The neutral B mesons, and , spontaneously transform into their own antiparticles and back. This phenomenon is called
flavor oscillation. The existence of neutral B meson oscillations is a fundamental prediction of the
Standard Model of
particle physics. It has been measured in the – system to be about , and in the – system to be measured by
CDF experiment at
Fermilab. A first estimation of the lower and upper limit of the – system value have been made by the
DØ experiment also at
Fermilab. On 25 September 2006,
Fermilab announced that they had claimed discovery of previously-only-theorized meson oscillation. According to Fermilab's press release: This first major discovery of Run 2 continues the tradition of particle physics discoveries at Fermilab, where the bottom (1977) and top (1995) quarks were discovered. Surprisingly, the bizarre behavior of the (pronounced "B sub s") mesons is actually predicted by the Standard Model of fundamental particles and forces. The discovery of this oscillatory behavior is thus another reinforcement of the Standard Model's durability ... CDF physicists have previously measured the rate of the matter–antimatter transitions for the meson, which consists of the heavy bottom quark bound by the strong nuclear interaction to a strange antiquark. Now they have achieved the standard for a discovery in the field of particle physics, where the probability for a false observation must be proven to be less than about 5 in 10 million For CDF's result the probability is even smaller, at 8 in 100 million Ronald Kotulak, writing for the
Chicago Tribune, called the particle "bizarre" and stated that the meson "may open the door to a new era of physics" with its proven interactions with the "spooky realm of antimatter". 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 with larger data samples have suggested no significant deviation from the Standard Model. == Rare decays ==