Speaker
Description
Precision measurements of neutrino oscillation parameters in the Tokai to Kamioka (T2K) long-baseline neutrino experiment require a robust and accurate understanding of neutrino–nucleus interactions. The T2K near detector complex, ND280, is specifically designed to constrain neutrino flux parameters and cross-section models through detailed analyses of neutrino interactions. As part of the T2K-II phase, the ND280 complex has been upgraded to significantly enhance its performance through the addition of three advanced sub-detectors: a Super Fine-Grained Detector (SFGD), two High-Angle Time Projection Chambers (HA-TPCs), and six high-resolution Time-of-Flight (TOF) modules. The combination of these systems provides nearly 4π angular acceptance for charged particles, while the finer granularity lowers the proton momentum detection threshold to 300 MeV/c and facilitates neutron identification. As of June 2024, the new sub-detectors have been installed and are actively taking data.
This talk presents the first analyses using data from the newly installed TOF detector. The TOF currently achieves a measured timing resolution of approximately 180 picoseconds, supporting both precise particle identification and the rejection of interactions originating outside the fiducial volume. The performance of the TOF has been evaluated through detailed studies of the time resolution, signal efficiency, and geometrical alignment, all of which indicate strong detector capability with further improvements expected from ongoing calibration efforts. Inter-detector calibration and track-matching studies with other ND280 sub-detectors further illustrate the system's robustness for high-precision neutrino interaction measurements. Finally, the talk will outline the potential benefits of using TOF information to support and improve current and future analyses.
