results show that the tracker can reconstruct positions with an impressive resolution of just 1.44 mm when a charged particle enters perpendicularly, and 1.84 mm when the incident angle is 45 degrees.
The NINJA experiment aims to measure neutrino interactions using a larger water target than previous runs. With this increased target mass, scientists expect to observe approximately 750 CC0π2p events out of roughly 5480 CC events in all physics runs. The characteristic large opening angle of two protons in these interactions will be crucial for constraining the 2p2h interaction model.
The NINJA experiment is a significant step forward in understanding neutrino interactions, which are essential for advancing our knowledge of the universe. By precisely measuring these interactions, scientists can refine their models and gain insights into the behavior of neutrinos. The innovative technologies developed for this experiment will also have far-reaching implications for future particle physics research.
Cite this article: “Unraveling the Mysteries of Neutrinos with NINJA”, The Science Archive, 2025.
Neutrinos, Ninja Experiment, Nuclear Emulsion Detector, Cosmic Rays, Emulsion Shifter, Scintillation Tracker, Positron Beams, Particle Physics, Neutrino Interactions, Water Target
