  We analyze in detail the LHC prospects at the center-of-mass energy of 14 TeV
for charged electroweakino searches, decaying to leptons, in compressed
supersymmetry scenarios, via exclusive photon-initiated pair production. This
provides a potentially increased sensitivity in comparison to inclusive
channels, where the background is often overwhelming. We pay particular
attention to the challenges that such searches would face in the hostile high
pile-up environment of the LHC, giving close consideration to the backgrounds
that will be present. The signal we focus on is the exclusive production of
same-flavour muon and electron pairs, with missing energy in the final state,
and with two outgoing intact protons registered by the dedicated forward proton
detectors installed in association with ATLAS and CMS. We present results for
slepton masses of 120--300 GeV and slepton-neutralino mass splitting of 10-20
GeV, and find that the relevant backgrounds can be controlled to the level of
the expected signal yields. The most significant such backgrounds are due to
semi-exclusive lepton pair production at lower masses, with a proton produced
in the initial proton dissociation system registering in the forward detectors,
and from the coincidence of forward protons produced in pile-up events with an
inclusive central event that mimics the signal. We also outline a range of
potential methods to further suppress these backgrounds as well as to enlarge
the signal yields.
