B meson

From Wikipedia, the free encyclopedia

B mesons are mesons composed of a bottom antiquark and either an up (B⁺), down (B⁰), strange (B0s) or charm (B+c) quark, but they are not to be confused with bottomonium which composed of a bottom quark and bottom antiquark. Each B meson has an antiparticle that is composed of a bottom quark and an up (B⁻), down (B⁰), strange (B0s) or charm antiquark (B−c) respectively. The neutral B mesons, B⁰ and B0s, spontaneously transform into their own antiparticles and back. This phenomenon is called flavor oscillation and has been measured in the B⁰/B⁰ system to be about 0.496 ps^-1[1], and in the B0s/B0s system to be 17.77±0.12 ps^-1.^[2]

Particle	Symbol	Anti-particle	Quark Makeup	Spin and parity	Rest mass MeV/c²	S	C	B	Mean lifetime ps
B meson	B+	B−	ub	Pseudoscalar	5279.13(31)	0	0	+1	1.638(11)
B meson	B0	B0	db	Pseudoscalar	5279.50(33)	0	0	+1	1.530(9)
Strange B meson	B0s	B0s	sb	Pseudoscalar	5366.1(6)	−1	0	+1	1.437(31)
Charmed B meson	B+c	B−c	cb	Pseudoscalar	6286(5)	0	+1	+1	0.46(7)

[edit] References

1. ^ http://repository.ubn.ru.nl/bitstream/2066/26242/
2. ^ A. Abulencia et al., CDF Collaboration, Phys. Rev. Lett. 97 242003 (2006).

[edit] External links

• W.-M. Yao et al. (Particle Data Group), J. Phys. G 33, 1 (2006) and 2007 partial update for edition 2008 (URL: http://pdg.lbl.gov)