Measuring Dirac CP-violating phase with intermediate energy beta beam facility

TL;DR

This paper evaluates the potential of an intermediate energy beta beam facility to measure the Dirac CP-violating phase, highlighting the optimal baseline and detector configurations for CP violation discovery.

Contribution

It compares various beta beam setups and identifies a promising configuration using an antineutrino beam from $^6$He decay with a 1300 km baseline and a Water Cherenkov detector.

Findings

A 1300 km baseline with an antineutrino beam from $^6$He decay shows high CP discovery potential.

A 500 kton Water Cherenkov detector enhances sensitivity to the CP-violating phase.

Optimal setup aligns with the distance from FermiLAB to Sanford underground research facility.

Abstract

Taking the established nonzero value of $\theta_{13}$, we study the possibility of extracting the Dirac CP-violating phase by a beta beam facility with a boost factor $100<\gamma<450$. We compare the performance of different setups with different baselines, boost factors and detector technologies. We find that an antineutrino beam from $^6$He decay with a baseline of $L=1300$ km has a very promising CP discovery potential using a 500 kton Water Cherenkov (WC) detector. Fortunately this baseline corresponds to the distance between FermiLAB to Sanford underground research facility in South Dakota.