Using a data sample of 448×106 ψ(3686) events collected with the BESIII detector operating at the BEPCII storage ring, the decays ψ(3686)→γη and ψ(3686)→γπ0 are observed with a statistical ...significance of 7.3σ and 6.7σ, respectively. The branching fractions are measured to be B(ψ(3686)→γη)=(0.85±0.18±0.05)×10−6 and B(ψ(3686)→γπ0)=(0.95±0.16±0.05)×10−6. In addition, we measure the branching fraction of ψ(3686)→γη′ to be B(ψ(3686)→γη′)=(125.1±2.2±6.2)×10−6, which represents an improvement of precision over previous results.
We address new measurements of Cabibbo-suppressed semileptonic D$+\atop{s}$ decays using 3.19 fb-1 of e+e- annihilation data sample collected at a center-of-mass energy of 4.178 GeV with the BESIII ...detector at the BEPCII collider. Our results include branching fractions $\mathcal{B(D^+_s→K^0e^+v_e)}$ = (3.25 ± 0.38(stat.) ± 0.16(syst.))×10-3 and $\mathcal{B(D^+_s→K*^0e^+v_e)}$ = (2.37±0.26(stat.)±0.20(syst.))×10-3 which are much improved relative to previous measurements, and the first measurements of the hadronic form-factor parameters for these decays. For D$+\atop{s}$→K0e+ve, we obtain f+(0) = 0.720 ± 0.084(stat.) ± 0.013(syst.), and for D$+\atop{s}$→K*0e+ve, we find form-factor ratios rV = V (0)/A1(0) = 1.67 ± 0.34(stat.) ± 0.16(syst.) and r2 = A2(0)/A1(0) = 0.77 ± 0.28(stat.) ± 0.07(syst.).
We study the decays Λ+c → Ληπ+ and Σ(1385)+η based on Λ+cΛ¯c pairs produced in e+e– collisions at a center-of-mass energy of √s = 4.6 GeV, corresponding to an integrated luminosity of 567 pb–1.The ...data sample was accumulated with the BESIII detector at the BEPCII collider. The branching fractions are measured to be B(Λ+c → Ληπ+) = (1.84 ± 0.21(stat) ± 0.15(syst))% and B(Λ+c → Σ(1385)+η) = (0.91 ± 0.18(stat) ± 0.09(syst))%, constituting the most precise measurements to date.
The baryonic decay D$+\atop{s}$→p$\overline{n}$ is examined, and the corresponding branching fraction is measured to be (1.21 ± 0.10 ± 0.05 ) × 10-3 , where the first uncertainty is statistical and ...second systematic. The data sample used in this analysis was collected with the BESIII detector operating at the BEPCII e+e- double-ring collider with a center-of-mass energy of 4.178 GeV and an integrated luminosity of 3.19 fb-1 . The result corroborates the previous measurement by the CLEO Collaboration and is of greatly improved precision. This result will improve our understanding of the dynamical enhancement of the W-annihilation topology in the charmed meson decays.
We observe the process ψ(3686)→p$\overline{p}$η' for the first time, with a statistical significance higher than 10σ, and measure the branching fraction of J/ψ→p$\overline{p}$η' with an improved ...accuracy compared to earlier studies. The measurements are based on 4.48 × 108 ψ(3686) and 1.31 × 109 J/ψ events collected by the BESIII detector operating at the BEPCII. The branching fractions are determined to be $\mathcal{B(ψ(3686)→p\overline{p}η')}$ = (1.10 ± 0.10 ± 0.08)×10-5 and $\mathcal{B(J/ψ →p\overline{p}η')}$ = (1.26 ± 0.02 ± 0.07) ×10-4, where the first uncertainties are statistical and the second ones systematic. Also, the η- η' mixing angle is determined to be -24° ± 11° based on ψ(3686)→p$\overline{p}$η', and -24° ± 9° based on J/ψ→p$\overline{p}$η', respectively.
A search for the rare radiative leptonic decay Ds+ → γe+νe is performed for the first time using electron-positron collision data corresponding to an integrated luminosity of 3.19 fb–1, collected ...with the BESIII detector at a center-of-mass energy of 4.178 GeV. No evidence for the Ds+ → γe+νe decay is seen, and an upper limit of B( Ds+ → γe+νe ) < 1.3 ×10–4 is set on the partial branching fraction at a 90% confidence level for radiative photon energies $E$ $^{*}_{γ}$ > 0.01 GeV.
Observation of ψ(3686)→η′e+e Ahmed, S.; Albrecht, M.; Bakina, O. ...
Physics letters. B,
08/2018, Letnik:
783, Številka:
C
Journal Article
Recenzirano
Odprti dostop
Using a data sample of 448.1×106ψ(3686) events collected with the BESIII detector at the BEPCII collider, we report the first observation of the electromagnetic Dalitz decay ψ(3686)→η′e+e−, with ...significances of 7.0σ and 6.3σ when reconstructing the η′ meson via its decay modes η′→γπ+π− and η′→π+π−η (η→γγ), respectively. The weighted average branching fraction is determined to be B(ψ(3686)→η′e+e−)=(1.90±0.25±0.11)×10−6, where the first uncertainty is statistical and the second systematic.
Decays $\mathcal{x_{cj}}$ (J = 0, 1, 2)→ωφ are studied using (448.1 ± 2.9) × 106ψ(3686) events collected with the BESIII detector in 2009 and 2012. Futhermore, In addition to the previously ...established $\mathcal{x_{c0}}$→ωΦ, the first observation of $\mathcal{x_{c1}}$→ωΦ is reported in this paper. The measured product branching fractions are $\mathcal{B(ψ(3686)→γχ_{c0}) × B(χ_{c0}→ωΦ)}$ = (13.83 ± 0.70 ± 1.01) × 10-6 and $\mathcal{B(ψ(3686)→γχ_{c1}) × B(χ_{c1}→ωΦ)}$ = (2.67 ± 0.31 ± 0.27) × 10-6, and the absolute branching fractions are $\mathcal{B(x_{c0}→ωΦ)}$ = (13.84 ± 0.70 ± 1.08) × 10-5 and $\mathcal{B(x_{c1}→ωΦ)}$ = (2.80 ± 0.32 ± 0.30) × 10-5. Furthermore, we find a strong evidence for $\mathcal{x_{c2}}$→ωΦ with a statistical significance of 4.8σ, and the corresponding product and absolute branching fractions are measured to be$\mathcal{B(ψ(3686)→γχ_{c2})×B(χ_{c2}→ωΦ)}$ = (0.91 ± 0.23 ± 0.12) × 10-6 and $\mathcal{B(x_{c2}→ωΦ)}$ = (1.00 ± 0.25 ± 0.14) × 10-5. Here, the first errors are statistical and the second ones systematic.
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