Premises of signal beyond the Standard Model ? Run2 results from the ML based search of supersymmetric top

Abstract:
The LHC machine has delivered an unprecedented number of proton proton collisions at 13 TeV, so far our best window to look for phenomena beyond the Standard Model (SM) of particle physics. The search for the lightest supersymmetric top (stop) has been one of the most motivated search directions during the Run2 of the LHC.

In this talk, I will present the latest results of the CMS collaboration on the search for the stop decaying in four bodies. This decay mode, where the observable particles can be extremely soft, is very challenging, while motivated by measurements of the cold dark matter. The search is harnessed on a Machine Learning approach, which is adapted to different signal masses. I will scrutinize the observation of a 2.5 sigma excess of data versus the predicted SM background, and briefly cover perspectives for this search.