Complex sentence: In 1931, Enrico Fermi renamed Pauli's "neutron" to neutrino and, in 1934, he published a very successful model of beta decay in which beta particles and neutrinos were created.
Split into simpler sentences: In 1931, Enrico Fermi renamed Pauli's "neutron" to neutrino. In 1934, Fermi published a landmark theory for beta decay in which beta particles and neutrinos were created.