Speaker
Description
The neutrino oscillation is described by six independent parameters: three mixing angles $\theta_{23}$, $\theta_{12}$, and $\theta_{13}$), two mass-squared splittings, and one CP-violating phase ($\delta_{\mathrm{cp}}$). As of 2010, only $\theta_{13}$ and $\delta_{\mathrm{cp}}$ remained unknown. However, a non-zero value of $\theta_{13}$ is crucial for exploring CP violation in the lepton sector. In 2011, the T2K and Double Chooz experiments provided evidence of a non-zero $\theta_{13}$. From 2012 to the present, the Daya Bay reactor experiment has pushed the precision of $\theta_{13}$ down to 2.8%. Recently, Daya Bay achieved a 6.5% precision of $\theta_{13}$ in an independent measurement using the new capture-on-hydrogen sample. Although $\theta_{13}$ is currently the most precisely known mixing angle, it is expected to become the least precise with the next-generation experiments such as JUNO.
In this report, I will review the history and current status of $\theta_{13}$ measurements. The latest results from Daya Bay will be highlighted. The potential for further improving the precision of $\theta_{13}$ measurements will also be discussed. These high-precision measurements will constrain the PMNS neutrino mixing matrix to within 1% precision, opening the door to high-precision Unitarity tests in neutrino physics.
