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A bstract An amplitude analysis of the decay Λ b 0  →  D 0 pπ − is performed in the part of the phase space containing resonances in the D 0 p channel. The study is based on a data sample corresponding to an integrated luminosity of 3.0 fb −1 of pp collisions recorded by the LHCb experiment. The spectrum of excited Λ c + states that decay into D 0 p is studied. The masses, widths and quantum numbers of the Λ c (2880) + and Λ c (2940) + resonances are measured. The constraints on the spin and parity for the Λ c (2940) + state are obtained for the first time. A near-threshold enhancement in the D 0 p amplitude is investigated and found to be consistent with a new resonance, denoted the Λ c (2860) + , of spin 3 / 2 and positive parity.

A bstract A search for CP and P violation using triple-product asymmetries is performed with Λ b 0  →  pK − π + π − , Λ b 0  →  pK − K + K − and Ξ b 0  →  pK − K − π + decays. The data sample corresponds to integrated luminosities of 1.0 fb −1 and 2.0 fb −1 , recorded with the LHCb detector at centre-of-mass energies of 7 TeV and 8 TeV, respectively. The CP - and P - violating asymmetries are measured both integrating over all phase space and in specific phase-space regions. No significant deviation from CP or P symmetry is found. The first observation of Λ b 0  →  pK − χ c0 (1 P )(→ π + π − ,  K + K − ) decay is also reported.

A bstract A search for charmless four-body decays of Λ b 0 and Ξ b 0 baryons with a proton and three charged mesons (either kaons or pions) in the final state is performed. The data sample used was recorded in 2011 and 2012 with the LHCb experiment and corresponds to an integrated luminosity of 3 fb −1 . Six decay modes are observed, among which Λ b 0  →  pK − π + π − , Λ b 0  →  pK − K + K − , Ξ b 0  →  pK − π + π − and Ξ b 0  →  pK − π + K − are established for the first time. Their branching fractions (including the ratio of hadronisation fractions in the case of the Ξ b 0 baryon) are determined relative to the Λ b 0  →  Λ c + π − decay.

Using decays to ϕ -meson pairs, the inclusive production of charmonium states in b -hadron decays is studied with pp collision data corresponding to an integrated luminosity of 3.0 fb - 1 , collected by the LHCb experiment at centre-of-mass energies of 7 and 8 TeV. Denoting by B C ≡ B ( b → C X ) × B ( C → ϕ ϕ ) the inclusive branching fraction of a b hadron to a charmonium state C that decays into a pair of ϕ mesons, ratios R C 2 C 1 ≡ B C 1 / B C 2 are determined as R η c ( 1 S ) χ c 0 = 0.147 ± 0.023 ± 0.011 , R η c ( 1 S ) χ c 1 = 0.073 ± 0.016 ± 0.006 , R η c ( 1 S ) χ c 2 = 0.081 ± 0.013 ± 0.005 , R χ c 0 χ c 1 = 0.50 ± 0.11 ± 0.01 , R χ c 0 χ c 2 = 0.56 ± 0.10 ± 0.01 and R η c ( 1 S ) η c ( 2 S ) = 0.040 ± 0.011 ± 0.004 . Here and below the first uncertainties are statistical and the second systematic. Upper limits at 90% confidence level for the inclusive production of X (3872), X (3915) and χ c 2 ( 2 P ) states are obtained as R χ c 1 X ( 3872 ) < 0.34 , R χ c 0 X ( 3915 ) < 0.12 and R χ c 2 χ c 2 ( 2 P ) < 0.16 . Differential cross-sections as a function of transverse momentum are measured for the η c ( 1 S ) and χ c states. The branching fraction of the decay B s 0 → ϕ ϕ ϕ is measured for the first time, B ( B s 0 → ϕ ϕ ϕ ) = ( 2.15 ± 0.54 ± 0.28 ± 0 . 21 B ) × 10 - 6 . Here the third uncertainty is due to the branching fraction of the decay B s 0 → ϕ ϕ , which is used for normalization. No evidence for intermediate resonances is seen. A preferentially transverse ϕ polarization is observed. The measurements allow the determination of the ratio of the branching fractions for the η c ( 1 S ) decays to ϕ ϕ and p p ¯ as B ( η c ( 1 S ) → ϕ ϕ ) / B ( η c ( 1 S ) → p p ¯ ) = 1.79 ± 0.14 ± 0.32 .

A precision measurement of the$$ {B}_c^{+} $$B c + meson mass is performed using proton- proton collision data collected with the LHCb experiment at centre-of-mass energies of 7 , 8 and 13 TeV, corresponding to a total integrated luminosity of 9 . 0 fb − 1 . The$$ {B}_c^{+} $$B c + mesons are reconstructed via the decays$$ {B}_c^{+} $$B c + → J/ψπ + ,$$ {B}_c^{+} $$B c + → J/ψπ + π − π + ,$$ {B}_c^{+}\\to J/\\psi p\\overline{p}{\\pi}^{+} $$B c + → J / ψp p ¯ π + ,$$ {B}_c^{+}\\to J/\\psi {D}_s^{+} $$B c + → J / ψ D s + ,$$ {B}_c^{+} $$B c + → J/ψ D 0 K + and$$ {B}_c^{+}\\to {B}_s^0{\\pi}^{+} $$B c + → B s 0 π + . Combining the results of the individual decay channels, the$$ {B}_c^{+} $$B c + mass is measured to be 6274 . 47 ± 0 . 27 (stat) ± 0 . 17 (syst) MeV /c 2 . This is the most precise measurement of the$$ {B}_c^{+} $$B c + mass to date. The difference between the$$ {B}_c^{+} $$B c + and$$ {B}_s^0 $$B s 0 meson masses is measured to be 907 . 75 ± 0 . 37 (stat) ± 0 . 27 (syst) MeV /c .