We like to arbitrarily split the six known quarks into three "light" and three "heavy": charm, beauty and top. They can never be found alone, but always in pairs (of a quark and an antiquark) or triplets.
There are actually very few particles made only of heavy quarks. The Bc meson is one. built of a charm quark and an anti-beauty quark. All particles containing a heavy quark decay very quickly, so how long would the Bc live? That's a tricky question for theorists trying to predict lifetimes and the very precise measurement of the LHCb collaboration gives them a benchmark to match.
Read more at http://lhcb-public.web.cern.ch/lhcb-public/#Bc
#physics #particlephysics #bquark #cquark
The mounting instructions are shown on the picture... The full story is in the technical design reports that can be found here : http://cds.cern.ch/search?ln=en&cc=Books+%26+Proceedings&p=lhcb+upgrade+technical+design+report&action_search=Search&op1=a&m1=a&p1=&f1=&c=Books+%26+Proceedings&c=&sf=&so=d&rm=&rg=10&sc=1&of=hb
More details are at http://lhcb-public.web.cern.ch/lhcb-public/#VELO
#silicon #science #particlephysics #pixeldetector
#research #cpviolation #physics #particlephysics #lhc
Another interesting feature is that the photons are polarised: they rotate to their left more often than to their right. That's at least what theory predicts. For the first time LHCb has been able to measure this polarisation effect.
In principle this is using tiny b quarks to repeat the historical experiment conducted in 1957 by Madame Wu, which allowed to first observe parity violation. You can make an experiment that tells reality from its mirror image. Hence left from right. That seems to be obvious, but it is far from trivial.
”LHCb operated with great success throughout LHC run 1 and has not been subject to any major intervention since its assembly in 2008. The current long shutdown offers a first opportunity for prolonged access, and hence an extensive programme of consolidation and maintenance work has been scheduled. This programme involves all general and detector related services, equipment and safety systems” writes Rolf Lindner, the LHCb Technical Coordinator. Read more at http://lhcb-public.web.cern.ch/lhcb-public/#LS1
The present "vertex locator" is already the detector coming closest to the #LHC beam (7mm). The pixel replacement will even get as close as 3.5mm.
#lhc #science #particlephysics #CERN #silicon
The picture below was taken on 18th December 2012, when Peter Higgs came to visit the .
Fourteen billion years ago, the Universe began with a bang. Crammed within an infinitely small space, energy coalesced to form equal quantities of matter and antimatter. But as the Universe cooled and expanded, its composition changed. Just one second after the Big Bang, antimatter had all but disappeared, leaving matter to form everything that we see around us — from the stars and galaxies, to the Earth and all life that it supports.