No Arabic abstract
Using a sample of $1.31$ billion $J/psi$ events accumulated with the BESIII detector at the BEPCII collider, we report the observation of the decay $J/psi rightarrow phipi^{0}$, which is the first evidence for a doubly Okubo-Zweig-Iizuka suppressed electromagnetic $J/psi$ decay. A clear structure is observed in the $K^{+} K^{-}$ mass spectrum around 1.02 GeV/$c^2$, which can be attributed to interference between $J/psi rightarrow phipi^{0}$ and $J/psi rightarrow K^{+}K^{-}pi^{0}$ decays. Due to this interference, two possible solutions are found. The corresponding measured values of the branching fraction of $J/psi to phipi^{0}$ are $[2.94 pm 0.16text{(stat.)} pm 0.16text{(syst.)}] times 10^{-6}$ and $[1.24 pm 0.33text{(stat.)} pm 0.30text{(syst.)}] times 10^{-7}$.
The $B_s^0 rightarrow J/psi phi phi$ decay is observed in $pp$ collision data corresponding to an integrated luminosity of 3 fb$^{-1}$ recorded by the LHCb detector at centre-of-mass energies of 7 TeV and 8 TeV. This is the first observation of this decay channel, with a statistical significance of 15 standard deviations. The mass of the $B_s^0$ meson is measured to be $5367.08,pm ,0.38,pm, 0.15$ MeV/c$^2$. The branching fraction ratio $mathcal{B}(B_s^0 rightarrow J/psi phi phi)/mathcal{B}(B_s^0 rightarrow J/psi phi)$ is measured to be $0.0115,pm, 0.0012, ^{+0.0005}_{-0.0009}$. In both cases, the first uncertainty is statistical and the second is systematic. No evidence for non-resonant $B_s^0 rightarrow J/psi phi K^+ K^-$ or $B_s^0 rightarrow J/psi K^+ K^- K^+ K^-$ decays is found.
A search for the rare decay $B^0 rightarrow J/psi phi$ is performed using $pp$ collision data collected with the LHCb detector at centre-of-mass energies of 7, 8 and 13 TeV, corresponding to an integrated luminosity of 9 ${rm fb}^{-1}$. No significan
The decay $B_crightarrow J/psi K^+ K^- pi^+$ is observed for the first time, using proton-proton collisions collected with the LHCb detector corresponding to an integrated luminosity of 3fb$^{-1}$. A signal yield of $78pm14$ decays is reported with a significance of 6.2 standard deviations. The ratio of the branching fraction of $B_c rightarrow J/psi K^+ K^- pi^+$ decays to that of $B_c rightarrow J/psi pi^+$ decays is measured to be $0.53pm 0.10pm0.05$, where the first uncertainty is statistical and the second is systematic.
Decays of the form $B^{0}_{(s)}rightarrow J/psi K_{{rm S}}^{0} h^+ h^{left(primeright) -}$ ($h^{(prime)} = K, pi$) are searched for in proton-proton collision data corresponding to an integrated luminosity of $1.0 , {rm fb}^{-1}$ recorded with the LHCb detector. The first observation of the $B^{0}_{s}rightarrow J/psi K_{{rm S}}^{0} K^{pm} pi^{mp}$ decay is reported, with significance in excess of 10 standard deviations. The $B^{0}rightarrow J/psi K_{{rm S}}^{0} K^{+} K^{-}$ decay is also observed for the first time. The branching fraction of $B^{0}rightarrow J/psi K_{{rm S}}^{0} pi^{+} pi^{-}$ is determined, to significantly better precision than previous measurements, using $B^0 rightarrow J/psi K_{{rm S}}^{0}$ as a normalisation channel. Branching fractions and upper limits of the other $B^{0}_{(s)}rightarrow J/psi K_{{rm S}}^{0} h^+ h^{left(primeright) -}$ modes are determined relative to that of the $B^{0}rightarrow J/psi K_{{rm S}}^{0} pi^{+} pi^{-}$ decay.
A measurement of the relative branching fraction of $B_{s}^{0} rightarrow J/ps i f_{0}(980), f_{0}(980) rightarrow pi^{+}pi^{-}$ to $B_{s}^{0} rightarrow J/psi phi, p hi rightarrow K^{+}K^{-}$ is presented. The decay mode $B_{s}^{0} rightarrow J/psi f_{0}(980)$ is an interesting mode since it is a CP-odd eigenstate which could be used in CP-violating studies. Using approximat ely 8 $rm{fb}^{-1}$ of data recorded with the D0 detector at the Fermilab Tevatron Collider, a relative branching fraction of 0.210 $pm$ 0.032thinspace(stat) $pm$ 0.036thi nspace(syst) is found.