Physics potential of ESSνSB in the presence of a light sterile neutrino

ESSνSB is a proposed neutrino super-beam project at the ESS facility. We study the performance of this setup in the presence of a light eV-scale sterile neutrino, considering 540 km baseline with 2 years (8 years) of ν (ν¯) run-plan. This baseline offers the possibility to work around the second oscillation maximum, providing high sensitivity towards CP-violation (CPV). We explore in detail its capability in resolving CPV generated by the standard CP phase δ13, the new CP phase δ14, and the octant of θ23. We find that the sensitivity to CPV induced by δ13 deteriorates noticeably when going from 3ν to 4ν case. The two phases δ13 and δ14 can be reconstructed with a 1σ uncertainty of ∼ 150 and ∼ 350 respectively. Concerning the octant of θ23, we find poor sensitivity in both 3ν and 4ν schemes. Our results show that a setup like ESSνSB working around the second oscillation maximum with a baseline of 540 km, performs quite well to explore CPV in 3ν scheme, but it is not optimal for studying CP properties in 3+1 scheme.