Neutrino Super Beam for lepton CP violation discovery based on the European Spallation Source

Abstract

on behalf of the ESSνSB ProjectFor the lepton CP violation discovery very intense neutrino beams are needed produced using very powerful proton beams. The proposed project, ESSνSB, is based on the European Spallation Source proton linac, the construction has started in 2014 and will finish by 2023. This linac will have a power of 5 MW producing protons of 2 GeV energy. The combination of the high beam intensity and the comparatively low proton energy allows the neutrino measurements to be made with a megaton Water Cherenkov neutrino detector installed 1000 m down in a mine at 540 km from the neutrino source, near the position of the second neutrino oscillation maximum. The relative variation of the electron neutrino yield with the CP violation angle δ CP is about three times larger than the first maximum. This implies that the measurement of δ CP is about three times less sensitive to the experimental systematic errors, which is the error determining the ultimate performance for discovery and measurement of leptonic CP violation. This observation has the potential to shed light on the matter-antimatter asymmetry in the Universe. The use of a large underground neutrino detector to measure the proton lifetime, detect cosmological neutrinos and neutrinos from supernova will also be possible.

ESSvSB: Update on secondary beam studies

“…ESSνSB is a long baseline neutrino super beam in Sweden proposed mainly for the discovery of the CP-violation in the leptonic sector and the neutrino mass hierarchy [1]. It will use the European Spallation Source (ESS) linac [2] that will be modified in order to accelerate up to 2 GeV protons for both the spallation source and the neutrino beam with 10 MW of power at 28 Hz, and the future Water Cherenkov MEMPHYS detector [3].…”

“…The detailed description of the ESSνSB super beam layout, the neutrino fluxes at the detector site and the physics results are presented in [1] and in the previous Neutrino Factory workshops proceedings [4].…”