Searches for rare B-s(0) and B-0 decays into four muons

Searches for rare B-s(0) and B-0 decays into four muons are performed using proton-proton collision data recorded by the LHCb experiment, corresponding to an integrated luminosity of 9 fb(-1). Direct decays and decays via light scalar and J/psi resonances are considered. No evidence for the six decays searched for is found and upper limits at the 95% confidence level on their branching fractions ranging between 1.8 x 10(-10) and 2.6 x 10(-9) are set

Searches for rare Bs0 and B 0 decays into four muons

Searches for rare Bs0 and B0 decays into four muons are performed using proton-proton collision data recorded by the LHCb experiment, corresponding to an integrated luminosity of 9 fb−1. Direct decays and decays via light scalar and J/ψ resonances are considered. No evidence for the six decays searched for is found and upper limits at the 95% confidence level on their branching fractions ranging between 1.8 × 10−10 and 2.6 × 10−9 are set. [Figure not available: see fulltext.

Observation of a New Excited Ds+ Meson in B0 → D− D+ K+ π− Decays

Using pp collision data corresponding to an integrated luminosity of 5.4 fb^−1 collected with the LHCb detector at a center-of-mass energy of 13 TeV, the B0 → D− D+ K+ π− decay is studied. A new excited Ds+ meson is observed decaying into the D+ K+ π− final state with large statistical significance. The pole mass and width, and the spin parity of the new state are measured with an amplitude analysis to be m_R = 2591 ± 6 ± 7 MeV, Γ_R = 89 ± 16 ± 12 MeV, and J^P = 0−, where the first uncertainty is statistical and the second systematic. Fit fractions for all components in the amplitude analysis are also reported. The new resonance, denoted as Ds0(2590)+, is a strong candidate to be the Ds(2^1S_0)+ state, the radial excitation of the pseudoscalar ground-state Ds+ meson

Observation of the Λb0→Λc+K+K−π− decay

The Λb0→Λc+K+K−π− decay is observed for the first time using a data sample of proton-proton collisions at centre-of-mass energies of s=7 and 8TeV collected by the LHCb detector, corresponding to an integrated luminosity of 3fb−1. The ratio of branching fractions between the Λb0→Λc+K+K−π− and the Λb0→Λc+Ds− decays is measured to be [Formula presented] where the first uncertainty is statistical, the second systematic and the third is due to the knowledge of the Ds−→K+K−π− branching fraction. No structure on the invariant mass distribution of the Λc+K+ system is found, consistent with no open-charm pentaquark signature. © 2021 The Author(s