The most basic particle physics theory currently being experimentally verified is the Standard Model, but there are phenomena that cannot be explained, such as the existence of dark matter in the universe, and it is expected that there will be a more basic theory.Among them, the supersymmetry theory is considered to be influential.In supersymmetry theory, a new elementary particle "supersymmetric particle" that is paired with all elementary particles of the Standard Model is predicted.

　The mass of supersymmetric particles is caused by "supersymmetry breaking", but Assistant Professor Okumura investigated in detail the supersymmetry breaking called modular mediation suggested by string theory, which is a candidate for quantum gravity theory.He discovered that the quantum mechanical correction from heavy elementary particles, which was previously thought to exist in the mass of superpartners, disappears under certain conditions.

　For example, a seesaw mechanism that explains the small mass of neutrinos predicts heavy right-handed neutrinos.It was predicted that this right-handed neutrino would give a quantum mechanical correction to the mass of muons and supersymmetric pairs of electrons, which would result in a muon-electron conversion process that exceeds the limits of the experiment in a wide range of theories.If a new property is established, this process will be suppressed, and models that have already been rejected, such as models based on a certain grand unified theory, will be revived and will be the subject of future experimental exploration.This new property can also affect various prophecies of supersymmetry theory.

Paper information:[Physical Review Letters] Hide and Seek with Massive Fields in Modulus Mediation