The existence of neutral B meson oscillations (or B–B oscillations) is a fundamental prediction of the Standard Model of particle physics. The theory predicts that the neutral B mesons will change (or oscillate) between their matter and antimatter forms before their decay.

Contents 1 B-factories 2 Bs oscillations 3 See also 4 References 5 External links

[edit] B-factories

The observation of the B–B mixing phenomena led physicists to propose the construction of B-factories in the early 1990s. They realized that a precise B–B oscillation measure could pin down the unitarity triangle and perhaps explain the excess of matter over antimatter in the universe. To this end construction began on two B-factories in the late nineties, one at the Stanford Linear Accelerator Center (SLAC) in California and one at KEK in Japan. These B-factories, BaBar and Belle, were set at the {{SubatomicParticle|Upsilon(4S) resonance which is just above the threshold for decay into two B mesons. After several years they confirmed that the standard model was correct to high precision in this area.

[edit] B_s oscillations

The B_s meson can exist as either a bound state of a strange antiquark and a bottom quark, or a strange quark and bottom antiquark. The oscillations in the neutral B sector are analogous to the phenomena that produces long and short-lived neutral kaons. B_s mixing was observed by the CDF experiment at Fermilab in 2006.

[edit] See also

• Kaon
• Strange B meson

[edit] References

• Paper describing the discovery of B-meson mixing by the ARGUS Collaboration
• Fermilab press release from April 2006
• September 2006 press release regarding 5 sigma discovery

[edit] External links

• BaBar Public Homepage
• Belle Public Homepage