MUSiC: a model-unspecific search for new physics in proton–proton collisions at $$\sqrt{s} = 13\,\text {TeV} $$

Abstract

Results of the Model Unspecific Search in CMS (MUSiC), using proton–proton collision data recorded at the LHC at a centre-of-mass energy of 13$$\,\text {TeV}$$ TeV , corresponding to an integrated luminosity of 35.9$$\,\text {fb}^{-1}$$ fb - 1 , are presented. The MUSiC analysis searches for anomalies that could be signatures of physics beyond the standard model. The analysis is based on the comparison of observed data with the standard model prediction, as determined from simulation, in several hundred final states and multiple kinematic distributions. Events containing at least one electron or muon are classified based on their final state topology, and an automated search algorithm surveys the observed data for deviations from the prediction. The sensitivity of the search is validated using multiple methods. No significant deviations from the predictions have been observed. For a wide range of final state topologies, agreement is found between the data and the standard model simulation. This analysis complements dedicated search analyses by significantly expanding the range of final states covered using a model independent approach with the largest data set to date to probe phase space regions beyond the reach of previous general searches.

Highlights and perspectives from the CMS experiment

“…Searches for the production of new heavy particles promptly decaying to pairs of leptons [40] or vector bosons [41] with the full Run-2 data set, have been performed. In the latter case, one of the bosons is a W decaying leptonically, while the other one (W, Z or H) is boosted and detected as a merged jet with substructures.…”

“…Many other searches are exploiting the novel boosted boson or top-quark detection techniques (for instance [17,20,42]). CMS has also developed a systematic search for deviations from the standard model predictions [41] in several hundred final states and kinematic distributions, in events containing at least one lepton.…”

ATLAS + CMS searches beyond inclusive resonances in leptonic final states

“…CMS categorised events in about 60 classes [26] based on the number of light leptons and light jets. Data collected during 2016 corresponding to an integrated luminosity of 35.9 fb −1 is used.…”

Anomaly detection with convolutional Graph Neural Networks

“…One method of searching for the presence of new BSM interactions is attempting to detect anomalies in otherwise well-understood and abundant collider data [2][3][4][5][6][7][8][9][10]. Hard jets produced primarily via QCD-mediated interactions at hadron colliders are a well-known laboratory for such strategies and their phenomenology has seen considerable development over the past decade [11].…”