Title: The new multi-ring charged current νμ 1π+ sample in T2K far detector

Speaker: Dr. Lakshmi S. Mohan, NCBJ, Warsaw

Abstract: Tokai to Kamioka (T2K) is an accelerator long baseline experiment in Japan. It measures the neutrino oscillation parameters by observing the disappearance of νμ (ν ̄μ) and the appearance of νe (ν ̄e) from a predomi- nantly νμ (ν ̄μ) beam over a baseline of 295 km. These ν and ν ̄ interact in the far detector Super-Kamiokande (SK), which is a water Cherenkov de- tector. At 0.6 GeV neutrino energy, where the T2K flux peaks, the most dominant interactions are charged current quasi--elastic, which result in single ring events. The next dominant are the charged current (CC) res- onant 1π production, which can give events with more than one rings. A new CC νμ 1π+ multi-ring sample from SK is added for the first time in T2K oscillation analysis. The selection criteria for the new sample and the estimation of far detector systematic uncertainties including this new sample will be discussed.