Re-evaluation of the T2KK physics potential with simulations including backgrounds

Abstract

The Tokai-to-Kamioka-and-Korea (T2KK) neutrino oscillation experiment under examination can have a high sensitivity to determine the neutrino mass hierarchy for a combination of relatively large (\sim 3.0^circ) off-axis angle beam at Super-Kamiokande (SK) and small (\sim 0.5^circ) off-axis angle at L \sim 1,000km in Korea. We elaborate previous studies by taking into account smearing of reconstructed neutrino energy due to finite resolution of electron or muon energies, nuclear Fermi motion and resonance production, as well as the neutral current π^0 production background to the nu_mu to nu_e oscillation signal. It is found that the mass hierarchy pattern can still be determined at 3sigma level if sin^22thata_rct \quiv 4|U_{e3}|^2(1-|U_{e3}|^2) \gsim 0.08(0.09) when the hierarchy is normal (inverted) with 5 \times10^{21} POT exposure, or 5 years of the T2K experiment, if a 100kton water cherenkov detector is placed in Korea. The π^0 backgrounds deteriorate the capability of the mass hierarchy determination, whereas the events from nuclear resonance productions contribute positively to the hierarchy discrimination power. We also find that the π^0 backgrounds seriously affect the CP phase measurement. Although δ_mns can still be constrained with an accuracy of \sim \pm 45^circ (\pm 60^circ) at 1sigma level for the normal (inverted) hierarchy with the above exposure if sin^22theta_rct \gsim 0.04, CP violation can no longer be established at 3sigma level even for delta_mns=\pm 90^circ and sin^22theta_rct=0.1. About four times higher exposure will be needed to measure delta_mns with \pm 30^circ accuracy.

46 pages, 13 figures

Cited by in corpus (14)

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• Physics potential of the ESS$\nu$SB
• Global oscillation data analysis on the $3\nu$ mixing without unitarity
• Sensitivity of T2KK to the non-standard interaction in propagation
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• A Novel Approach to Study Atmospheric Neutrino Oscillation
• Physics potential of neutrino oscillation experiment with a far detector in Oki Island along the T2K baseline
• Heavy neutrino mixing in the T2HK, the T2HKK and an extension of the T2HK with a detector at Oki Islands
• On ${\theta }_{23}$ Octant Measurement in $3+1$ Neutrino Oscillations in T2HKK
• Improving CP Measurement with THEIA and Muon Decay at Rest
• Revisiting T2KK and T2KO physics potential and ${\nu }_{\mu }$ - ${\bar{\nu }}_{\mu }$ beam ratio