Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userStudy of $e^+e^-to Upsilon(rm1S,2S)eta$ and $e^+e^-to Upsilon(rm 1S)eta^{prime}$ at $sqrt{s}=10.866$ GeV with the Belle detector
153
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
We report the first observation of the processes $e^+e^-toUpsilon(rm 1S,2S)eta$ at $sqrt{s}=10.866$~GeV with a $10.2sigma$ and $16.5sigma$ significance respectively. The measured Born cross sections are $sigma(e^+e^- to Upsilon(2S)eta)=2.07 pm 0.21 pm 0.19$~pb, and $sigma(e^+e^- to Upsilon(rm 1S)eta)=0.42 pm 0.08 pm 0.04$~pb. We also set the upper limit on the cross section of the process $e^+e^- to Upsilon(rm 1S)eta^{prime}$ to be $sigma(e^+e^- to Upsilon(rm 1S)eta^{prime})<0.035$~pb at $90%$ CL. The results are obtained with the data sample collected with the Belle detector at the KEKB asymmetric-energy $e^+e^-$ collider in the energy range from $10.63$~GeV to $11.02$~GeV.
rate research
Read More
The first search for $Z_{c}$ pair production in $Upsilon(1S)$ and $Upsilon(2S)$ decays and in $e^{+}e^{-}$ annihilation at $sqrt{s}$ = 10.52, 10.58, and 10.867 GeV is conducted using data collected with the Belle detector at the KEKB asymmetric energy electron-positron collider. No significant signals are observed in any of the studied modes, and the 90% credibility level upper limits on their product branching fractions in $Upsilon(1S)$ and $Upsilon(2S)$ decays (${cal B}(Upsilon(1S,2S)to Z^{+}_{c}Z^{(prime) -}_{c})times{cal B}(Z^{+}_{c}topi^{+}+cbar c)$ ($cbar c=J/psi$, $chi_{c1}(1P)$, $psi(2S)$)) and the product of Born cross section and branching fraction for $e^{+}e^{-} to Z^{+}_{c}Z^{(prime) -}_{c}$ ($sigma(e^+e^- to Z^{+}_{c}Z^{(prime) -}_{c})times {cal B}(Z^{+}_{c} to pi^+ +cbar c)$) at $sqrt{s}$ = 10.52, 10.58, and 10.867 GeV are determined. Here, $Z_{c}$ refers to the $Z_{c}(3900)$ and $Z_{c}(4200)$ observed in the $pi J/psi$ final state, the $Z_{c1}(4050)$ and $Z_{c2}(4250)$ in the $pichi_{c1}(1P)$ state, and the $Z_{c}(4050)$ and $Z_{c}(4430)$ in the $pipsi(2S)$ state.
A search for the rare decay $eta^{prime} to e^+e^-$ has been performed with the SND detector at the VEPP-2000 $e^+e^-$ collider. The inverse reaction $e^+e^- to eta^{prime}$ and $eta^{prime}$ five decay chains have been used for this search. The upper limit $Gamma_{eta^{prime} to e^+e^-}<0.002$ eV at the 90% confidence level has been set. A sensitivity of SND in a search for $eta to e^+e^-$ decay has been studied. For this perpose we have analyzed a data sample with an integrated luminosity of 108 nb$^{-1}$ collected in the center-of-mass energy range 520-580 MeV. There are no background events for the reaction $e^+e^- to eta$ with decay $eta to pi^0pi^0pi^0$ have been found. In the absence of background, a sensitivity to $B(eta to e^+e^-)$ of 10$^{-6}$ can be reached during two weeks of VEPP-2000 operation.
We report the analysis of the three-body e+e- => B B-bar pi, B B*-bar pi, and B* B*-bar pi processes, including the first observation of the Zb+-(10610) =>[B B*-bar+c.c.]+- and Zb+-(10650) => [B*B*-bar]+- transitions. We measure visible cross sections for the three-body production of sigma_vis(e+e- => [B B*-bar+c.c.]+-pi-+=(11.2+-1.0(stat.)+-1.2(syst.)) pb and sigma_vis(e+e- => [B*B*-bar]+-pi-+)=(5.61+-0.73(stat.)+-0.66(syst.)) pb and set a 90% C.L. upper limit of sigma_vis(e+e- => [BB-bar]+-pi-+)<2.1 pb. The results are based on a 121.4 1/fb data sample collected with the Belle detector at a center-of-mass energy near the Y(5S) peak.
The process $e^{+}e^{-} to phi eta^{prime}$ has been studied for the first time in detail using data sample collected with the BESIII detector at the BEPCII collider at center of mass energies from 2.05 to 3.08 GeV. A resonance with quantum numbers $J^{PC}=1^{--}$ is observed with mass $M$ = (2177.5 $pm$ 4.8 (stat) $pm$ 19.5 (syst)) MeV/${ it{c}^{mathrm{2}}}$ and width $Gamma$ = (149.0 $pm$ 15.6 (stat) $pm$ 8.9 (syst)) MeV with a statistical significance larger than 10$sigma$. The observed structure could be identified with the $phi(2170)$, then the ratio of partial width between the $phi eta^{prime}$ by BESIII and $phi eta$ by BABAR is ($mathcal{B}^{R}_{phi eta}Gamma^{R}_{ee})/{(mathcal{B}^{R}_{phi eta^{prime}}Gamma^{R}_{ee})}$ = 0.23 $pm$ 0.10 (stat) $pm$ 0.18 (syst), which is smaller than the prediction of the $sbar{s}g$ hybrid models by several orders of magnitude.
A search for the process $e^+e^- to eta^prime$ has been performed with the SND detector at the VEPP-2000 $e^+e^-$ collider. The data were accumulated at the center-of-mass energy of $957.78pm 0.06$ MeV with an integrated luminosity of about 2.9 pb$^{-1}$. For reconstruction of the $eta^prime$ meson five decay chains have been used: $eta^{prime}toetapi^+pi^-$ followed by the $eta$ decays to $gammagamma$ and $3pi^0 $, and $eta^{prime} to etapi^0pi^0$ followed by the $eta$ decays to $pi^+pi^-pi^0$, $gammagamma$, and $3pi^0$. As a result, the upper limit has been set on the $eta^prime$ electronic width: $Gamma_{eta^{prime}to e^+e^-} < 0.0020$ eV at the 90% confidence level.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
