Search for neutral color-octet weak-triplet scalar particles in proton-proton collisions at $ \sqrt{s}=8 $ TeV

A search for pair production of neutral color-octet weak-triplet scalar particles (Θ$^{0}$) is performed in processes where one Θ$^{0}$ decays to a pair of b quark jets and the other to a Z boson plus a jet, with the Z boson decaying to a pair of electrons or muons. The search is performed with data collected by the CMS experiment at the CERN LHC corresponding to an integrated luminosity of 19.7 fb$^{−1}$ of proton-proton collisions at $ \sqrt{s}=8 $ TeV. The number of observed events is found to be in agreement with the standard model predictions. The 95% confidence level upper limit on the product of the cross section and branching fraction is obtained as a function of the Θ$^{0}$ mass. The 95% confidence level lower bounds on the Θ$^{0}$ mass are found to be 623 and 426 GeV, for two different octo-triplet theoretical scenarios. These are the first direct experimental bounds on particles predicted by the octo-triplet model.. Authors: Khachatryan, Vardan [Yerevan Phys. Inst.]; Sirunyan, Albert M [Yerevan Phys. Inst.]; Tumasyan, Armen [Yerevan Phys. Inst.]; Adam, Wolfgang [Vienna, OAW]; Aşılar, Ece [Vienna, OAW] (ORCID:000000015680599X). DOE Contract: 89243024CSC000002. Subjects: 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; Experiment-HEP; Hadron-Hadron Scattering; exotics