This plot shows the observed and expected upper limits at the 95 percent credibility level on the fraction of exotic boson production for two cases (spin zero with negative parity and spin two with positive parity). A signal scale of one corresponds to the Standard Model. The Higgs boson caused a lot of excitement when the ATLAS and CMS collaborations announced its discovery in 2012. Everyone was bursting with questions: How much does it weigh? How is it made? How…
Best-fit signal strengths μ for two cases. Left: the Standard Model versus graviton-like boson (spin 2, positive parity) versus the Standard Model Higgs boson (spin 0, positive parity). Right: the pseudoscalar boson (spin 0, negative parity) versus the Standard Model Higgs boson. Since the discovery of the Higgs boson at CERN and the three-standard-deviation excess seen by the CDF and DZero experiments here at Fermilab, the experimental community has been focusing on measuring the properties of this new particle. It’s…
This diagram shows the s-channel single-top quark production mechanism sought in this analysis, which selects signal events in which the lepton is not identified. In collisions of high-energy beams, new, heavy particles are usually produced in pairs: a matching antiparticle for every particle. That’s the case for the bottom quark and the top quark, both discovered at Fermilab. But every now and then, the weak force is responsible for the collision, and so particles can be transmuted from one kind…