We propose a search strategy using the LHC as a photon collider to open sensitivity to scalar lepton (slepton $\tilde{\ell}$) production with masses around 15 to 60 GeV above that of neutralino dark matter $\tilde��^0_1$. This region is favored by relic abundance and muon $(g-2)_��$ arguments. However, conventional searches are hindered by the irreducible diboson background. We overcome this obstruction by measuring initial state kinematics and the missing momentum four-vector in proton-tagged ultraperipheral collisions using forward detectors. We demonstrate sensitivity beyond LEP for slepton masses of up to 220 GeV for $ 15 \lesssim ��m(\tilde{\ell}, \tilde��^0_1) \lesssim 60$ GeV with 100 fb$^{-1}$ of 13 TeV proton collisions. We encourage the LHC collaborations to open this forward frontier for discovering new physics.

4 pages + bibliography, 3 figures