your question is meaningful. Indeed, the new scientist article wrote something only half true: it is true in fact that the Tevatron has higher chances to discover the Higgs when the latter has a small mass – therefore, between 115 GeV (the lower limit by direct experimental searches) and, say, 140 or 150 GeV. That is because we know that if the Higgs boson exists it is produced at a small rate at the Tevatron, and this rate goes down with increasing mass. Easier to see it at low mass therefore.

But this is only half of the story. In fact, the plot you see above does extend to 200 GeV, where CDF and D0 can indeed still search for the Higgs. Chances are not great there, since the rate is smaller; but on the other hand, the signature we know the Higgs displays if its mass is 160 GeV (say) is much more spectacular than if its mass is 120. In the former case it decays mostly to two W bosons, and backgrounds from competing processes are not large. In the latter case the signature is less clean and backgrounds are way larger.

To see a Higgs, the Tevatron must collect lots of data, probably all it can until 2009. By that time, the CMS and ATLAS experiments at the LHC (a similar accelerator, only 7 times more powerful) will also be looking for that particle – but they will have a reversed situation: no rate problems, but huge backgrounds at low mass, and they will be luckier if the Higgs is heavier.

So, in a nutshell, the Tevatron hopes that the Higgs is light – to have a chance to nail it down before the LHC does, even if there will be a time period when both facilities will be chasing the particle simultaneously. However, the Tevatron does have chances to find it nonetheless all the way to 180 GeV, as the plot above suggests.

To answer your last question: yes, although we have not found the higgs yet, we do know everything possible about it. We know how it decays, we know how frequently it is produced. We have Monte Carlo simulations which tell us what to look for and how to distinguish it from backgrounds. That is why we do know if we find one!

Cheers,
T.

Sorry for those stupid questions, I’m just curious

And carry on with your blog. Although I don’t understand everything I love your style of writing.

Cheers, Alex.

[1] http://www.newscientisttech.com/article/dn10909-the-higgs-boson-just-got-lighter.html