Composition, decomposition and analysis of reactor antineutrino and electron spectra based on gross theory of β-decay and summation method

We applied the gross theory of β-decay to compose and decompose the reactor electron and antineutrino spectra emitted from ^235,238 U and ^239,241 Pu by summing up all the contributions from a large number of decaying fission-products (FPs). We make it clear what kinds of transition types and FP nuclides are important to shape the lepton spectra. Important role of the odd(Z)-odd(N) nuclides is also argued from the view point of the gross theory of β-decay. After taking the ambiguity in the current data for fission yields and _Qβ-values into account, we suggested a possibility that the high-energy part of the widely referred electron-spectra by Schreckenbach et al. might be too low. Our calculation supports the old experiment at University of Illinois.