From Fermilab Today: “Result of the Week – The Higgs boson: “Two b” or not “two b”
Fermilab continues to be a great source of strength in the U.S. Basic Research Community.
Thursday, July 12, 2012
“With the recent announcement of a new particle discovery by the LHC experiments, it seems very likely that the Higgs boson exists. So, we are finally done with the search for the Higgs boson, right? Not quite!
Now the question is: What kind of a Higgs boson is it?
The best-fit cross section times branching ratio (σWH + σZH) x Br(H → bb) as a function of Higgs mass. The dark-shaded region shows the 68 percent confidence level interval; the light-shaded region shows the 95 percent confidence level region; and the Standard Model prediction is shown as the smooth, falling curve with a narrow band indicating the theoretical uncertainty.No image credit.
Normally, when physicists talk about the Higgs boson, they are talking about the Standard Model Higgs boson, the simplest mechanism that allows for the masses of the particles in the Standard Model, where “simple” means that the mechanism only requires the Higgs boson – no additional particles required.
Recently, the CDF experiment submitted four papers to Physical Review Letters describing searches for the Higgs decay in the bb final state. Scientists search for the cases of the Higgs produced in association with a W boson, the Higgs produced in association with a Z boson, the Higgs produced in association with a W or Z and W/Z decays into invisible particles, and finally a combination of all three searches. The combined result is the most sensitive search to date for the Higgs decaying into two b quarks and, while not conclusive, the result shows slightly stronger hints for the Standard Model than expected. That is, the CDF search for the Higgs boson in the bb final state indicates that it might occur more often than predicted in the Standard Model. However the new result is also still consistent with the Standard Model within measurement uncertainties.”
See the full article here.