507 research outputs found

    Corrigendum to “Measurement of the e+e− → π+π− cross section between 600 and 900 MeV using initial state radiation” [Phys. Lett. B 753 (2016) 629–638]

    Get PDF
    In Ref. [1] the BESIII collaboration published a cross section measurement of the process e+e−→π+π− in the energy range between 600 and 900 MeV. In this corrigendum, we report a corrected evaluation of the statistical errors in terms of a fully propagated covariance matrix. The correction also yields a reduced statistical uncertainty for the hadronic vacuum polarization contribution to the anomalous magnetic moment of the muon, which now reads as aμππ,LO(600−900MeV)=(368.2±1.5stat±3.3syst)×10−10. The central values of the cross section measurement and of aμππ,LO, as well as the systematic uncertainties remain unchanged

    Observation of the J/ψJ/\psi and ψ(3686)\psi(3686) decays into ηΣ+Σˉ\eta\Sigma^{+}\bar{\Sigma}^{-}

    Full text link
    The decays J/ψηΣ+ΣˉJ/\psi\to\eta\Sigma^{+}\bar{\Sigma}{}^- and ψ(3686)ηΣ+Σˉ\psi(3686)\to\eta\Sigma^{+}\bar{\Sigma}{}^- are observed for the first time, using (10087±44)×106(10087 \pm 44)\times 10^{6} J/ψJ/\psi and (448.1±2.9)×106(448.1 \pm 2.9)\times 10^{6} ψ(3686)\psi(3686) events collected with the BESIII detector at the BEPCII collider. We determine the branching fractions of these two decays to be B(J/ψηΣ+Σˉ)=(6.34±0.21±0.37)×105{\cal B}(J/\psi\to\eta\Sigma^{+}\bar{\Sigma}{}^-)=(6.34 \pm 0.21 \pm 0.37)\times 10^{-5} and B(ψ(3686)ηΣ+Σˉ)=(9.59±2.37±0.61)×106{\cal B}(\psi(3686)\to\eta\Sigma^{+}\bar{\Sigma}{}^-)=(9.59 \pm 2.37 \pm 0.61)\times 10^{-6}, where the first uncertainties are statistical and the second are systematic. The ratio of these two branching fractions is determined to be B(ψ(3686)ηΣ+Σˉ)B(J/ψηΣ+Σˉ)=(15.1±3.8)%\frac{{\cal B}(\psi(3686)\to\eta\Sigma^{+}\bar{\Sigma}{}^-)}{{\cal B}(J/\psi\to\eta\Sigma^{+}\bar{\Sigma}{}^-)}=(15.1 \pm 3.8)\%, which is in agreement with the "12\% rule."Comment: 9 pages and 10 figure

    Observation of the electromagnetic Dalitz decay D∗0 →d0e+e-

    Get PDF

    Amplitude analysis of Ds+π+ππ+D_s^{+} \rightarrow \pi^{+} \pi^{-} \pi^{+}

    Full text link
    Utilizing the data set corresponding to an integrated luminosity of 3.193.19 fb1^{-1} collected by the BESIII detector at a center-of-mass energy of 4.178 GeV, we perform an amplitude analysis of the Ds+π+ππ+D_s^+\to\pi^+\pi^-\pi^+ decay. The sample contains 13,797 candidates with a signal purity of \sim80%. The amplitude and phase of the contributing ππ\pi\pi S{\cal S} wave are measured based on a quasi-model-independent approach, along with the amplitudes and phases of the P{\cal P} and D{\cal D} waves parametrized by Breit-Wigner models. The fit fractions of different intermediate decay channels are also reported.Comment: 14 pages, 6 figure

    Study of the doubly Cabibbo-suppressed decays Ds+K+K+πD^+_s\to K^+K^+\pi^- and Ds+K+K+ππ0D^+_s\to K^+K^+\pi^-\pi^0

    Full text link
    Based on 7.33 fb1^{-1} of e+ee^+e^- collision data collected at center-of-mass energies between 4.128 and 4.226 GeV with the BESIII detector, the experimental studies of the doubly Cabibbo-suppressed decays Ds+K+K+πD^+_s\to K^+K^+\pi^- and Ds+K+K+ππ0D^+_s\to K^+K^+\pi^-\pi^0 are reported. We determine the absolute branching fraction of Ds+K+K+πD^+_s\to K^+K^+\pi^- to be (1.230.25+0.28(stat)±0.06(syst){1.23^{+0.28}_{-0.25}}({\rm stat})\pm0.06({\rm syst})) ×104\times 10^{-4}. No significant signal of Ds+K+K+ππ0D^+_s\to K^+K^+\pi^-\pi^0 is observed and the upper limit on its decay branching fraction at 90\% confidence level is set to be 1.7×1041.7\times10^{-4}.Comment: 10 pages, 4 figures, 4 table

    Measurement of the inclusive branching fraction for ψ(3686)→KS 0+anything

    Get PDF
    Using 5.9 pb−1 of e+e− annihilation data collected at center-of-mass energies from 3.640 to 3.701 GeV with the BESIII detector at the BEPCII Collider, we measure the observed cross sections of e+e−→KS0X (where X=anything). From a fit to these observed cross sections with the sum of continuum and ψ(3686) and J/ψ Breit-Wigner functions and considering initial state radiation and the BEPCII beam energy spread, we obtain for the first time the product of ψ(3686) leptonic width and inclusive decay branching fraction Γψ(3686)eeB(ψ(3686)→KS0X)=(373.8±6.7±20.0) eV, and assuming Γψ(3686)ee is (2.33±0.04) keV from PDG value, we measure B(ψ(3686)→KS0X)=(16.04±0.29±0.90)%, where the first uncertainty is statistical and the second is systematic

    Measurement of the absolute branching fraction of the inclusive decay Ds+π+π+πXD_s^+\to \pi^+\pi^+\pi^- X

    Get PDF
    Using an e+ee^+ e^- collision data sample with a total integrated luminosity of 3.193.19 fb1^{-1} collected with the BESIII detector at a center-of-mass energy of 4.178 GeV, the branching fraction of the inclusive decay of the Ds+D_s^+ meson to final states including at least three charged pions is measured for the first time to be B(Ds+π+π+πX)=(32.81±0.35stat±0.82syst)%{\cal B}(D_s^+\to\pi^+ \pi^+ \pi^- X) = (32.81 \pm 0.35_{\rm stat} \pm {0.82_{\rm syst}})\%. In this measurement the charged pions from KS0K_S^0 meson decays are excluded. The partial branching fractions of Ds+π+π+πXD_s^+\to\pi^+ \pi^+ \pi^- X are also measured as a function of the π+π+π\pi^+ \pi^+ \pi^- invariant mass.Comment: 13 pages, 4 figure

    Search for an axion-like particle in J/ψJ/\psi radiative decays

    Full text link
    We search for an axion-like particle (ALP) aa through the process ψ(3686)π+πJ/ψ\psi(3686)\rightarrow\pi^+\pi^-J/\psi, J/ψγaJ/\psi\rightarrow\gamma a, aγγa\rightarrow\gamma\gamma in a data sample with (2708.1±14.5)×106(2708.1\pm14.5)\times10^6 ψ(3686)\psi(3686) events collected by the BESIII detector. No significant ALP signal is observed over the expected background, and the upper limits on the branching fraction of the decay J/ψγaJ/\psi\rightarrow\gamma a and the ALP-photon coupling constant gaγγg_{a\gamma\gamma} are set at the 95\% confidence level in the mass range of 0.165\leq m_a\leq2.84\,\mbox{GeV}/c^2. The limits on B(J/ψγa)\mathcal{B}(J/\psi\rightarrow\gamma a) range from 8.3×1088.3\times10^{-8} to 1.8×1061.8\times10^{-6} over the search region, and the constraints on the ALP-photon coupling are the most stringent to date for 0.165\leq m_a\leq1.468\,\mbox{GeV}/c^2.Comment: 10 pages, 5 figure

    Partial Wave Analysis of J/ψγγϕJ/\psi\rightarrow \gamma \gamma \phi

    Full text link
    Using a sample of (10087±44)×106(10087\pm44)\times10^{6} J/ψJ/\psi events collected with the BESIII detector at the BEPCII collider, a partial wave analysis on the decay γγϕ\gamma\gamma\phi is performed to investigate the intermediate resonances in J/ψγX,XγϕJ/\psi\rightarrow\gamma X, X\rightarrow\gamma\phi. The resonances f1(1285)f_{1}(1285), η(1405)\eta(1405), f1(1420)f_{1}(1420), f1(1510)f_{1}(1510), f2(1525)f_{2}(1525), X(1835)X(1835), f2(1950)f_{2}(1950), f2(2010)f_{2}(2010), f0(2200)f_{0}(2200) and ηc\eta_{c} are observed with statistical significance greater than 5σ\sigma. The product branching fractions B(J/ψγX,Xγϕ)\mathcal{B}(J/\psi\rightarrow\gamma X, X\rightarrow \gamma \phi) are reported. The resonance parameters of η(1405)\eta(1405) and X(1835)X(1835) are also measured

    First Observation of a Three-Resonance Structure in e+ee^+e^-\rightarrow{non-open} Charm Hadrons

    Full text link
    We report the measurement of the cross sections for e+ee^+e^-\rightarrow{nOCH} (nOCH stands for non-open charm hadrons) with improved precision at center-of-mass energies from 3.645 to 3.871 GeV. We observe for the first time a three-resonance structure in the energy-dependent lineshape of the cross sections, which are R(3760)\mathcal R(3760), R(3780)\mathcal R(3780) and R(3810)\mathcal R(3810) with significances of 9.4σ9.4\sigma, 15.7σ15.7\sigma, and 9.8σ9.8\sigma, respectively. The R(3810)\mathcal R(3810) is observed for the first time. We found two solutions in analysis of the cross sections. For solution I [solution II], we measure the mass, the total width and the product of electronic width and nOCH decay branching fraction to be (3805.8±1.1±2.7)(3805.8 \pm 1.1 \pm 2.7) [(3805.8±1.1±2.7)(3805.8 \pm 1.1 \pm 2.7)] MeV/c2c^2, (11.6±2.6±1.9)(11.6 \pm 2.6 \pm 1.9) [(11.5±2.5±1.8)(11.5 \pm 2.5 \pm 1.8)] MeV, and (10.8±3.2±2.3)(10.8\pm 3.2\pm 2.3) [(11.0±2.9±2.4)(11.0\pm 2.9\pm 2.4)] eV for the R(3810)\mathcal R(3810), respectively. In addition, we measure the branching fractions B(R(3760){\mathcal B}({\mathcal R}(3760)\rightarrow{nOCH})=(24.5±13.4±27.4)%[(6.8±5.4±7.6)%])=(24.5 \pm 13.4 \pm 27.4)\% [(6.8 \pm 5.4 \pm 7.6)\%] for the first time, and B(R(3780){\mathcal B}(\mathcal R(3780)\rightarrow{nOCH})=(11.6±5.8±7.8)%[(10.3±4.5±6.9)%])=(11.6 \pm 5.8 \pm 7.8)\% [(10.3 \pm 4.5 \pm 6.9)\%]. Moreover, we determine the open-charm (OC) branching fraction B(R{\mathcal B}({\mathcal R}(3760)(3760)\rightarrow{OC})=(75.5±13.4±27.4)%[(93.2±5.4±7.6)%])=(75.5 \pm 13.4 \pm 27.4)\% [(93.2 \pm 5.4 \pm 7.6)\%], which supports the interpretation of R(3760)\mathcal R(3760) as an OC pair molecular state, but contained a simple four-quark state component. The first uncertainties are from fits to the cross sections, and the second are systematic
    corecore