Axion clockworks from heterotic M-theory: the QCD-axion and its ultra-light companion
arXiv:1906.11851 · doi:10.1007/JHEP10(2019)159
Abstract
A previously discussed clockwork mechanism within heterotic M-theory is applied to its axion landscape. We identify a unique candidate for a QCD-axion with a decay constant in the preferred "axion window" around GeV. It is accompanied by at least one ultra-light axion that couples predominantly to hidden sector gauge groups.
1+23 pages; v2: references added, version published in JHEP