2019/09/30 by Tony Gherghetta, Joern Kersten, Keith Olive +1 · 1 citation
Physics and Astronomy · #hep-ph
paper · pdf · doi:10.1103/physrevd.100.095001
published as Phys. Rev. D 100, 095001 (2019) · 20 pages + references; v2: added references, expanded discussion of non-Abelian dark sector; matches published version except for the title
arxiv created 2019/11/20 · arxiv updated 2019/11/21
We consider both "bottom-up" and "top-down" approaches to the origin of gauge kinetic mixing. We focus on the possibilities for obtaining kinetic mixings ε which are consistent with experimental constraints and are much smaller than the naive estimates (ε∼ 10-2 - 10-1) at the one-loop level. In the bottom-up approach, we consider the possible suppression from multi-loop processes. Indeed we argue that kinetic mixing through gravity alone, requires at least six loops and could be as large as ∼ 10-13. In the top-down approach we consider embedding the Standard Model and a U(1)X in a single grand-unified gauge group as well as the mixing between Abelian and non-Abelian gauge sectors.