Angular correlations in $B^+to X(3872) K^+$ decays, with $X(3872)to rho^0 J/psi$, $rho^0topi^+pi^-$ and $J/psi tomu^+mu^-$, are used to measure orbital angular momentum contributions and to determine the $J^{PC}$ value of the $X(3872)$ meson. The dat
a correspond to an integrated luminosity of 3.0 fb$^{-1}$ of proton-proton collisions collected with the LHCb detector. This determination, for the first time performed without assuming a value for the orbital angular momentum, confirms the quantum numbers to be $J^{PC}=1^{++}$. The $X(3872)$ is found to decay predominantly through S wave and an upper limit of $4%$ at $95%$ C.L. is set on the fraction of D wave.
The first measurement that relates semileptonic and hadronic decay rates of the $B_c^+$ meson is performed using proton-proton collision data corresponding to 1.0 fb$^{-1}$ of integrated luminosity collected with the LHCb detector. The measured value
of the ratio of branching fractions, ${cal B}(B_c^+ to J/psi pi^+)/{cal B}(B_c^+to J/psimu^+ u_mu)=0.0469 pm 0.0028 (stat.) pm 0.0046 (syst.)$, is at the lower end of available theoretical predictions.
Resonant structures in $B^0topsipi^-K^+$ decays are analyzed by performing a four-dimensional fit of the decay amplitude, using $pp$ collision data corresponding to $rm 3 fb^{-1}$ collected with the LHCb detector. The data cannot be described with $K
^+pi^-$ resonances alone, which is confirmed with a model-independent approach. A highly significant $Z(4430)^-topsipi^-$ component is required, thus confirming the existence of this state. The observed evolution of the $Z(4430)^-$ amplitude with the $psipi^-$ mass establishes the resonant nature of this particle. The mass and width measurements are substantially improved. The spin-parity is determined unambiguously to be $1^+$.
The decay Bc+ --> J/psi pi+pi-pi+ is observed for the first time, using 0.8 fb-1 of pp collisions at sqrt{s}=7 TeV collected by the LHCb experiment. The ratio of branching fractions BR(Bc+ --> J/psi pi+pi-pi+)/BR(B_c+ --> J/psi pi+) is measured to be
2.41+-0.30+-0.33, where the first uncertainty is statistical and the second systematic. The result is in agreement with theoretical predictions.
A search for the X(4140) state in B+ to J/psi phi K+ decays is performed with 0.37 fb-1 of pp collisions at sqrt(s)=7 TeV collected by the LHCb experiment. No evidence for this state is found, in 2.4 sigma disagreement with a measurement by CDF. An u
pper limit on its production rate is set, BR(B+ to X(4140) K+) BR(X(4140) to J/psi phi) / BR(B+ to J/psi phi K+) < 0.07 at 90% confidence level.
