KEK Theory Seminar/Mr.Daido

Start2018/01/16(Tue)11:00 AM
End2018/01/16(Tue)12:00 PM
VenueKenkyu-Honkan 3F, Seminar Room
TitleEnhanced axion-photon coupling in a GUT with hidden photon
SpeakerMr. Ryuji Daido(Tohoku University)
ContactKiyoharu Kawana/



We first review current status of QCD axion searches, which generically

rely on interaction between the axion and SM photon.

Next, we show that the axion-photon coupling is modified in the presence

of massless hidden photon which has kinetic mixing with the SM photon. If

the kinetic mixing and hidden gauge coupling are \mathcal{O}(1), the

axion-photon coupling becomes several tens of times larger.

Finally, we consider QCD axion in SU(5) GUT with massless hidden photon.

Gauge coupling unification is determined by the size of kinetic mixing

only, and requires relatively large kinetic mixing, which is naturally

generated when hidden gauge coupling is large. We find enhancement factor

of axion-photon coupling is about 20 in our model.