This page summarizes an analysis which searches for the rare decays * Bs → μμ *
and * Bd → μμ *. These results were finalized on
April 7th, 2005 and correspond to a dataset of 364 pb-1. A PRL paper on the analysis can be found at
hep-ex/0508036.

D0 Run 2, BR(

There are various extensions to the SM predict an enhancement of this branching ratio by 1 to 3 orders of magnitude. Many of these models are, presently, theoretically very interesting since some have some relevance to the deviation of the muon (g-2), neutrino oscillations, and dark matter/dark energy results.

Here's a plot from
(hep-ph/0108037),
which shows BR(* Bs → μμ *) in the (M0,M1/2) plane in the MSuGra model.
The solid black lines are contours
of constant BR(* Bs → μμ *), the dotted green lines are contours of constant
deviations of the muon (g-2) (in units of E-10) relative to SM expectations
and the dash-dot red lines are contours of constant (lowest-lying) higgs
mass in this model (in units of GeV). The shaded red-regions are
excluded.

A second interesting class of models that predicts enhanced rates
of * Bs → μμ * decay are SO(10) symmetry breaking models.
This plot from
(hep-ph/0304101) shows BR(Bs->&mu&mu)
in the (&mu,M1/2) plane. Dashed blue lines are are contours
of constant BR(* Bs → μμ *), dashed black lines are are contours of constant higgs
mass, green areas are regions of parameter space consistent with the
observed relic density of dark matter and pink ares are excluded. This model with the
choice of parameters shown in the plot is disfavored. A listing of relevant theory
papers is below.

BR(

BR(

- Figure: Central-Central(CMU-CMU) muon candidates invariant mass distribution
- Figure: Central-Forward(CMU-CMX) muon candidates invariant mass distribution
- Figure: Central-Central muon
*B &rarr J/&Psi K*invariant mass distribution - Figure: Central-Forward muon
*B &rarr J/&Psi K*invariant mass distribution - Figure: Pythia MC
*B &rarr J/&Psi K*: &mu&mu*K*invariant mass distribution - Figure:
*J/&Psi &rarr &mu&mu*, from*B &rarr J/&Psi K*: &mu&mu invariant mass distribution - Figure: Pythia MC
*J/&Psi &rarr &mu&mu*, from*B &rarr J/&Psi K*: &mu&mu invariant mass distribution - Figure: Pythia MC
*B*: &mu&mu invariant mass distribution_{s}&rarr &mu&mu - Figure: Transvers momentum, P
_{T}*B*distribution - Figure: Shape comparison between Pythia MC Signal and Background for discriminating variables
- Figure: Central-Central muon correlation plots for background
- Figure: Central-Forward muon correlation plots for background
- Figure: Central-Central muon likelihood PDFs
- Figure: Central-Forward muon likelihood PDFs
- Figure: Central-Central muon background likelihood distribution and comparison to Toy MC simulation
- Figure: Central-Forward muon background likelihood distribution and comparison to Toy MC simulation
- Figure: Central-Central muon
*B &rarr J/&Psi K*Shape comparison between Phythia MC and data Signal for discriminating variables - Figure: Central-Central muon
*B &rarr J/&Psi K*Shape comparison between Phythia MC and data Signal for discriminating variables - Figure: Likelihood distribution comparison between Pythia MC Signal and background
- Figure: Central-Central muon invariant mass distribution of events passing all cuts
- Figure: Central-Forward muon invariant mass distribution of events passing all cuts
- Figure: Central-Central muon likelihood distribution of events passing all cuts
- Figure: Central-Forward muon likelihood distribution of events passing all cuts
- Figure: Central-Central muon invariant mass vs. likelihood distribution of events passing all cuts
- Figure: Central-Forward muon invariant mass vs. likelihood distribution of events passing all cuts
- Web page : Di-muon trigger plots

A full description of the analysis is in cdfnote 7463

- geometric and kinematic acceptance: cdf-6204
- trigger efficiencies: cdf-7314
- muon efficiencies: cdf-6347, cdf-6612
- muon chi2: cdf-6114, cdf-6835
- tracking efficiencies: cdf-6318, cdf-6394
- muon fake-rates for pions and kaons in D* data sample: cdf-6273

The pre-blessing talk and
blessing talk at the *B* Physics meeting also offers a summary
of the analysis.

Combination CDF and D0: | BR( B) < 1.5x10_{s} → μμ ^{-7} @95% CL |
(hep-ex/0508058) |

D0 Run 2: | BR( B) < 3.7x10_{s} → μμ ^{-7} @95% CL |
(D0-Note 4733-Conf, Preliminary) |

D0 Run 2: | BR( B) < 5.0x10_{s} → μμ ^{-7} @95% CL |
(hep-ex/0410039, Phys. Rev. Letters 94, 071802 (2005)) |

CDF Run 2: | BR( B) < 7.5x10_{s} → μμ ^{-7} @95% CL |
(hep-ex/0403032 , Phys. Rev. Letters 93, 032001 2004) |

BaBar: | BR( B) < 8.3x10_{d} → μμ ^{-8} @90% CL |
(hep-ex/0408096) |

CDF Run 2: | BR( B) < 1.5x10_{d} → μμ ^{-7} @90% CL |
(hep-ex/0403032 , Phys. Rev. Letters 93, 032001 2004) |

Belle: | BR( B) < 1.6x10_{s} → μμ ^{-7} @90% CL |
(hep-ex/0309069 , Phys. Rev. D 68, 111101 (R) (2003) ) |

Measurement of the Negative Muon Anomalous Magnetic Moment to 0.7 ppm hep-ex/0401008, Phys.Rev.Lett. 92 (2004)

Web page for previous analysis

- hep-ph/0108037 Correlation of Bs -> mu+mu- and (g-2)mu in Minimal Supergravity
- hep-ph/0207026 Trilepton Events and Bs -> mu+mu- : No-lose for mSUGRA at the Tevatron?
- hep-ph/0203069 Detection of Bs->mu mu at the Tevatron Run II and Constraints on the SUSY Parameter Space
- hep-ph/0304303 Updated Constraints on the Minimal Supergravity Model
- hep-ph/0310042 Bs -> mumu as a Probe of Tan(beta) at the Tevatron
- hep-ph/0304101 Dark Matter And Bs to mu+mu- With Minimal SO(10) Soft SUSY Breaking
- hep-ph/0507233 Dark Matter And Bs to mu+mu- With Minimal SO(10) Soft SUSY Breaking II
- hep-ph/0302155 Yukawa Coupling Unification in Supersymmetric Models
- hep-ph/0501230 Non-Decoupling Effects of the Heavy T in the B{d,s} Mixing and Rare K and B Decays
- hep-ph/0407285 Bounding the MSSM Higgs sector from above with the Tevatron's Bs -> mu mu
- hep-ph/0504196 On the Interpretation of Bs -> mu mu in the CMSSM