2015/11/30 by Kiwoon Choi, Sang Hui Im · 1 citation
Physics and Astronomy · #hep-ph #hep-th
paper · pdf · doi:10.1007/jhep01(2016)149
published as JHEP 1601:149,2016 · 20 pages, 2 figures; v2: a reference and related comment added
arxiv created 2016/01/29 · arxiv updated 2016/02/01
We discuss a scheme to implement the relaxion solution to the hierarchy problem with multiple axions, and present a UV-completed model realizing the scheme. All of the N axions in our model are periodic with a similar decay constant f well below the Planck scale. In the limit N≫ 1, the relaxion ϕ corresponds to an exponentially long multi-helical flat direction which is shaped by a series of mass mixing between nearby axions in the compact field space of N axions. With the length of flat direction given by Δϕ=2πf\rm eff ∼ eξN f for ξ=\cal O(1), both the scalar potential driving the evolution of ϕ during the inflationary epoch and the ϕ-dependent Higgs boson mass vary with an exponentially large periodicity of \cal O(f\rm eff), while the back reaction potential stabilizing the relaxion has a periodicity of \cal O( f). A natural UV completion of our scheme can be found in high scale or (mini) split supersymmetry (SUSY) scenario with the axion scales generated by SUSY breaking as f∼ √m\rm SUSYM_*, where the soft SUSY breaking scalar mass m\rm SUSY can be well above the weak scale, and the fundamental scale M_* can be identified as the Planck scale or the GUT scale.