利用緊湊渺子線圈搜尋第四世代下型夸克

Results are presented from a search for heavy bottom-like quarks, pair-produced in pp collisions at a center of mass energy of 7 TeV, undertaken with the CMS experiment at the LHC. The b0 quarks are assumed to decay exclusively to tW. The pair production process of b0 can be identified by its distinctive signatures of three leptons or two leptons of same charge, and at least one b-quark jet. Using a datasample corresponding to an integrated luminosity of 4.9 fb−1, observed events are compared to the standard model background predictions, and the existence of b0 quarks having masses below 611 GeV is excluded at 95% confidence level.