# Open Access

Latest additions:
 2019-01-0813:21 [GSI-2019-00059] Journal Article et al Measurement of $^{4}$He charge- and mass-changing cross sections on H, C, O, and Si targets in the energy range 70–220 MeV/u for radiation transport calculations in ion-beam therapy Physical review / C covering nuclear physics 99(1), 014603 (2019) [10.1103/PhysRevC.99.014603] OpenAccess: PDF; 2019-01-0714:38 [GSI-2019-00047] Journal Article et al Dalitz plot analysis of the decay $\omega \to \pi^+ \pi⁻ \pi^0$ Physical review / D D 98(11), 112007 (2018) [10.1103/PhysRevD.98.112007] OpenAccess: PDF; 2019-01-0411:36 [GSI-2019-00045] Journal Article et al Observation of $D^{0( + )} \to K_S^0 \pi^{0 ( + )} \eta^\prime$ and improved measurement of $D^0 → K^− \pi^+ \eta^\prime$ Physical review / D D 98(9), 092009 (2018) [10.1103/PhysRevD.98.092009] By analyzing $2.93\ \rm fb^{-1}$ of data taken at a center-of-mass energy of 3.773~GeV with the BESIII detector, we measure the branching fractions of the Cabibbo-favored hadronic decays $D^0\to K^-\pi^+\eta^\prime$, $D^0\to K^0_S\pi^0\eta^\prime$ and $D^+\to K^0_S\pi^+\eta^\prime$, which are determined to be $(6.43 \pm 0.15_{\rm stat.} \pm 0.31_{\rm syst.})\times 10^{-3}$, $(2.52 \pm 0.22_{\rm stat.} \pm 0.15_{\rm syst.})\times 10^{-3}$ and $(1.90 \pm 0.17_{\rm stat.} \pm 0.13_{\rm syst.})\times 10^{-3}$, respectively. The precision of the branching fraction of $D^0\to K^-\pi^+\eta^\prime$ is significantly improved, and the processes $D^0\to K^0_S\pi^0\eta^\prime$ and $D^+\to K^0_S\pi^+\eta^\prime$ are observed for the first time.. OpenAccess: PDF; 2019-01-0317:48 [GSI-2019-00036] Journal Article et al First measurement of $e^+ e^− → p K_S^0 \bar{n} K^− + c . c .$ above open charm threshold Physical review / D D 98(3), 032014 (2018) [10.1103/PhysRevD.98.032014] The process $e^+e^-\rightarrow pK^{0}_{S}\bar{n}K^{-} + c.c.$ and its intermediate processes are studied for the first time, using data samples collected with the BESIII detector at BEPCII at center-of-mass energies of 3.773, 4.008, 4.226, 4.258, 4.358, 4.416, and 4.600 GeV, with a total integrated luminosity of 7.4 fb$^{-1}$. The Born cross section of $e^+e^- \to p K^{0}_S\bar{n}K^- + c.c.$ is measured at each center-of-mass energy, but no significant resonant structure in the measured cross-section line shape between 3.773 and 4.600 GeV is observed. [...] OpenAccess: PDF; 2019-01-0317:41 [GSI-2019-00035] Journal Article et al Measurement of the Absolute Branching Fraction of the Inclusive Semileptonic $Λ_c^+$ Decay Physical review letters 121(25), 251801 (2018) [10.1103/PhysRevLett.121.251801] Using a data sample corresponding to an integrated luminosity of 567 pb$^{-1}$ collected at a center-of-mass energy of $\sqrt{s}=4.6$ GeV with the BESIII detector, we measure the absolute branching fraction of the inclusive semileptonic $\Lambda_c^+$ decay with a double-tag method. We obtain $\mathcal{B}(\Lambda_c^+ \rightarrow X e^+ \nu_e) = (3.95\pm0.34\pm0.09)\%$, where the first uncertainty is statistical and the second systematic. [...] OpenAccess: PDF; 2019-01-0317:38 [GSI-2019-00034] Journal Article et al Search for invisible decays of $ω$ and $ϕ$ with $J / ψ$ data at BESIII Physical review / D D 98(3), 032001 (2018) [10.1103/PhysRevD.98.032001] Using a data sample of $(1310.6 \pm 7.0)\times 10^6$ $J/\psi$ events collected with the BESIII detector operating at the BEPCII collider, we perform the first experimental search for invisible decays of a light vector meson ($V=\omega,\phi$) via $J/\psi \to V \eta$ decays. The decay of $\eta \to \pi^+\pi^-\pi^0$ is utilized to tag the $V$ meson decaying into the invisible final state. [...] OpenAccess: PDF; 2019-01-0317:27 [GSI-2019-00033] Journal Article et al Observation of $h_1(1380)$ in the $J / ψ → η^{\prime} K \bar{K} π$ decay Physical review / D D 98(7), 072005 (2018) [10.1103/PhysRevD.98.072005] Using $1.31 \times 10^9$ $J/\psi$ events collected by the BESIII detector at the BEPCII $e^+e^-$ collider, we report the first observation of the $h_1(1380)$ in $J/\psi \to \eta^{\prime} h_1(1380)$ with a significance of more than ten standard deviations. The mass and width of the possible axial-vector strangeonium candidate $h_1(1380)$ are measured to be $M = (1423.2 \pm 2.1 \pm 7.3)$ MeV and $\Gamma = (90.3 \pm 9.8 \pm 17.5)$ MeV. [...] OpenAccess: PDF; 2019-01-0317:10 [GSI-2019-00031] Journal Article et al Observation of $ψ$(3686) $→η′e^+e^−$ Physics letters / B B 783, 452 - 458 (2018) [10.1016/j.physletb.2018.05.038] Using a data sample of $448.1 \times 10^6$ $\psi(3686)$ events collected with the BESIII detector at the BEPCII collider, we report the first observation of the electromagnetic Dalitz decay $\psi(3686) \to \eta' e^+ e^-$, with significances of 7.0$\sigma$ and 6.3$\sigma$ when reconstructing the $\eta'$ meson via its decay modes $\eta'\to\gamma \pi^+ \pi^-$ and $\eta'\to\pi^+\pi^-\eta$ ($\eta \to \gamma\gamma$), respectively. The weighted average branching fraction is determined to be $\mathcal{B}(\psi(3686) \to \eta' e^+ e^-)= (1.90 \pm 0.25 \pm 0.11) \times 10^{-6}$, where the first uncertainty is statistical and the second systematic.. OpenAccess: PDF; 2019-01-0316:56 [GSI-2019-00029] Journal Article et al Measurement of singly Cabibbo-suppressed decays $D^0 → π^0 π^0 π^0 , π^0 π^0 η , π^0 ηη$ and $ηηη$ Physics letters / B B 781, 368 - 375 (2018) [10.1016/j.physletb.2018.04.017] Using a data sample of $e^+e^-$ collision data corresponding to an integrated luminosity of 2.93 $fb^{-1}$ collected with the BESIII detector at a center-of-mass energy of $\sqrt{s}= 3.773~GeV$,we search for the singly Cabibbo-suppressed decays $D^{0}\to\pi^{0}\pi^{0}\pi^{0}$, $\pi^{0}\pi^{0}\eta$, $\pi^{0}\eta\eta$ and $\eta\eta\eta$ using the double tag method. The absolute branching fractions are measured to be $\mathcal{B}(D^{0}\to\pi^{0}\pi^{0}\pi^{0}) = (2.0 \pm 0.4 \pm 0.3)\times 10^{-4}$, $\mathcal{B}(D^{0}\to\pi^{0}\pi^{0}\eta) = (3.8 \pm 1.1 \pm 0.7)\times 10^{-4}$ and $\mathcal{B}(D^{0}\to\pi^{0}\eta\eta) = (7.3 \pm 1.6 \pm 1.5)\times 10^{-4}$ with the statistical significances of $4.8\sigma$, $3.8\sigma$ and $5.5\sigma$, respectively, where the first uncertainties are statistical and the second ones systematic. [...] OpenAccess: PDF; 2019-01-0316:51 [GSI-2019-00028] Journal Article et al Measurement of the Absolute Branching Fraction of the Inclusive Decay $Λ_{c}^+ → Λ + X$ Physical review letters 121(6), 062003 (2018) [10.1103/PhysRevLett.121.062003] Based on an $e^+e^-$ collision data sample corresponding to an integrated luminosity of 567$\,\rm{pb}^{-1}$ taken at the center-of-mass energy of $\sqrt{s} = 4.6$ GeV with the BESIII detector, we measure the absolute branching fraction of the inclusive decay $\Lambda_{c}^{+} \to \Lambda + X$ to be $\mathcal{B}(\Lambda_{c}^{+} \to \Lambda + X)=(38.2^{+2.8}_{-2.2}\pm0.8)\%$ using the double-tag method, where $X$ refers to any possible final state particles. In addition, we search for direct CP violation in the charge asymmetry of this inclusive decay for the first time, and obtain $\mathcal{A}_{CP} \equiv \frac{\mathcal{B}(\Lambda_{c}^{+} \to \Lambda + X)-\mathcal{B}(\bar{\Lambda}_{c}^{-} \to \bar{\Lambda} + X)}{\mathcal{B}(\Lambda_{c}^{+} \to \Lambda + X)+\mathcal{B}(\bar{\Lambda}_{c}^{-} \to \bar{\Lambda} + X)} = (2.1^{+7.0}_{-6.6}\pm1.4)\%$, a statistically limited result with no evidence of CP violation.. OpenAccess: PDF;