Based on $e^+e^-$ annihilation data samples collected with the BESIII detector at the BEPCII collider at 13 center of mass energies from 4.008 to 4.600 GeV, measurements of the Born cross section of $e^{+}e^{-}rightarrow p bar{p} pi^{0}$ are performed. No significant resonant structure is observed in the measured energy-dependent cross section. The upper limit on the Born cross section of $e^{+}e^{-}rightarrow Y(4260) rightarrow p bar{p} pi^{0}$ at the 90% C.L. is determined to be 0.01 pb.
Using data samples collected with the BESIII detector at the BEPCII collider at six center-of-mass energies between 4.008 and 4.600 GeV, we observe the processes $e^+e^-rightarrow phiphiomega$ and $e^+e^-rightarrow phiphiphi$. The Born cross sections are measured and the ratio of the cross sections $sigma(e^+e^-rightarrow phiphiomega)/sigma(e^+e^-rightarrow phiphiphi)$ is estimated to be $1.75pm0.22pm0.19$ averaged over six energy points, where the first uncertainty is statistical and the second is systematic. The results represent first measurements of these interactions.
Based on $14.7~textrm{fb}^{-1}$ of $e^+e^-$ annihilation data collected with the BESIII detector at the BEPCII collider at 17 different center-of-mass energies between $3.7730~textrm{GeV}$ and $4.5995~textrm{GeV}$, Born cross sections of the two processes $e^+e^- to pbar{p}eta$ and $e^+e^- to pbar{p}omega$ are measured for the first time. No indication of resonant production through a vector state $V$ is observed, and upper limits on the Born cross sections of $e^+e^- to V to pbar{p}eta$ and $e^+e^- to V to pbar{p}omega$ at the $90%$ confidence level are calculated for a large parameter space in resonance masses and widths. For the current world average parameters of the $psi(4230)$ of $m=4.2187~textrm{GeV}/c^{2}$ and $Gamma=44~textrm{MeV}$, we find upper limits on resonant production of the $pbar{p}eta$ and $pbar{p}omega$ final states of $7.5~textrm{pb}$ and $10.4~textrm{pb}$ at the $90%$ CL, respectively.
Using data samples collected with the BESIII detector operating at the BEPCII collider at center-of-mass energies from 3.810 to 4.600 GeV, we perform a study of $e^{+}e^{-} to eta J/psi$ and $pi^0 J/psi$. Statistically significant signals of $e^{+}e^{-} to eta J/psi$ are observed at $sqrt{s}$ = 4.190, 4.210, 4.220, 4.230, 4.245, 4.260, 4.360 and 4.420 GeV, while no signals of $e^{+}e^{-} to pi^{0} J/psi$ are observed. The measured energy-dependent Born cross section for $e^{+}e^{-} to eta J/psi$ shows an enhancement around 4.2~GeV. The measurement is compatible with an earlier measurement by Belle, but with a significantly improved precision.
We investigate the process $e^{+}e^{-} rightarrow Kbar{K}J/psi$ at center-of-mass energies from 4.189 to 4.600 GeV using 4.7 fb$^{-1}$ of data collected by the BESIII detector at the BEPCII collider. The Born cross sections for the reactions $e^{+}e^{-} rightarrow K^{+}K^{-}J/psi$ and $K_{S}^{0} K_{S}^{0} J/psi$ are measured as a function of center-of-mass energy. The energy dependence of the cross section for $e^{+}e^{-} rightarrow K^{+}K^{-}J/psi$ is shown to differ from that for $pi^{+}pi^{-}J/psi$ in the region around the $Y(4260)$. In addition, there is evidence for a structure around 4.5 GeV in the $e^{+}e^{-} rightarrow K^{+}K^{-}J/psi$ cross section that is not present in $pi^{+}pi^{-}J/psi$.
Using data taken at 23 center-of-mass energies between 4.0 and 4.6 GeV with the BESIII detector at the BEPCII collider and with a total integrated luminosity of approximately $15$ fb$^{-1}$, the process $e^+e^-to 2(p bar{p})$ is studied for the first time. The Born cross sections for $e^+e^-to 2(p bar{p})$ are measured, and no significant structure is observed in the lineshape. The baryon pair ($pp$ and $bar{p}bar{p}$) invariant mass spectra are consistent with phase space, therefore no hexaquark or di-baryon state is found.
M. Ablikim
,M. N. Achasov
,S. Ahmed
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(2017)
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"Cross section measurements of $e^{+}e^{-}rightarrow p bar{p} pi^{0}$ at center-of-mass energies between 4.008 and 4.600 GeV"
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Xiaocong Ai
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