Setting Limits on the Higgs Mass
If there is a Higgs boson
the heavier it is, the less
Suppose that the Higgs mass is 80 GeV,
and suppose we expect 4.7 Higgs events.
We perform the experiment and observe 1.
The Poisson probability that 4.7 will fluctuate down to 1 is 5%:
There may still be an 80 GeV Higgs boson,
but it is only probable at the 5% and the observed Higgs
candidate is most probably a Background event.
A Higgs heavier than 80 Gev
is excluded at the 95% Confidence Level.