The latest results from studies of $b$ hadron decays to open charm final states at the LHCb experiment are presented. The results include measurements of $CP$ violation and the properties of $b$ baryons.
The X(3872) and Y(3940) properties and decay modes from Belle are reviewed and the results on a search for the decay $B^+ra h_c K^+$, $h_cra eta_c gamma$ at Belle are presented.
This article is a short and non-exhaustive summary of the prospects to find New Physics with LHCb as was presented at the HCP conference at Toronto on August 26th 2010.
While the LHC did not observe direct evidence for physics beyond the standard model, indirect hints for new physics were uncovered in the flavour sector in the decays $Bto K^*mu^+mu^-$, $Bto Kmu^+mu^-/Bto Ke^+e^-$, $B_stophimu^+mu^-$, $Bto D^{(*)}tau u$ and $htotau^pmmu^mp$. Each observable deviates from the SM predictions at the $2-3,sigma$ level only, but combining all $bto smu^+mu^-$ data via a global fit, one finds $4-5,sigma$ difference for NP compared to the SM and combining $Bto D^{*}tau u$ with $Bto Dtau u$ one obtains $3.9,sigma$. While $Bto D^{(*)}tau u$ and $htotaumu$ can be naturally explained by an extended Higgs sector, the $bto smu^+mu^-$ anomalies point at a $Z$ gauge boson. However, it is also possible to explain $Bto D^{(*)}tau u$ and $bto smu^+mu^-$ simultaneously with leptoquarks while their effect in $htotau^pmmu^mp$ is far too small to account for current data. Combining a 2HDM with a gauged $L_mu-L_tau$ symmetry allows for explaining the $bto smu^+mu^-$ anomalies in combination with $htotau^pmmu^mp$, predicting interesting correlations with $tauto3mu$. In the light of these deviations from the SM we also discuss the possibilities of observing lepton flavour violating $B$ decays (e.g. $Bto K^{(*)}tau^pmmu^mp$ and $B_stotau^pmmu^mp$).
We report the observation of a new $D_{sJ}$ meson produced in $B^{+} to bar{D}^{0} D_{sJ} to bar{D}^{0} D^{0} K^{+}$. This state has a mass of $M=2708 pm 9 ^{+11}_{-10} rm{MeV}/{it c}^{2}$, a width $Gamma = 108 pm 23 ^{+36}_{-31} ~rm{MeV}/ {it c}^{2}$ and a $1^{-}$ spin-parity. The results are based on an analysis of 449 million $Bbar{B}$ events collected at the $Upsilon(4S)$ resonance with the Belle detector at the KEKB asymmetric-energy $e^{+} e^{-}$ collider.
The unexpected absence of unambiguous signals of New Physics at the TeV scale at the Large Hadron Collider puts today flavour physics at the forefront. In particular rare decays of b-hadrons represent a unique probe to challenge the Standard Model paradigm and test models of New Physics at a scale much higher than that accessible by direct searches. This article reviews the status of the field.