Rare decays of heavy flavor at the Tevatron

TL;DR

This paper reviews recent experimental results on rare charm and bottom meson decays involving muons at the Tevatron, including improved limits and first observations with high significance.

Contribution

It reports the first direct observation of certain rare decays and provides improved upper limits on branching ratios of multiple rare meson decay modes.

Findings

First direct observation of D_s^+ → φ π^+ → μ^+ μ^- π^+ with >7σ significance.

Evidence for D^+ → φ π^+ → μ^+ μ^- π^+ with 3.1σ significance.

Improved upper limits on several rare decay branching ratios.

Abstract

In this report I review recent results in the field of rare decays at the Tevatron CDF II and D0 experiments. The presentation is focused on rare decays of charm and bottom mesons with two muons in the final state. This includes improvements over the previously available limits on the following branching ratios: $B(D^+ \to \pi^+ \mu^+ \mu^-)< 4.7 \times 10^{-6}$, B(B_s^0 \to \phi \mu^+ \mu^-)< 3.2\times 10^{-6}$, $B(B_s^0 \to \mu^+ \mu^-)< 1 \times 10^{-7}$, and $B(B_d^0)< 3 \times 10{-8}$ all at the 90% confidence level. Also reported are the first direct observation of $D_s^+ \to \phi \pi^+ \to \mu^+ \mu^- \pi^+$ with a significance above background of over 7 standard deviations and evidence of $D^+ \to \phi \pi^+ \to \mu^+ \mu^- \pi^+$ with a significance of 3.1 and $B(D^+ \to \phi \pi^+ \to \mu^+ \mu^- \pi^+)=(1.75 \pm0.7 \pm0.5) \times 10^{-6}$.