Determination of the sign of the decay width difference in the B(s)(0) system.

The interference between the K+ K- S-wave and P-wave amplitudes in B(s)(0) → J/ψK+ K- decays with the K+ K- pairs in the region around the ϕ(1020) resonance is used to determine the variation of the difference of the strong phase between these amplitudes as a function of K+ K- invariant mass. Combined with the results from our CP asymmetry measurement in B(s)(0) → J/ψϕ decays, we conclude that the B(s)(0) mass eigenstate that is almost CP = +1 is lighter and decays faster than the mass eigenstate that is almost CP = -1. This determines the sign of the decay width difference ΔΓ(s) ≡ Γ(L) - Γ(H) to be positive.

Differential branching fraction and angular analysis of the decay B0 → K*0 μ+ μ-.

The angular distributions and the partial branching fraction of the decay B0 → K*0 μ+ μ- are studied by using an integrated luminosity of 0.37  fb(-1) of data collected with the LHCb detector. The forward-backward asymmetry of the muons, A(FB), the fraction of longitudinal polarization, F(L), and the partial branching fraction dB/dq2 are determined as a function of the dimuon invariant mass.

First observation of the decays B(0) → D(+)K(-)π(+)π(-) and B(-) → D(0)K(-)π(+)π(-).

First observations of the Cabibbo-suppressed decays B(0) → D(+)K(-)π(+)π(-) and B(-) → D(0)K(-)π(+)π(-) are reported using 35 pb(-1) of data collected with the LHCb detector. Their branching fractions are measured with respect to the corresponding Cabibbo-favored decays, from which we obtain B(B(0) → D(+)K(-)π(+)π(-))/B(B(0) → D(+)π(-)π(+)π(-))=(5.9±1.

Observation of B(s)(0) → J/ψf(2)'(1525) in J/ψK+ K- final states.

The decay B(s)(0) → J/ψK+ K- is investigated using 0.16  fb(-1) of data collected with the LHCb detector using 7 TeV pp collisions. Although the J/ψϕ channel is well known, final states at higher K+ K- masses have not previously been studied.