Center for Theoretical Physics of the Universe (CTPU)

Fast-Rolling Relaxion

by Dr. Yutaro Shoji (Kobayashi-Maskawa Institute for the Origin of Particle and the Universe)

Wednesday, 28 August 2019 from to (Asia/Seoul)
at CTPU Seminar Room
Fourth floor IBS Building, 55, Expo-ro, Yuseong-gu, Daejeon, Korea, 34126

The negative results at the Large Hadron Collider imply that the scale of new physics is higher than TeV scale. If it is the case, it is preferable to have a mechanism to explain the hierarchy between the new scale and the electroweak scale. The relaxionmechanism, proposed by P. W. Graham, D. E. Kaplan, and S. Rajendran, is a dynamical solution to the hierarchy problem. We point out that the tunneling phase of the relaxation requires a huge number of e-folds of inflation and could cause fine-tuning problems in inflation sector. We found a new mechanism similar to theirs, which overcomes the problem, is realized in a more generic setup, and enhances the testability at colliders.