Speaker
Description
We propose a general framework that extends the Standard Model (SM) to the gauge group $SU(2k+3)\times Sp(2k)'\times U(1)_Y'\times Z_4$. The SM quarks are embedded in the fundamental multiplet of $SU(2k+3)$, $Sp(2k)'$ provides an extra technicolor (TC) sector, $U(1)_Y'$ helps reproduce the correct SM hypercharges, and, the discrete $Z_4$ forbids unwanted TC fermion mass terms. The strong CP problem is solved by two axions associated with the two non-Abelian groups. Both axions can be made heavy by the combined effects of small instantons and TC confinement. We scan the viable parameter space for different values of $k$ and present the resulting axion spectrum. The predicted masses lie well above the conventional QCD-axion window and open a richer set of phenomenological signatures for experimental searches.
