  Galaxy cluster mergers that exhibit clear dissociation between their dark
matter, intracluster gas, and stellar components are great laboratories for
probing dark matter properties. Mergers that are binary and in the plane of the
sky have the additional advantage of being simpler to model, allowing for a
better understanding of the merger dynamics. We report the discovery of a
galaxy cluster merger with all these characteristics and present a
multiwavelength analysis of the system, which was found via a search in the
redMaPPer optical cluster catalog. We perform a galaxy redshift survey to
confirm the two subclusters are at the same redshift (0.541, with $368\pm519$
km s$^{-1}$ line-of-sight velocity difference between them). The X-ray
morphology shows two surface-brightness peaks between the BCGs. We construct
weak lensing mass maps that reveal a mass peak associated with each subcluster.
Fitting NFW profiles to the lensing data, we find masses of $M_{\rm
200c}=36\pm11\times10^{13}$ and $38\pm11\times10^{13}$ M$_\odot/h$ for the
southern and northern subclusters respectively. From the mass maps, we infer
that the two mass peaks are separated by $520^{+162}_{-125}$ kpc along the
merger axis, whereas the two BCGs are separated by 697 kpc. We also present
deep GMRT 650 MHz data to search for a radio relic or halo, and find none.
Using the observed merger parameters, we find analog systems in cosmological
n-body simulations and infer that this system is observed between 96-236 Myr
after pericenter, with the merger axis within $28^{\circ}$ of the plane of the
sky.
