Mohapatra has worked extensively on neutrino physics. He is one of the proponents of the seesaw mechanism for neutrino masses and the left-right symmetric theories of weak interactions. He is also the co-proponent of the new particle related to neutrino mass called the "majoron." He suggested the idea of neutron-anti-neutron oscillation, which led to many experimental searches for this process.

Mohapatra has several seminal papers on grand unified theories of particles and forces. He also co-authored a paper on the possibility that there may be a small violation of the celebrated Pauli Exclusion Principle inQuantum Mechanics, which led to several experimental searches for this effect. Mohapatra published a single-author book on "Unification and Supersymmetry: Frontiers of Quark Lepton Physics" published by Springer-Verlag, which went into third edition in 2003, and coauthored a book on "Massive Neutrinos in Physics and Astrophysics" published by World Scientific, which also went into a third edition in 2004.

Mohapatra is a fellow of the American Physical Society and a fellow of the Indian National Academy of Science. He was awarded the Humboldt Prize in 2005 for his research on neutrinos and was awarded the Distinguished Scientists award by the American chapter of the Indian physicists association in 2000. He was awarded the degree of Doctor of Science by the North Orissa University.

Written in a semi-popular style for those with a general physics background

Explains in clear arguments and real-world applications the importance of this elusive subatomic particle

Injects a human element through its recounting of the history and scientists behind neutrino physics