  We investigate the scalar and pseudoscalar spectrum of the $SU(2)$ gauge
theory with $N_f=2$ flavours of fermions in the fundamental representation
using non perturbative lattice simulations. We provide first benchmark
estimates of the mass of the lightest $0(0^{+})$ ($\sigma$), $0(0^{-})$
($\eta'$) and $1(0^+)$ ($a_0$) states, including estimates of the relevant
disconnected contributions. We find $m_{a_0}/F_{\rm{PS}}= 16.7(4.9)$,
$m_\sigma/F_{\rm{PS}}=19.2(10.8)$ and $m_{\eta'}/F_{\rm{PS}} = 12.8(4.7)$.
These values for the masses of light scalar states provide crucial information
for composite extensions of the Standard Model from the unified Fundamental
Composi te Higgs-Technicolor theory \cite{Cacciapaglia:2014uja} to models of
composite dark matter.
