Search for Higgs boson production in association with a single top quark at the CMS experiment

Higgs boson production in association with a single top quark (tH) is a very rare process with a production cross section of about one tenth of the production cross section of the associated production of a top quark pair and a Higgs boson ($t\overline{t}$H). In contrast to $t\overline{t}$H production, it is sensitive not only to the amplitude but also to the relative sign of the top-Higgs and W-Higgs couplings. This presentation will focus on the channel with the Higgs boson decaying into a pair of bottom quarks ($b\overline{b}$). In order to obtain event specific object variables, a jet-quark assignment is implemented under two signal and one background hypothesis. Jointly with global variables, the object variables are used to discriminate between signal and background events using boosted decision trees (BDT). Additionally, a control region dominated by dileptonic top quark pair production events is used to constrain uncertainties on the flavor composition of additional jets. Finally, the BDT outputs of the dileptonic and the signal regions of the $b\overline{b}$ channel are fitted collectively with the multilepton and diphoton decay channels to obtain limits on several coupling scenarios and tH production. Furthermore, a simultaneous fit for tH and $t\overline{t}$H signal strength is performed.