Observation of J/ψϕ Structures Consistent with Exotic States from Amplitude Analysis of B^{+}→J/ψϕK^{+} Decays

The first full amplitude analysis of B^{+}→J/ψϕK^{+} with J/ψ→μ^{+}μ^{-}, ϕ→K^{+}K^{-} decays is performed with a data sample of 3  fb^{-1} of pp collision data collected at sqrt[s]=7 and 8 TeV with the LHCb detector. The data cannot be described by a model that contains only excited kaon states decaying into ϕK^{+}, and four J/ψϕ structures are observed, each with significance over 5 standard deviations. The quantum numbers of these structures are determined with significance of at least 4 standard deviations. The lightest has mass consistent with, but width much larger than, previous measurements of the claimed X(4140) state.

First Experimental Study of Photon Polarization in Radiative B_{s}^{0} Decays

The polarization of photons produced in radiative B_{s}^{0} decays is studied for the first time. The data are recorded by the LHCb experiment in pp collisions corresponding to an integrated luminosity of 3  fb^{-1} at center-of-mass energies of 7 and 8 TeV. A time-dependent analysis of the B_{s}^{0}→ϕγ decay rate is conducted to determine the parameter A^{Δ}, which is related to the ratio of right- over left-handed photon polarization amplitudes in b→sγ transitions. A value of A^{Δ}=-0.98_{-0.52}^{+0.46}_{-0.20}^{+0.23} is measured. This result is consistent with the standard model prediction within 2 standard deviations.

Search for Higgs-like bosons decaying into long-lived exotic particles

A search is presented for massive long-lived particles, in the 20-60 [Formula: see text] mass range with lifetimes between 5 and 100 [Formula: see text]. The dataset used corresponds to 0.62[Formula: see text] of proton-proton collision data collected by the LHCb detector at [Formula: see text]. The particles are assumed to be pair-produced by the decay of a Higgs-like boson with mass between 80 and 140 [Formula: see text]. No excess above the background expectation is observed and limits are set on the production cross-section as a function of the long-lived particle mass and lifetime and of the Higgs-like boson mass.

Search for Structure in the B_{s}^{0}π^{±} Invariant Mass Spectrum

The B_{s}^{0}π^{±} invariant mass distribution is investigated in order to search for possible exotic meson states. The analysis is based on a data sample recorded with the LHCb detector corresponding to 3  fb^{-1} of pp collision data at sqrt[s]=7 and 8 TeV. No significant excess is found, and upper limits are set on the production rate of the claimed X(5568) state within the LHCb acceptance. Upper limits are also set as a function of the mass and width of a possible exotic meson decaying to the B_{s}^{0}π^{±} final state. The same limits also apply to a possible exotic meson decaying through the chain B_{s}^{*0}π^{±}, B_{s}^{*0}→B_{s}^{0}γ where the photon is excluded from the reconstructed decays.