Fermi National Laboratory

Volume 22  |  Friday, October 29, 1999  |  Number 21
In This Issue  |  FermiNews Main Page

Letter to the Editor

To the Editor of FERMINEWS:

Rajendran Raja It was with some amusement that I read the correspondence between yourself and the author of the article in the September 2nd issue of FAST, the electronic French review of advances in science and technology. This underscores the need for scientific precision when discussing these matters as can be seen from the enclosed plot taken from the conclusions of the Fermilab Run II workshop on Higgs.

us take the following plausible scenario that LEP does not discover the Higgs in its current run. It is widely expected in this case that they will be able to rule out standard model Higgs masses below 110 GeV/c2 at the 95% confidence level. (This means that they can be wrong with a probability of 5%. Most of this likelihood is concentrated at Higgs masses just below 110GeV/c2.)

As can be seen from the plot, in order for Fermilab to extend the Higgs mass lower limit beyond 110GeV/c2 at the 95% confidence level, an integrated luminosity of 0.7 - 0.9 fb-1 per experiment is needed, depending on what smoothing algorithm one uses on the plot. This is 7-9 times more data than has been obtained in Run I. If however, one is trying to make a discovery of a Higgs boson of mass 110 GeV/c2 , then more stringent standards of probability are required and to obtain a 5 standard deviation signal would require an integrated luminosity of 10 fb-1 per experiment, again depending on the smoothing algorithm. Recent versions of the Fermilab schedule show us receiving 15 fb-1 per experiment by the year 2007, so it is not unreasonable to conclude that 10 fb-1would be obtainable only by the year 2005. This era used to be designated as Run III, in previous versions of the Fermilab schedule, a document not noted for its precision. The bottom line is that depending on what one is talking about, extending the Higgs mass lower bound or making a discovery, both the French article and your response to it have merit!

Yours Sincerely,

Rajendran Raja Fermilab

last modified 10/29/1999   email Fermilab