We report on a search for the decay B+ -> D*+ K0_S and its charge conjugate with the CLEO detector at the Cornell Electron Storage Ring (CESR). No candidates are found in 9.10/fb of data. The background is estimated to be 0.29 +- 0.05 leading to an upper limit BF(B+ -> D*+ K0_S) = 9.5 x 10^{-5} (90% C.L.).
A search for the decay Bs -> D*-+ pi+- is presented using a data sample corresponding to an integrated luminosity of 1.0 fb-1 of pp collisions collected by LHCb. This decay is expected to be mediated by a W-exchange diagram, with little contribution
from rescattering processes, and therefore a measurement of the branching fraction will help to understand the mechanism behind related decays such as Bs -> pi+ pi- and Bs -> D Dbar. Systematic uncertainties are minimised by using B0 -> D*-+ pi+- as a normalisation channel. We find no evidence for a signal, and set an upper limit on the branching fraction of BR(Bs -> D*-+ pi+-) < 6.1 (7.8) x10^(-6) at 90% (95%) confidence level.
We report a search for CP-violating asymmetry in B0 -> D*+- D-+ decays. The analysis employs two methods of B0 reconstruction: full and partial. In the full reconstruction method all daughter particles of the B0 are required to be detected; the parti
al reconstruction technique requires a fully reconstructed D- and only a slow pion from the D*+ -> D0 pi_slow+ decay. From a fit to the distribution of the time interval corresponding to the distance between two B meson decay points we calculate the CP-violating parameters and find the significance of nonzero CP asymmetry to be 2.7 standard deviations.
We search for the rare decay $D^+to D^0 e^+ u_{e}$, using a data set with an integrated luminosity of 2.93 $rm fb^{-1}$ collected at $sqrt{s}=3.773$ GeV with the BESIII detector operating at the BEPCII storage rings. No signals are observed. We set t
he upper limit on the branching fraction for $D^+to D^0 e^+ u_e$ to be $1.0times 10^{-4}$ at the 90% confidence level.
We present the first search for the decay $D^+_{s}to omega e^{+} u$ to test the four-quark content of the $D^+_{s}$ and the $omega$-$phi$ mixing model for this decay. We use 586 $mathrm{pb}^{-1}$ of $e^{+}e^{-}$ collision data collected at a center-o
f-mass energy of 4170 MeV. We find no evidence of a signal, and set an upper limit on the branching fraction of $mathcal{B}(D^+_{s}toomega e^+ u)<$0.20% at the 90% confidence level.
We search for the rare radiative decay $D^0togammagamma$ using a data sample with an integrated luminosity of $832{rm fb^{-1}}$ recorded by the Belle detector at the KEKB $e^+e^-$ asymmetric-energy collider. We find no statistically significant signa
l and set an upper limit on the branching fraction of ${cal B}(D^0togammagamma)<8.5times10^{-7}$ at $90%$ confidence level. This is the most restrictive limit on the decay channel to date.