Saturday, September 8, 2012

Is this test of the Standard Model impressive?

A week ago we had an interesting physics colloquium The Higgs Boson at the Large Hadron Collider by Elizabetta Barberio, who works in the ATLAS detector collaboration.

It was nice to hear a talk about the Higgs boson which simply discussed the physics and the actual experimental results, without any hype.

To me one of the most interesting and impressive figures shown in the talk actually had nothing to do with the Higgs! I found it here on the CERN website.

It shows the measured cross sections for the production of different particle products (horizontal scale).
Note the vertical scale varies by four orders of magnitude.
Basically, it shows that the results from the ATLAS detector are consistent with the Standard Model.

One thing I would like to know is how many independent parameters (coupling constants) are involved in determining these cross sections from the Standard Model?
Is the agreement between experiment and theory impressive? Or are there so many parameters in the Standard Model that this plot is really just saying what those parameters are? But, all the cross sections can't be independent of one another.

No comments:

Post a Comment