Neutral B meson oscillations (or
oscillations) is one of the manifestations of the neutral particle oscillation, a fundamental prediction of the Standard Model of particle physics. It is the phenomenon of B mesons changing (or oscillating) between their matter and antimatter forms before their decay. The
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.
Excess of matter over antimatter
The Standard Model predicts that regular matter
s mesons are slightly favored in these oscillations over their antimatter counterpart, making strange B mesons of special interest to particle physicists. The observation of the
mixing phenomena led physicists to propose the construction of B-factories in the early 1990s. They realized that a precise
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
(4S) resonance which is just above the threshold for decay into two B mesons.
On 14 May 2010, physicists at the Fermi National Accelerator Laboratory reported that the oscillations decayed into matter 1% more often than into antimatter, which may help explain the abundance of matter over antimatter in the observed Universe. However, more recent results at LHCb in 2011 and 2012 with larger data samples have demonstrated no significant deviation from the Standard Model prediction of very nearly zero asymmetry.
- A New Clue to Explain Existence
- "LHCb detector causes trouble for supersymmetry theory". Ars Technica. August 29, 2011.
- LHCb collaboration (2014). "Measurement of the flavour-specific CP-violating asymmetry as
sl in B0
s decays". Physics Letters B. 728: 607–615. Bibcode:2014PhLB..728..607A. doi:10.1016/j.physletb.2013.12.030.
- 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