Description
The T2K experiment is a long-baseline accelerator neutrino experiment that measures $\nu_e$ appearance and $\nu_\mu$ disappearance from the $\nu_\mu$ beam by observing neutrino events at the near and far detectors. The near detector (ND280) stands 280 metres, and the far detector (Super Kamiokande) stands 295 km away from the beam production target. Super Kamiokande (SK) is a 50 kton water-Cherenkov detector that observes Cherenkov rings from charged particles produced in neutrino interactions with water.
In the present oscillation analyses, T2K uses both single and multi-ring samples for $\nu_\mu$ at SK, but only single-ring samples for $\nu_e$. Charged current single $\pi^+$ events form the second most dominant signal events in $\nu_e$ appearance studies, of which events with $\pi^+$ below Cherenkov threshold is used in the analysis (1 e-like ring and a decay electron signature). Addition of the sample with $\pi^+$ above the Cherenkov threshold, consisting of 1 e-like ring and 1 $\pi^+$-like ring can increase the $\nu_e$ statistics and thus our sensitivity to $\delta_{CP}$. In this poster, I will discuss the cuts-based selection of 2-ring $\nu_e$ CC1$\pi^+$ events, the dominant backgrounds and the optimisation technique for the selection cuts.
| Collaboration | T2K experiment |
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