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 root s = 3.773 GeV, we search ...for the singly Cabibbo-suppressed decays D-0 -> 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 B(D-0 -> pi(0)pi(0)pi(0)) = (2.0 +/- 0.4 +/- 0.3) x 10(-4), B(D-0 -> pi(0)pi(0)eta) = (3.8 +/- 1.1 +/- 0.7) x 10(-4) and B(D-0 -> pi(0)eta eta) = (7.3 +/- 1.6 +/- 1.5) x 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. No significant signal of D-0 -> eta eta eta is found, and the upper limit on its decay branching fraction is set to be B(D-0 -> eta eta eta) < 1.3 x 10(-4) at the 90% confidence level.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Abstract
The cross sections of
at center-of-mass energies from 4.127 to 4.600 GeV are measured based on 15.6 fb
data collected with the BESIII detector operating at the BEPCII storage ring. Two ...resonant structures are observed in the line shape of the cross sections. The mass and width of the first structure are measured to be (
) MeV and (
) MeV, respectively. They are consistent with those of the established
. The second structure is observed for the first time with a statistical significance greater than 8
σ
, denoted as
. Its mass and width are determined to be (
) MeV and (
) MeV, respectively. The first presented uncertainties are statistical and the second ones are systematic. The product of the electronic partial width with the decay branching fraction
is reported.
Using a sample of 448.1×106 ψ(3686) events collected with the BESIII detector in 2009 and 2012, we study the decays χc0,2 → η'η' and ηη' . The decays χc2 → η'η' , χc0 → ηη' and χc2 → ηη' are observed ...for the first time with statistical significances of 9.6 , 13.4 and 7.5 , respectively. The branching fractions are determined to be B( χc0 → η'η' ) = (2.19 ± 0.03 ± 0.14) × 10-3, B( χc2 → η'η' ) = (4.76 ± 0.56 ± 0.38) × 10-5, B( χc0 → ηη' ) = (8.92±0.84±0.65)×10-5 and B( χc2 → ηη' ) = (2.27±0.43±0.25)×10-5 , where the first uncertainties are statistical and the second are systematic. The precision for the measurement of B( χc0 → η'η' ) is significantly improved compared to previous measurements. Based on the measured branching fractions, the role played by the doubly and singly Okubo-Zweig-Iizuka disconnected transition amplitudes for χc0,2 decays into pseudoscalar meson pairs can be clarified.
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CMK, CTK, FMFMET, IJS, NUK, PNG, UM
We search for the di-photon decay of a light pseudoscalar axion-like particle, \(a\), in radiative \(J/\psi\) decays, using 10 billion \(J/\psi\) events collected with the BESIII detector. We find no ...evidence of a signal and set upper limits at the \(95\%\) confidence level on the product branching fraction \(\mathcal{B}(J/\psi \to \gamma a) \times \mathcal{B}(a \to \gamma \gamma)\) and the axion-like particle photon coupling constant \(g_{a \gamma \gamma}\) in the ranges of \((3.7-48.5) \times 10^{-8}\) and \((2.2 -101.8)\times 10^{-4}\) GeV\(^{-1}\), respectively, for \(0.18 \le m_a \le 2.85\) GeV/\(c^2\). These are the most stringent limits to date in this mass region.
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