  A new concept, the Triplet Track Trigger (TTT), is proposed for stand-alone
tracking at the first trigger level of the FCC-hh detector. The concept is
based on a highly scalable monolithic pixel sensor technology and uses a very
simple and fast track reconstruction algorithm that can be easily implemented
in hardware processors. The goal is to suppress the enormous pileup of ~1000
minimum bias collisions expected at the FCC-hh experiment and to identify the
hard-interaction vertex and the corresponding tracks as a basis for a trigger
decision. In the barrel region, the TTT consists of three closely stacked,
highly granular pixel detector layers at radii of ~1m. An extension of the TTT
to the endcap region increases the geometrical acceptance.
  We present full Geant4 simulations and reconstruction performance of a
modified FCC-hh reference tracker that includes TTT barrel and endcap detector
layers. The stacking of TTT layers results in excellent track purity, and the
large lever arm ensures very good momentum resolution. Additionally, sub-mm
$z$-vertex resolution is achieved, which allows for very efficient pileup
suppression. By reconstructing pileup suppressed track-jets, the primary vertex
of the hard interaction is successfully identified, even at a pileup rate of
$<\mu>=1000$ and at trigger level.
  The multi-jet signature, pp->HH->4b, is used as a showcase to study the
trigger performance of the TTT and compare it to an emulated calorimeter
trigger (calo-trigger). The TTT allows for significantly lower trigger
thresholds and higher trigger efficiencies than a calo-trigger. Furthermore,
the TTT is very robust against fluctuations in the pileup rate compared to the
calo-trigger. As a result, a significant increase in the statistics of di-Higgs
events is expected, in particular at low transverse momentum, where the
sensitivity to the Higgs self-coupling ($\lambda$) is the highest.
