Vorabdrucke

We report a measurement of the $\pi^-$ photoproduction beam asymmetry for the reaction $\vec{\gamma} p \rightarrow \pi^- \Delta^{++}$ using data from the GlueX experiment in the photon beam energy range 8.2--8.8 GeV. The asymmetry $\Sigma$ is measured as a function of four-momentum transfer $t$ to the $\Delta^{++}$ and compared to phenomenological models. [...]

Based on 586 $\rm{pb^{-1}}$ of $e^+e^-$ annihilation data collected at a center-of-mass energy of $\sqrt{s}=4.6~\rm{GeV}$ with the BESIII detector at the BEPCII collider, the absolute branching fraction of $\Lambda_c^+ \to p K^0_{\mathrm{S}}\eta$ decays is measured for the first time to be $\mathcal{B}(\Lambda_c^+ \to p K^0_{\mathrm{S}}\eta) = (0.414 \pm 0.084 \pm 0.028)\%$, where the first uncertainty is statistical and the second is systematic. The result is compatible with a previous CLEO result on the relative branching fraction $\frac{\mathcal{B}(\Lambda_c^+ \to p K^0_{\mathrm{S}}\eta)}{\mathcal{B}(\Lambda_c^+ \to p K^-\pi^+)}$, and consistent with theoretical predictions of SU(3) flavor symmetry..

The Born cross sections for the process $e^+e^- \to \eta^\prime \pi^{+}\pi^{-}$ at different center-of-mass energies between $2.00$ and $3.08$~GeV are reported with improved precision from an analysis of data samples collected with the BESIII detector operating at the BEPCII storage ring. An obvious structure is observed in the Born cross section line shape. [...]

Using a sample of $1.31\times10^{9} ~J/\psi$ events collected with the BESIII detector, we perform a study of $J/\psi\to\gamma\eta\eta\eta^{\prime}$ to search for the $X(2370)$ and $\eta_{c}$ in the $\eta\eta\eta^{\prime}$ invariant mass distribution. No significant signal for the $X(2370)$ is observed, and we set an upper limit for the product branching fraction of ${\cal B}(J/\psi\to\gamma X(2370)\cdot{\cal B}(X(2370)\to\eta\eta\eta^{\prime}) < 9.2\times10^{-6}$ at the 90% confidence level. [...]

Using $(1310.6 \pm 7.0) \times 10^{6}~J/\psi$ events acquired with the BESIII detector at the BEPCII storage rings, the decay $\eta^\prime\rightarrow\pi^+\pi^-\mu^+\mu^-$ is observed for the first time with a significance of 8$\sigma$ via the process $J/\psi\rightarrow\gamma\eta'$. We measure the branching fraction of $\eta^\prime\rightarrow\pi^+\pi^-\mu^+\mu^-$ to be $\mathcal{B}(\eta^\prime\rightarrow\pi^+\pi^-\mu^+\mu^-)$=(1.97$\pm$0.33(stat.)$\pm$0.18(syst.))$\times10^{-5}$, where the first and second uncertainties are statistical and systematic, respectively..

Using a data sample of $(1310.6 \pm 7.0) \times 10^{6}$ $J/\psi$ events taken with the BESIII detector at the center-of-mass energy of 3.097 GeV, we search for the first time for the lepton number violating decay $\Sigma^{-} \to p e^{-} e^{-}$ and the rare inclusive decay $\Sigma^{-} \to \Sigma^{+} X$, where $X$ denotes any possible particle combination. The $\Sigma^-$ candidates are tagged in $J/\psi \to \bar{\Sigma}(1385)^+\Sigma^-$ decays. [...]

We search for the process $e^{+}e^{-}\rightarrow \pi ^{+}\pi ^{-} \chi_{cJ}$ ($J=0,1,2$) and for a charged charmonium-like state in the $\pi ^{\pm} \chi_{cJ}$ subsystem. The search uses data sets collected with the BESIII detector at the BEPCII storage ring at center-of-mass energies between 4.18 GeV and 4.60 GeV. [...]

Using data collected with the BESIII detector operating at the Beijing Electron Positron Collider, we search for the process $e^+e^-\rightarrow \eta_c\eta \pi^+\pi^-$. The search is performed using five large data sets recorded at center-of-mass energies of 4.23, 4.26, 4.36, 4.42, and 4.60 GeV. [...]

We report an amplitude analysis and branching fraction measurement of $D_{s}^{+} \rightarrow K^{+}K^{-}\pi^{+}$ decay using a data sample of 3.19 $\rm fb^{-1}$ recorded with BESIII detector at a center-of-mass energy of 4.178 GeV. We perform a model-independent partial wave analysis in the low $K^{+}K^{-}$ mass region to determine the $K^{+}K^{-}$ S-wave lineshape, followed by an amplitude analysis of our very pure high-statistics sample. [...]

The rare decay $\eta' \to \pi^+ \pi^- e^+ e^-$ is studied using a sample of $1.3 \times 10^9$ $J/\psi$ events collected with the BESIII detector at BEPCII in 2009 and 2012. The branching fraction is measured with improved precision to be $\left( 2.42\pm0.05_{stat.}\pm0.08_{syst.} \right) \times 10^{-3}$. [...]