No Arabic abstract
Using $2.25times10^{8}$ $J/psi$ events collected with the BESIII detector at the BEPCII storage rings, we observe for the first time the process $J/psirightarrow pbar{p}a_{0}(980)$, $a_{0}(980)rightarrow pi^{0}eta$ with a significance of $6.5sigma$ ($3.2sigma$ including systematic uncertainties). The product branching fraction of $J/psirightarrow pbar{p}a_{0}(980)rightarrow pbar{p}pi^{0}eta$ is measured to be $(6.8pm1.2pm1.3)times 10^{-5}$, where the first error is statistical and the second is systematic. This measurement provides information on the $a_{0}$ production near threshold coupling to $pbar{p}$ and improves the understanding of the dynamics of $J/psi$ decays to four body processes.
The decay $J/psi rightarrow omega p bar{p}$ has been studied, using $225.3times 10^{6}$ $J/psi$ events accumulated at BESIII. No significant enhancement near the $pbar{p}$ invariant-mass threshold (denoted as $X(pbar{p})$) is observed. The upper limit of the branching fraction $mathcal{B}(J/psi rightarrow omega X(pbar{p}) rightarrow omega p bar{p})$ is determined to be $3.9times10^{-6}$ at the 95% confidence level. The branching fraction of $J/psi rightarrow omega p bar{p}$ is measured to be $mathcal{B}(J/psi rightarrow omega p bar{p}) =(9.0 pm 0.2 (text{stat.})pm 0.9 (text{syst.})) times 10^{-4}$.
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.
Using a data sample of $1.31 times 10^{9}$ $J/psi$ events accumulated with the BESIII detector, the decay $J/psito pbar{p}phi$ is studied via two decay modes, $phito K^{0}_{S}K^{0}_{L}$ and $phito K^{+}K^{-}$. The branching fraction of $J/psito pbar{p}phi$ is measured to be $mathcal{B}(J/psito pbar{p}phi)=[5.23pm0.06(mbox{stat})pm0.33(mbox{syst})]times10^{-5}$, which agrees well with a previously published measurement, but with a significantly improved precision. No evident enhancement near the $pbar{p}$ mass threshold, denoted as $X(pbar{p})$, is observed, and the upper limit on the branching fraction of $J/psito X(pbar{p})phito pbar{p}phi$ is determined to be $mathcal{B}(J/psito X(pbar{p})phito pbar{p}phi)<2.1times10^{-7}$ at the 90% confidence level.
We present the first amplitude analysis of the decay $D^{+}_{s} rightarrow pi^{+}pi^{0}eta$. We use an $e^{+}e^{-}$ collision data sample corresponding to an integrated luminosity of 3.19~${mbox{,fb}^{-1}}$ collected with the BESIII detector at a center-of-mass energy of $4.178$ GeV. We observe for the first time the pure $W$-annihilation decays $D_{s}^{+} rightarrow a_{0}(980)^{+}pi^{0}$ and $D_{s}^{+} rightarrow a_{0}(980)^{0}pi^{+}$. We measure the absolute branching fractions $mathcal{B}(D_{s}^{+} rightarrow a_{0}(980)^{+(0)}pi^{0^(+)}, a_{0}(980)^{+(0)} to pi^{+(0)}eta) = (1.46pm0.15_{{rm stat.}}pm0.23_{{rm sys.}})$%, which is larger than the branching fractions of other measured pure $W$-annihilation decays by at least one order of magnitude. In addition, we measure the branching fraction of $D_{s}^{+} rightarrow pi^{+}pi^{0}eta$ with significantly improved precision.
Using a sample of 1.31 billion $J/psi$ events collected with the BESIII detector at the BEPCII collider, the decays $J/psi to phi pi^{+}pi^{-}pi^{0}$ and $J/psi to phi pi^{0}pi^{0}pi^{0}$ are investigated. The isospin violating decay $J/psi to phi pi^{0} f_{0}(980)$ with $f_{0}(980) to pipi$, is observed for the first time. The width of the $f_{0}(980)$ obtained from the dipion mass spectrum is found to be much smaller than the world average value. In the $pi^{0} f_{0}(980)$ mass spectrum, there is evidence of $f_1(1285)$ production. By studying the decay $J/psi to phieta$, the branching fractions of $eta to pi^{+}pi^{-}pi^{0}$ and $eta to pi^{0}pi^{0}pi^{0}$, as well as their ratio, are also measured.