Speaker
Description
T2K is a long-baseline experiment which measures parameters of neutrino oscillations. This can be done by analyzing the interaction of neutrinos close to the point of beam production and 295 km downstream. The detector located near the beam source, called ND280, primarily measures the interactions of neutrinos with carbon nuclei. The particles produced as a result of the interactions deposit energy in ND280 which is used to characterize the incoming neutrino flux and neutrino cross-sections before oscillations occur. Detecting a neutron and analyzing those events is tied to the understanding of final state interactions (FSI) models. Charged-current neutrino quasielastic scattering, the dominant interaction in the energy range of T2K, can produce a neutron only via FSI. Thus, by selecting events with no mesons, but with at least one neutron, and a negative muon, a selection enhanced in FSI events is obtained. Comparing these events to the ones with no identified neutron provides a better understanding of FSI and nuclear effects. However, neutrons are not easy to detect and because of this, they provide uncertainties in identifying the interactions happening in the detector and measuring cross-sections. ND280 has a newly installed Super Fine-Grained Detector (SFGD) made of plastic scintillator cubes. The upgraded detector capable of better position resolution and 3D reconstruction opens up the possibilities of improving the efficiency of neutron detection. Neutrons often leave a cluster, which is basically a few hits in neighbouring cubes, or less likely, a track produced by a proton knocked out by the neutron. With the sub-ns timing resolution achievable in the SFGD, the neutron's kinetic energy can be reconstructed using the measured time-of-flight. The talk will discuss which set of variables have been identified to distinguish true neutron tracks/clusters from background, and on the event level, neutron producing events from events without neutrons.
| Neutrino Properties | Neutrino cross-section studies |
|---|---|
| Neutrino Telescopes & Multi-messenger | N/A |
| Neutrino Theory & Cosmology | N/A |
| Data Science and Detector R&D | N/A |
