Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userObservation of the Dalitz Decay $D_{s}^{*+} to D_{s}^{+} e^{+} e^{-}$
146
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
Using 586 $textrm{pb}^{-1}$ of $e^{+}e^{-}$ collision data acquired at $sqrt{s}=4.170$ GeV with the CLEO-c detector at the Cornell Electron Storage Ring, we report the first observation of $D_{s}^{*+} to D_{s}^{+} e^{+} e^{-}$ with a significance of $5.3 sigma$. The ratio of branching fractions $calB(D_{s}^{*+} to D_{s}^{+} e^{+} e^{-}) / calB(D_{s}^{*+} to D_{s}^{+} gamma)$ is measured to be $[ 0.72^{+0.15}_{-0.13} (textrm{stat}) pm 0.10 (textrm{syst})]%$, which is consistent with theoretical expectations.
rate research
Read More
Using a $3.19~mathrm{fb}^{-1}$ data sample collected at the $sqrt{s}~=~4.178$ GeV with the BESIII detector, we search for the rare decay $D_{s}^{+} rightarrow p bar{p} e^{+} u_{e} $. No significant signal is observed, and an upper limit of $mathcal{B}(D_{s}^{+} rightarrow p bar{p} e^{+} u_{e}) < 2.0 times 10^{-4}$ is set at the 90% confidence level. This measurement is useful input in understanding the baryonic transition of $D_{s}^{+}$ mesons.
We study $D_{s}^{+}$ decays to final states involving the $eta$ with a 482$,$pb$^{-1}$ data sample collected at $sqrt{s}$ = 4.009$,$GeV with the mbox{BESIII} detector at the BEPCII collider. We measure the branching fractions $mathcal{B}(D^+_{s}rightarrow etaX)$ = (8.8$pm$1.8$pm$0.5)$%$ and $mathcal{B}(D_{s}^{+}rightarrow etarho^{+})$ = ($5.8pm1.4pm0.4$)$%$ where the first uncertainty is statistical and the second is systematic. In addition, we estimate an upper limit on the non-resonant branching ratio $mathcal{B}(D_{s}^{+}rightarrow etapi^+pi^0)<5.1%$ at the 90$%$ confidence level. Our results are consistent with CLEOs recent measurements and help to resolve the disagreement between the theoretical prediction and CLEOs previous measurement of $mathcal{B}(D_{s}^{+}rightarrow etarho^{+})$.
By analyzing 482 pb$^{-1}$ of $e^+e^-$ collision data collected at $sqrt s=4.009$ GeV with the BESIII detector at the BEPCII collider, we measure the absolute branching fractions for the semileptonic decays $D_{s}^{+}toeta e^{+} u_{e}$ and $D_{s}^{+}to etae^{+} u_{e}$ to be ${B}(D_{s}^{+}rightarroweta e^{+} u_{e})=(2.30pm0.31pm0.08)$% and ${B}(D_{s}^{+}rightarrowetae^{+} u_{e}) = (0.93pm0.30pm0.05)$%, respectively, and their ratio $frac{{B}(D_{s}^{+}rightarrowetae^{+} u_{e})} {{B}(D_{s}^{+}rightarroweta e^{+} u_{e})}=0.40pm0.14pm0.02$, where the first uncertainties are statistical and the second ones are systematic. The results are in good agreement with previous measurements within uncertainties; they can be used to determine the $eta-eta$ mixing angle and improve upon the $D_s^+$ semileptonic branching ratio precision.
We report the first observation of the Dalitz decay $eta to gamma e^+e^-$, based on a data sample of 1.31 billion $J/psi$ events collected with the BESIII detector. The $eta$ mesons are produced via the $J/psi to gamma eta$ decay process. The ratio $Gamma(eta to gamma e^+ e^-)/Gamma(etatogammagamma)$ is measured to be $(2.13pm0.09(text{stat.})pm0.07(text{sys.}))times10^{-2}$. This corresponds to a branching fraction ${cal B}(eta to gamma e^+e^-)= (4.69 pm0.20(text{stat.})pm0.23(text{sys.}))times10^{-4}$. The transition form factor is extracted and different expressions are compared to the measured dependence on the $e^+e^-$ invariant mass. The results are consistent with the prediction of the Vector Meson Dominance model.
The branching fraction of the decay $B_{s}^{0} rightarrow D_{s}^{(*)+}D_{s}^{(*)-}$ is measured using $pp$ collision data corresponding to an integrated luminosity of $1.0fb^{-1}$, collected using the LHCb detector at a centre-of-mass energy of $7$TeV. It is found to be begin{align*} {mathcal{B}}(B_{s}^{0}rightarrow~D_{s}^{(*)+}D_{s}^{(*)-}) = (3.05 pm 0.10 pm 0.20 pm 0.34)%, end{align*} where the uncertainties are statistical, systematic, and due to the normalisation channel, respectively. The branching fractions of the individual decays corresponding to the presence of one or two $D^{*pm}_{s}$ are also measured. The individual branching fractions are found to be begin{align*} {mathcal{B}}(B_{s}^{0}rightarrow~D_{s}^{*pm}D_{s}^{mp}) = (1.35 pm 0.06 pm 0.09 pm 0.15)%, ewline{mathcal{B}}(B_{s}^{0}rightarrow~D_{s}^{*+}D_{s}^{*-}) = (1.27 pm 0.08 pm 0.10 pm 0.14)%. end{align*} All three results are the most precise determinations to date.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
