The high cross-section for the production of b quarks at the Tevatron hadron collider make it an ideal place to search for rare B meson species and very low branching fraction decay modes of the more common B mesons. This paper reports the recent discovery of the Bc meson by the CDF collaboration. It also discusses the observation of rare B meson final states involving [psi](2S) mesons and searches for ultra-rare decays such as B [yields] [mu][sup +][mu][sup -].

We report on the search for B°{sub s}→??−, B°{sub d}→?+?− decays and b→ s?+?− transitions in exclusive decays of B mesons using the CDF II detector at the Fermilab Tevatron Collider. Using 2 fb−1 of Run II data we find upper limits on the branching fractions?(B°{sub s}→?+?−)

Rare B meson decays are an excellent probe for beyond the Standard Model physics. Two very sensitive processes are the B{sub s, d}° →??− and b → s?+?− decays. We report recent results at a center of mass energy of √s = 1.96 TeV from the CDF II and D0 collaborations using between 3.7 fb−1 and 6.9 fb−1 taken during Run II of the Fermilab Tevatron Collider.

In this proceeding we report the most recent results from the CDF and D0 collaborations on the rare decays of b-mesons. The presented results show a new D0 limit for?(B{sub s}° →??−) that represent the best single measurement on this mode so far, an update of the?(B{sub s}° →??) with, for the first time, an angular analysis on the final state, a new measurement of the?(B° → K*°?+?−) and?(B+ → K+?+?−) with an interesting measurement on the forward-backward asymmetry for those channels and the first observation of the?(B{sub s}° →??+?−).

The authors search for b → s??− transitions in B meson (B+, B°, or B{sub s}°) decays with 924 pb−1 of p{bar p} collisions at √s = 1.96 TeV collected with the CDF II detector at the Fermilab Tevatron. They find excesses with significances of 4.5, 2.9, and 2.4 standard deviations in the B+ →?+?−K+, B° →?+?−K*(892)°, and B{sub s}° →?+?−? decay modes, respectively. Using B → J/?h (h - K+, K*(892)°,?) decays as normalization channels, they report branching fractions for the previously observed B+ and B° decays as normalization channels, they report branching fractions for the previously observed B+ and B° decays,?(B+ →?+?−K+) = (0.59 ± 0.15 ± 0.04) x 10−6, and?(B° →?+?−K*(892)°) = (0.81 ± 0.30 ± 0.10) x 10−6, where the first uncertainty is statistical, and the second is systematic. These measurements are consistent with the world average results, and are competitive with the best available measurements. They set an upper limit on the relative branching fraction?(B{sub s}°→?+?−?)/?(B{sub s}°→J/??)