We present a search for anomalous semileptonic decays of heavy flavor hadrons produced in association with a $W$ boson in proton-antiproton collisions at $\sqrt{s}=1.96\mathrm{TeV}$. We use $162{\mathrm{pb}}^{-1}$ of data collected with the CDF II detector at the Fermilab Tevatron Collider. We select events with one $W$ boson and at least one jet with an identified secondary vertex. In the jets with a secondary vertex we look for a semileptonic decay to a muon. We compare the number of jets with both a secondary vertex and a semileptonic decay and the kinematic properties of these jets, with the standard model expectation of $W$ plus heavy flavor production and decay. No discrepancy is seen between the observation and the expectation, and we set limits on the production cross section of a $B$-like hadron with an anomalously high semileptonic branching ratio.

• Received 23 December 2005

DOI:https://doi.org/10.1103/PhysRevD.73.051101