Saturday, 19 November 2011

New Physics?

First hints of "the new physics"?  At least these results are becoming more public but still not at the statistical level where they become official, however news of CP violation at this magnitude is extremely interesting. First the BBC's report on this (readable by the layman):

LHC reveals hints of 'new physics' in particle decays
15 November 2011 Last updated at 12:18 GMT
By Jason Palmer Science and technology reporter, BBC News

Large Hadron Collider researchers have shown off what may be the facility's first "new physics" outside our current understanding of the Universe. Particles called D-mesons seem to decay slightly differently from their antiparticles, LHCb physicist Matthew Charles told the HCP 2011 meeting on Monday.  The result may help explain why we see so much more matter than antimatter. The team stresses that further analysis will be needed to shore up the result. At the moment, they are claiming a statistical certainty of "3.5 sigma" - suggesting that there is less than a 0.05% chance that the result they see is down to chance. The team has nearly double the amount of data that they have analysed so far, so time will tell whether the result reaches the "five-sigma" level that qualifies it for a formal discovery

and the report from CERN itself:

Charming surprise
The Bulletin - Issue No. 45-46/2011 - Monday 7 November 2011

The CP violation in charm quarks has always been thought to be extremely small. So, looking at particle decays involving matter and antimatter, the LHCb experiment has recently been surprised to observe that things might be different. Theorists are on the case.

The study of the physics of the charm quark was not in the initial plans of the LHCb experiment, whose letter “b” stands for “beauty quark”. However, already one year ago, the Collaboration decided to look into a wider spectrum of processes that involve charm quarks among other things.

The LHCb trigger allows a lot of these processes to be selected, and, among them, one has recently shown interesting features. Other experiments at b-factories have already performed the same measurement but this is the first time that it has been possible to achieve such high precision, thanks to the huge amount of data provided by the very high luminosity of the LHC. “We have observed the decay modes of the D0, a particle made up of a charm quark plus a u antiquark”, explains Pierluigi Campana, LHCb Spokesperson. “In particular, we have studied and combined the decay rates of the D0 and its antiparticle. According to the theory of the Standard Model, we should have measured a very small value of a parameter known as Delta ACP that is calculated using these decay rates and is related to the properties of matter and antimatter. We found that Delta ACP is around 0.8% instead of the predicted 1‰ (or less). Although making precise evaluations in processes involving charm quarks is difficult, the Delta ACP parameter appears to be much higher than expected”.

Finally, Ars Technica has an overall write-up on the FTL neutrinos, CP violation and Higgs:

It has been a busy week in the world of particle physics, with attention focused on the home of the LHC: CERN. This year, the LHC generated five inverse femtobarns worth of data—nearly half the amount generated during the entire lifetime of the Tevatron—before shutting down the proton program a few weeks ago. From now until its scheduled winter shutdown, the LHC will be doing lead ion collisions to examine the quark-gluon interactions that dominated the Universe immediately after the Big Bang.

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