Speaker
Description
Particle physics models with Peccei-Quinn (PQ) symmetry breaking
as a consequence of supersymmetry (SUSY) breaking are attractive in that
they solve the strong CP problem with a SUSY DFSZ-like axion,
link the SUSY breaking and PQ breaking intermediate mass scales
and can resolve the SUSY $\mu$ problem with a naturalness-required
weak scale $\mu$ term whilst soft SUSY breaking terms inhabit the
multi-TeV regime as required by LHC sparticle mass limits and
the Higgs mass measurement.
On the negative ledger, models based on global
symmetries suffer a generic gravity spoliation problem.
We present two models based on the discrete $R$-symmetry
${\bf Z}_{24}^R$-- which may emerge
from compactification of 10-d Lorentzian spacetime in string theory--
where the $\mu$ term and dangerous proton decay and $R$-parity
violating operators are either suppressed or forbidden
while a gravity-safe PQ symmetry emerges as an accidental approximate
global symmetry leading to a solution to the strong CP problem
and a weak-scale/natural value for the $\mu$ term.
