Search for microscopic black holes in pp collisions at sqrt(s) = 7 TeV

TL;DR

This paper reports a search for microscopic black holes in proton-proton collisions at 7 TeV, finding no evidence and setting new limits on their possible masses, with improved sensitivity over previous studies.

Contribution

It provides the first comprehensive search for microscopic black holes at 7 TeV with increased sensitivity and model-specific mass exclusion limits.

Findings

No excess above standard model backgrounds was observed.

Excluded semiclassical and quantum black holes below 3.8 to 5.3 TeV.

Excluded string balls below 4.6 to 4.8 TeV.

Abstract

A search for microscopic black holes in pp collisions at a center-of-mass energy of 7 TeV is presented. The data sample corresponds to an integrated luminosity of 4.7 inverse femtobarns recorded by the CMS experiment at the LHC in 2011. Events with large total transverse energy have been analyzed for the presence of multiple energetic jets, leptons, and photons, which are typical signals of evaporating semiclassical and quantum black holes, and string balls. Agreement with the expected standard model backgrounds, which are dominated by QCD multijet production, has been observed for various combined multiplicities of jets and other reconstructed objects in the final state. Model-independent limits are set on new physics processes producing high-multiplicity, energetic final states. In addition, new model-specific indicative limits are set excluding semiclassical and quantum black holes with masses below 3.8 to 5.3 TeV and string balls with masses below 4.6 to 4.8 TeV. The analysis has a substantially increased sensitivity compared to previous searches.