Painting the full picture of the Higgs

With all analysis channels updated to use the full Tevatron Run II data set, DZero enhances the picture of the newly observed Higgs-like particle and tests its consistency with the Standard Model.

Determining whether the new particle observed last year is the Standard Model Higgs boson requires a look at the big picture. The Higgs boson plays an important role in the Standard Model, giving mass to quarks, charged leptons and the weak force carriers, but it is not the only possible explanation for why those particles have mass. Every property of this new particle must be measured to verify that it is a Standard Model Higgs boson and not evidence of exotic new physics. Some of the most important properties to confirm are its preferences for decaying into other particles, a task no single analysis can perform independently.

Last July, the DZero collaboration published results based on the full Tevatron Run II data set for searches focused on the Higgs boson decaying to bottom quarks. In combination with the CDF collaboration, those results contributed to showing evidence for a Higgs-like particle decaying into a pair of bottom quarks. The same month, LHC experiments reported the discovery of a Higgs-like particle.

Since CDF and DZero presented their results, analysis teams have continued their endeavors to update the results for each Higgs decay channel to make use of the full data set, improving the methodology for each analysis along the way. These efforts have been completed, and the full data set is now used for nearly all channels in a new combination of Higgs boson studies at DZero.

There is an overall excess of data that is consistent with the production of a 125-GeV mass Higgs boson. Each of the four main decay channels considered contributes to this excess and favors the Standard Model Higgs boson hypothesis. The combined analysis also considered exotic models where the Higgs disfavors decaying to quarks and leptons or is influenced by the existence of an undiscovered fourth generation of quarks. These results are the culmination of many years of effort by the DZero collaboration and, once combined with Higgs boson results from CDF, will help further enhance the picture of the Higgs boson.

Mike Cooke

This result is the culmination of many years of work by the DZero collaboration.