The MATHUSLA test stand

The rate of muons from LHC pp collisions reaching the surface above ATLAS interaction point is measured as a function luminosity and compared with expected rates decays W Z bosons b- c-quark jets. In addition, data collected during periods without beams circulating in provide measurement background cosmic ray inelastic backscattering that to simulation predictions. Data were recorded 2018 2.5 × 6.5 m3 active volume MATHUSLA test stand detector unit consisting two scintillator planes, one at top bottom, which defined trigger, six layers RPCs between them, grouped into three (x,y)-measuring separated by 1.74 m each other. Triggers selecting both upward-going tracks downward-going used.