Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userObservation of di-structures in $e^+e^-rightarrow{J}/psi{rm X}$ at center-of-mass energies around 3.773 GeV
182
0
0.0
(
0
)
Authors
M. Ablikim
Ask ChatGPT about the research
No Arabic abstract
We report a measurement of the observed cross sections of the inclusive $J/psi$ production in $e^+e^-rightarrow {J}/psi{rm X}$ based on 3.21 fb$^{-1}$ of data accumulated at energies from 3.645 to 3.891 GeV with the BESIII detector operated at the BEPCII collider. The energy-dependent lineshape obtained from the measured cross sections cannot be well described by two Breit-Wigner (BW) amplitudes of the expected decays $psi(3686)rightarrow {J}/psi{rm X}$ and $psi(3770)rightarrow {J}/psi{rm X}$. Instead it can be better described with three BW amplitudes of the decays $psi(3686)rightarrow {J}/psi{rm X}$, $R(3760)rightarrow {J}/psi{rm X}$ and $R(3790)rightarrow {J}/psi{rm X}$ with two distinct structures referred to as $R(3760)$ and $R(3790)$. Under this assumption, we extracted their masses, total widths, and the product of the leptonic width and decay branching fractions to be $M_{R(3760)}= {3761.7pm 2.2 pm 1.2}$ MeV/$c^2$, $Gamma^{rm tot}_{R(3760)}= {6.7pm 11.1 pm 1.1}$ MeV, $Gamma^{ee}_{R(3760)}mathcal B[R(3760)rightarrow {J}/psi {rm X}]=(4.0pm 4.3pm 1.2)$ eV, $M_{R(3790)} = {3784.7pm 5.7 pm 1.6}$ MeV/$c^2$, $Gamma^{rm tot}_{R(3790)} = {31.6 pm 11.9 pm 3.2}$ MeV, $Gamma^{ee}_{R(3790)}mathcal B[R(3790)rightarrow {J}/psi {rm X}]=(18.1pm 10.3pm 4.7)$ eV, where the first uncertainties are statistical and second systematic.
rate research
Read More
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 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.
Using a 478 pb$^{-1}$ data sample collected with the BESIII detector operating at the BEPCII storage ring at a center-of-mass energy of $sqrt{s}=4.009$ GeV, the production of $e^{+}e^{-}to eta Jpsi$ is observed for the first time with a statistical significance of greater than $10sigma$. The Born cross section is measured to be $(32.1pm 2.8 pm 1.3)$ pb, where the first error is statistical and the second systematic. Assuming the $eta Jpsi$ signal is from a hadronic transition of the $psi(4040)$, the fractional transition rate is determined to be ${cal B}(psi(4040)to eta Jpsi)=(5.2pm 0.5pm 0.2pm 0.5)times 10^{-3}$, where the first, second, and third errors are statistical, systematic, and the uncertainty from the $psi(4040)$ resonant parameters, respectively. The production of $e^{+}e^{-} to pi^0 Jpsi$ is searched for, but no significant signal is observed, and ${cal B}(psi(4040)to pi^0 Jpsi) < 2.8 times 10^{-4}$ is obtained at the 90% confidence level.
Using $4.479 times 10^{8}$ $psi(3686)$ events collected with the BESIII detector, we search for the decays $psi(3686) rightarrow e^{+}e^{-}chi_{c0,1,2}$ and $chi_{c0,1,2} rightarrow e^{+}e^{-}J/psi$. The decays $psi(3686) rightarrow e^{+}e^{-}chi_{c0,1,2}$ and $chi_{c0,1,2} rightarrow e^{+}e^{-}J/psi$ are observed for the first time. The measured branching fractions are $mathcal{B}(psi(3686) rightarrow e^{+}e^{-}chi_{c0,1,2}) = (11.7 pm 2.5 pm 1.0)times10^{-4}$, $(8.6 pm 0.3 pm 0.6)times10^{-4}$, $(6.9 pm 0.5 pm 0.6)times10^{-4}$, and $mathcal{B}(chi_{c0,1,2} rightarrow e^{+}e^{-}J/psi) = (1.51 pm 0.30 pm 0.13)times10^{-4}$, $(3.73 pm 0.09 pm 0.25)times10^{-3}$, $(2.48 pm 0.08 pm 0.16)times10^{-3}$. The ratios of the branching fractions $frac{mathcal{B}(psi(3686) rightarrow e^{+}e^{-}chi_{c0,1,2})}{mathcal{B}(psi(3686) rightarrow gammachi_{c0,1,2})}$ and $frac{mathcal{B}(chi_{c0,1,2} rightarrow e^{+}e^{-}J/psi)}{mathcal{B}(chi_{c0,1,2} rightarrow gamma J/psi)}$ are also reported.
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.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
