Interpreting a CMS excess in lljj+missing-transverse-momentum with the golden cascade of the minimal supersymmetric standard model

Allanach, Benjamin Christopher ; Kvellestad, Anders ; Raklev, Are (2015-06-29)


The CMS experiment recently reported an excess consistent with an invariant mass edge in opposite-sign same flavor (OSSF) leptons, when produced in conjunction with at least two jets and missing transverse momentum. We provide an interpretation of the edge in terms of (anti-)squark pair production followed by the ‘golden cascade’ decay for one of the squarks: q → χU2q → llq → χU1qll in the minimal supersymmetric standard model (MSSM). A simplified model involving binos, winos, an on-shell slepton, and the first two generations of squarks fits the event rate and the invariant mass edge. We check consistency with a recent ATLAS search in a similar region, finding that much of the good-fit parameter space is still allowed at the 95% confidence level (CL). However, a combination of other LHC searches, notably two-lepton stop pair searches and jets plus /pT , rule out all of the remaining parameter space at the 95% CL.