## Tuesday, March 28, 2006 ... //

### B-mesons and supersymmetry?

I am usually very skeptical about statements that new physics has been discovered through high-precision experiments; especially about the precise identity of the new physics - and this case is no exception. Five years ago, we have heard a similar story about the discovery of supersymmetry in Brookhaven. It went away after some signs in theoretical calculations of some two-loop diagrams were corrected.

Nevertheless, you should still know that the D0 detector team at the Tevatron at Fermilab is submitting a paper about the

to Physical Review Letters in which they argue that their measurement is "the first tangible evidence for supersymmetry" (at least in the article above they say so). I, for one, will only believe that SUSY is discovered once the things are so clear that Michal Fabinger pays me those 1,000 dollars which will probably not happen in 2006 if ever.

Moreover, a reader points out that the measured frequency is exactly what is predicted by the Standard Model, which would make the comment in the article to be just the opposite of the truth. I am not able to verify the exact number.

The B_s meson is a neutral bound state of a bottom-quark and a strange-antiquark that can, much like the neutral K meson, oscillate in between this state and its antiparticle. The frequency of oscillations is, according to the experiments, 19 trillion Hertz plus minus 10 percent at 90 percent confidence level. These oscillations measure violations of discrete symmetries, especially the CP symmetry.

The article also explains that the physicists only accept a statement as a discovery once the confidence level is 99.99995% which you should view as an explanation why I find various tests about the correlations of XY and health (or climate) to be junk science.

The spokesman of the competing CDF detector group explains that the CDF people are jealous but they are better anyway. With a higher sensitivity, they have a more chance to make the discovery by looking at a corresponding dataset. Stay tuned but don't expect miracles.