Measurement of the differential tt̄ cross section in the boosted all-hadronic channel for the CMS experiment at the LHC at √ s = 8TeV

[摘要] The first measurement of the differential tt̄ cross section at using 19.7 fb −1 of all-jet events with boosted high-p T top quark jets collected by the CMS detector at √s =8 TeV is presented. A boosted top jet is one in which the subjets have merged. Adata-driven method is used to calculate the standard model background dominated by QCD multijet production. The tt̄ cross section is extracted in bins of measured leading top quark p T using a binned likelihood fit of the invariant mass distribution oftop jet candidates. The tt̄ cross section as a function of measured leading top quark pT is then unfolded to parton-level in order to facilitate comparison with theory. This is the first measurement of the differential tt̄ cross secton in the boosted regime inthe all-jet channel at √s = 8 TeV.

[发布机构] Johns Hopkins University

[效力级别] cross section

[关键词] Top quark;cross section;LHC;CERN;pT;transverse momentum;boosted;jet;Physics