  Many new physics scenarios predict multi-photon Higgs resonances. One such
scenario is the dark axion portal model. The primary decay chain that we study
is the Higgs to dark photon ($\gamma_D$) pairs that subsequently decay into a
photon ($\gamma$) and an axion-like particle ($a$). The axion-like particles
then decay into photon pairs. Hence, the signal is a six-photon Higgs decay:
$h\rightarrow \gamma_D\,\gamma_D\rightarrow 2\,\gamma 2\,a\rightarrow 6\gamma$.
However, depending on the relevant kinematics, the photons can become
well-collimated and appear as photon-jets (multiple photons that appear as a
single photon in the detector) or $\xi$-jets (non-isolated multi-photon signals
that do not pass the isolation criterion). These effects cause the true
six-photon resonance to appear as other multi-photon signals, such as two and
four photons. We classify the mass regions where two, four, and six-photon
resonances dominate. The four-photon signal is particularly interesting. These
events mainly occur when the photons from the axion-like particles are
collimated into photon-jets. The decay of the dark photon is then
$\gamma_D\rightarrow \gamma a\rightarrow \gamma+\gamma$-jet, which is an
apparent violation of the Landau-Yang theorem. We show that current
measurements of $h\rightarrow 2\gamma$ and searches for $h\rightarrow 4\gamma$
at the Large Hadron Collider (LHC) can limit ${\rm BR}(h\rightarrow
\gamma_D\gamma_D)\lesssim 10^{-3}$. This model also motivates new searches for
Higgs decays into six isolated photons or $\xi$-jets at the LHC. While there
are currently no dedicated searches, we show that many of the Higgs to six
isolated photons or $\xi$-jet events could pass two or three-photon triggers.
That is, new physics could be found by reanalyzing existing data. These
multi-photon signals provide excellent footing to explore new physics at the
LHC and beyond.
