"Oh Wind, if Winter comes, can Spring be far behind ?"
Good old Shelley inspired me to start today's article with the above verse, taken from his magnificent "Ode to the West Wind". With the weather we are experiencing these days in Geneva and northern Italy, I found it a relieving thought...
So, winter conferences are over, and summer ones are still far away. This is therefore a nice moment to try an assessment on the quality of the results that the two competing CERN experiments have produced on the study of the Higgs boson. Why ? Because we are not going to have to change our conclusions in a short time scale caused by a result about to be published.
How to compare the results
Calibration does not always mean fixing a device, it sometimes means adjusting to solve a problem. In the early years of America, the famous Kentucky longrifles that conquered the frontier (and some British) had fixed sights. Since they couldn't be adjusted, frontiersmen - Kentucky was part of "The West" then - would adjust for wind, elevation and range by experience. If their shot was hitting low and left, they aimed high and right. Inference helped them get a better result.
The results of a third-party investigation of Rossi's E-CAT reactor have appeared on the Cornell arxiv
, and the conclusions of the tests are at the very least startling:
"New Physics can appear at any moment but it is now conceivable that no new physics will show up at the LHC"
Guido Altarelli, LHC Nobel Symposium, May 15th 2013
It is funny reading the above quote if you are one who "conceived" that the LHC could find no new physics 7 years ago, as demonstrated by where I put my money...
Hofstadter's Butterfly, a complex pattern of the energy states of electrons that resembles a butterfly, has appeared in physics textbooks as a theoretical concept of quantum mechanics for nearly 40 years but had never been directly observed - until now.
Finally the decay of Higgs bosons to b-quark pairs is emerging from LHC data, too.
Supersymmetry, the extension of the Standard Model of particle physics that was once sold as an almost certain discovery that the LHC experiments would bump into upon starting to collect proton-proton collisions, is not in a very healthy situation these days.
In 1992 the top quark had not been discovered yet, and it did not make much sense for the CDF collaboration to have a full meeting devoted solely to it; rather, analyses targeting the search of the top quark were presented at a meeting which dealt with both bottom and top quarks. This was called back then "Heavy Flavour meeting".
While school-age models of atomic nuclei show them as being spherical, like a basketball, they are more like the shape of a football.
Yet for some particular combinations of protons and neutrons, nuclei can also assume very asymmetric shapes, like a pear, where there is more mass at one end of the nucleus than the other.
With the Higgs boson in the bag, the game called "global fit" that particle physicists have been playing for a couple of decades has changed significantly. The knowledge of the Higgs boson mass provided by the measurements obtained by the ATLAS and CMS experiments, added to dozens of other measurements of critical observable properties of subatomic particles that have been measured at LEP/SLC, LEPII, the Tevatron, and the LHC itself, allow us to constrain some of the fundamental parameters of the Standard Model more than direct experimental determinations do.
But what the heck is a global fit ?