Do you want to publish a course? Click here

Measurement of the $e^{+}e^{-} to eta J/psi$ cross section and search for $e^{+}e^{-} to pi^{0} J/psi$ at center-of-mass energies between 3.810 and 4.600~GeV

152   0   0.0 ( 0 )
 Added by Zhihong Wang
 Publication date 2015
  fields
and research's language is English




Ask ChatGPT about the research

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.



rate research

Read More

The process $e^{+}e^{-}to eta^{prime} J/psi$ is observed for the first time with a statistical significance of $8.6sigma$ at center-of-mass energy $sqrt{s} = 4.226$ GeV and $7.3sigma$ at $sqrt{s} = 4.258$ GeV using data samples collected with the BESIII detector. The Born cross sections are measured to be $(3.7 pm 0.7 pm 0.3)$ and $(3.9 pm 0.8 pm 0.3)$ pb at $sqrt{s} = 4.226$ and $4.258$ GeV, respectively, where the first errors are statistical and the second systematic. Upper limits at the 90% confidence level of the Born cross sections are also reported at other 12 energy points.
The cross section for the process $e^+e^-to pi^+pi^-J/psi$ is measured precisely at center-of-mass energies from 3.77 to 4.60~GeV using 9~fb$^{-1}$ of data collected with the BESIII detector operating at the BEPCII storage ring. Two resonant structures are observed in a fit to the cross section. The first resonance has a mass of $(4222.0pm 3.1pm 1.4)$~MeV/$c^2$ and a width of $(44.1pm 4.3pm 2.0)$~MeV, while the second one has a mass of $(4320.0pm 10.4 pm 7.0)$~MeV/$c^2$ and a width of $(101.4^{+25.3}_{-19.7}pm 10.2)$~MeV, where the first errors are statistical and second ones are systematic. The first resonance agrees with the $Y(4260)$ resonance reported by previous experiments. The precision of its resonant parameters is improved significantly. The second resonance is observed in $e^+e^-to pi^+pi^-J/psi$ for the first time. The statistical significance of this resonance is estimated to be larger than $7.6sigma$. The mass and width of the second resonance agree with the $Y(4360)$ resonance reported by the $BABAR$ and Belle experiments within errors. Finally, the $Y(4008)$ resonance previously observed by the Belle experiment is not confirmed in the description of the BESIII data.
We have measured several branching ratios for $psi^prime$ decay using the data collected by FNAL E835 experiment during year 2000, obtaining ${cal B}(psi^prime to e^+ e^-) = 0.0068pm0.0001pm0.0004$, ${cal B}(psi^prime to J/psi pi^+ pi^-) = 0.292pm0.005pm0.018$, ${cal B}(psi^prime to J/psi pi^0 pi^0) = 0.167pm0.005pm0.014$ and ${cal B}(psi^prime to J/psi eta) = 0.028pm0.002pm0.002$. We also present a measurement of the dipion mass distribution in the decays $psi^prime to J/psi pi pi$.
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 $pi^{+}pi^{-}J/psi$.
The cross section for e^+e^- to pi^+pi^-J/psi between 3.8 and 5.5 GeV/c^2 is measured using a 548 fb^{-1} data sample collected on or near the Upsilon(4S) resonance with the Belle detector at KEKB. A peak near 4.25 GeV/c^2, corresponding to the so called Y(4260), is observed. In addition, there is another cluster of events at around 4.05 GeV/c^2. A fit using two interfering Breit-Wigner shapes describes the data better than one that uses only the Y(4260), especially for the lower mass side of the 4.25 GeV enhancement.
comments
Fetching comments Fetching comments
Sign in to be able to follow your search criteria
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا