Search for s channel single top quark production in pp collisions at sqrt(s) = 7 and 8 TeV

Understand

A search is presented for single top quark production in the s channel in proton-proton collisions with the CMS detector at the CERN LHC in decay modes of the top quark containing a muon or an electron in the final state.

• The signal is extracted through a maximum-likelihood fit to the distribution of a multivariate discriminant defined using boosted decision trees to separate the expected signal contribution from background processes.
• The analysis uses data collected at centre-of-mass energies of 7 and 8 TeV and corresponding to integrated luminosities of 5.1 and 19.7 inverse femtobarns, respectively.
• The measured cross sections of 7.1 +/- 8.1 pb (at 7 TeV) and 13.4 +/- 7.3 pb (at 8 TeV) result in a best fit value of 2.0 +/- 0.9 for the combined ratio of the measured and expected values.