Description
Neutrino experiments over the years have been measuring oscillation parameters, however, some of them still remain unknown. This is the case for the $\theta_{23}$ octant, the value of $\delta_{CP}$, the neutrino mass ordering (normal or inverted ordering) and the nature of massive neutrinos - Dirac or Majorana. With new experiments under construction, such as DUNE, Hyper-K and JUNO, we are entering the era of precision, which means that, these experiments aim to enhance our ability to determine various properties of neutrinos with greater accuracy. Therefore, we have a good chance to test another crucial question in neutrino physics: is the neutrino mixing matrix unitary? In other words, are there really only three flavors of neutrinos? If the neutrino mixing matrix is found to be non-unitary, it would have profound implications for our understanding of the Standard Model. In our work, we study the impact of unitarity violation on sensitivity of standard oscillation parameters considering the next generation of long-baseline neutrino experiments (Hyper-K, DUNE) and we also verified whether these experiments have ability to constraint the new parameters related to non-unitarity.
