[Seminars] Reminder: Particle theory seminar today

[Emmanuel Stamou]

DATE: WEDNESDAY November 1, 2017

TIME: 1:30P.M.

LOCATION: PRC 3rd Floor Common Space

SPEAKER: Kiel Howe, Fermilab

TITLE: "Factoring the Strong CP Problem"

ABSTRACT:  We present a mechanism to solve the strong CP problem by embedding 
QCD in a SU(3)^N product gauge group at high energies. The simplest version of 
this mechanism realizes a heavy QCD axion by embedding QCD in the diagonal 
subgroup of a SU(3)xSU(3) gauge group at a scale M~10^14 GeV. The vacuum is 
naturally aligned to ensure θ=0 at low energies, and the axions in the theory 
have masses much larger than for the standard QCD axion. Unlike other heavy 
QCD axion models, there are no discrete Z2 symmetries or mirror copies of SM 
particles. Another realization of this mechanism can revive the massless up-
quark solution to the strong CP problem with a flavorful embedding of the SM 
fermions in a SU(3)xSU(3)xSU(3) gauge group at a scale M~100 TeV.