Study of charmonium production in $${b} $$ b -hadron decays and first evidence for the decay $${{{B}} ^0_{{s}}} \!\rightarrow \phi \phi \phi $$ B s 0 → ϕ ϕ ϕ

Abstract

Abstract Using decays to $$\phi $$ ϕ -meson pairs, the inclusive production of charmonium states in $${b} $$ b -hadron decays is studied with pp collision data corresponding to an integrated luminosity of $$3.0 {\,\mathrm{fb}}^{-1} $$ 3.0 fb - 1 , collected by the LHCb experiment at centre-of-mass energies of 7 and 8 TeV. Denoting by $${\mathcal {B}} _C \equiv {\mathcal {B}} ( {{b}} \!\rightarrow C X ) \times {\mathcal {B}} ( C\!\rightarrow \phi \phi )$$ B C ≡ B ( b → C X ) × B ( C → ϕ ϕ ) the inclusive branching fraction of a $${{b}} $$ b hadron to a charmonium state C that decays into a pair of $$\phi $$ ϕ mesons, ratios $$R^{C_1}_{C_2}\equiv {\mathcal {B}} _{C_1} / {\mathcal {B}} _{C_2}$$ R C 2 C 1 ≡ B C 1 / B C 2 are determined as $$R^{{\upchi _{{{c}} 0}}}_{{\eta _{{c}}} (1S)} = 0.147 \pm 0.023 \pm 0.011$$ R η c ( 1 S ) χ c 0 = 0.147 ± 0.023 ± 0.011 , $$R^{{\upchi _{{{c}} 1}}}_{{\eta _{{c}}} (1S)} = 0.073 \pm 0.016 \pm 0.006$$ R η c ( 1 S ) χ c 1 = 0.073 ± 0.016 ± 0.006 , $$R^{{\upchi _{{{c}} 2}}}_{{\eta _{{c}}} (1S)} = 0.081 \pm 0.013 \pm 0.005$$ R η c ( 1 S ) χ c 2 = 0.081 ± 0.013 ± 0.005 , $$R^{{\upchi _{{{c}} 1}}}_{{\upchi _{{{c}} 0}}} = 0.50 \pm 0.11 \pm 0.01$$ R χ c 0 χ c 1 = 0.50 ± 0.11 ± 0.01 , $$R^{{\upchi _{{{c}} 2}}}_{{\upchi _{{{c}} 0}}} = 0.56 \pm 0.10 \pm 0.01$$ R χ c 0 χ c 2 = 0.56 ± 0.10 ± 0.01 and $$R^{{\eta _{{c}}} (2S)}_{{\eta _{{c}}} (1S)} = 0.040 \pm 0.011 \pm 0.004$$ 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 $${\upchi _{{{c}} 2}} (2P)$$ χ c 2 ( 2 P ) states are obtained as $$R^{X(3872)}_{{\upchi _{{{c}} 1}}} < 0.34$$ R χ c 1 X ( 3872 ) < 0.34 , $$R^{X(3915)}_{{\upchi _{{{c}} 0}}} < 0.12$$ R χ c 0 X ( 3915 ) < 0.12 and $$R^{{\upchi _{{{c}} 2}} (2P)}_{{\upchi _{{{c}} 2}}} < 0.16$$ R χ c 2 χ c 2 ( 2 P ) < 0.16 . Differential cross-sections as a function of transverse momentum are measured for the $${\eta _{{c}}} (1S)$$ η c ( 1 S ) and $$\chi _c$$ χ c states. The branching fraction of the decay $${{{B}} ^0_{{s}}} \!\rightarrow \phi \phi \phi $$ B s 0 → ϕ ϕ ϕ is measured for the first time, $${\mathcal {B}} ( {{{B}} ^0_{{s}}} \!\rightarrow \phi \phi \phi ) = (2.15 \pm 0.54 \pm 0.28 \pm 0.21_{{\mathcal {B}}}) \times 10^{-6}$$ 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 $${{{B}} ^0_{{s}}} \!\rightarrow \phi \phi $$ B s 0 → ϕ ϕ , which is used for normalization. No evidence for intermediate resonances is seen. A preferentially transverse $$\phi $$ ϕ polarization is observed. The measurements allow the determination of the ratio of the branching fractions for the $${\eta _{{c}}} (1S)$$ η c ( 1 S ) decays to $$\phi \phi $$ ϕ ϕ and $${{p}} {\overline{{{p}}}} $$ p p ¯ as $${\mathcal {B}} ( {\eta _{{c}}} (1S)\!\rightarrow \phi \phi )/{\mathcal {B}} ( {\eta _{{c}}} (1S)\!\rightarrow {{p}} {\overline{{{p}}}} ) = 1.79 \pm 0.14\pm 0.32$$ B ( η c ( 1 S ) → ϕ ϕ ) / B ( η c ( 1 S ) → p p ¯ ) = 1.79 ± 0.14 ± 0.32 .