Leptonic mono-top from single stop production at the LHC

Abstract

Top squark (stop) can be produced via QCD interaction but also the electroweak interaction at the LHC. In this paper, we investigate the observability of the associated production of stop and chargino, pp→ t˜ 1χ˜ 1 ¯, in compressed electroweakino scenarios at 14 TeV LHC. Due to small mass splitting between the lightest neutralino (χ˜10) and chargino (χ˜1−), the single stop production can give the mono-top signature through the stop decay t˜1→tχ˜10. We analyze the leptonic mono-top channel of the single stop production and propose a lab-frame observable cos θbℓ to reduce the SM backgrounds. We find that such leptonic mono-top events from the single stop production can be probed at 2σ level at the HL-LHC if mt˜1<760 GeV and mχ˜10<150 GeV. Given a discovery of the stop and a measurement of the single stop production cross section, the stop mixing angle can also be determined from the single stop production at the HL-LHC. © 2017, The Author(s)