0000000001062345
AUTHOR
F. De~mori
Measurement of the doubly Cabibbo-suppressed decay $D^+\to K^+��^+��^-��^0$ with semileptonic tags
Using an $e^+e^-$ annihilation data sample corresponding to an integrated luminosity of $2.93\,\rm fb^{-1}$ collected at a center-of-mass energy of 3.773 GeV with the BESIII detector, the doubly Cabibbo-suppressed decay $D^+\to K^+��^+��^-��^0$ is studied with a semileptonic tag method. After removing the decays containing narrow intermediate resonances, $D^+\to K^+��$, $D^+\to K^+��$, and $D^+\to K^+��$, the branching fraction for the decay $D^+\to K^+��^+��^-��^0$ is determined to be $(1.03 \pm 0.12_{\rm stat} \pm 0.06_{\rm syst})\times 10^{-3}$. The ratio of the branching fraction for $D^+\to K^+��^+��^-��^0$ to its Cabibbo-favored counterpart $D^+\to K^-��^+��^+��^0$ is measured to be $…
Measurement of the $e^{+}e^{-}\rightarrow����^{0}��^{0}$ cross section at center-of-mass energies from 2.0 to 3.08 GeV
The cross section of the process $e^{+}e^{-}\rightarrow����^{0}��^{0}$ is measured at nineteen center-of-mass energies from 2.0 to 3.08 GeV using data collected with the BESIII detector at the BEPCII storage ring. A resonant structure around 2.20 GeV is observed with significance larger than 5$��$. Using a coherent fit to the cross section line shape, the mass and width are determined to be $M=2223\pm16\pm11~{\rm MeV}/c^2$ and $\varGamma=51\pm29\pm21~{\rm MeV}$, respectively, where the first uncertainties are statistical and the second ones are systematic.
Observation of $D^0\to K_1(1270)^- e^+\nu_e$
Using 2.93 fb$^{-1}$ of $e^+e^-$ collision data taken with the BESIII detector at a center-of-mass energy of 3.773 $\rm \,GeV$, the observation of the $D^0\to K_1(1270)^- e^+\nu_e$ semileptonic decay is presented. The statistical significance of the decay $D^0\to K_1(1270)^- e^+\nu_e$ is greater than $10\sigma$. The branching fraction of $D^0\to K_1(1270)^- e^+\nu_e$ is measured to be $(1.09\pm0.13^{+0.09}_{-0.16} \pm 0.12)\times10^{-3}$. Here, the first uncertainty is statistical, the second is systematic, and the third originates from the assumed branching fraction of $K_1(1270)^- \rightarrow K^-\pi^+\pi^-$. The fraction of longitudinal polarization in $D^0\to K_1(1270)^- e^+\nu_e$ is det…
Search for the decay $D_s^+\to a_0(980)^0e^+\nu_e$
Using 6.32 fb$^{-1}$ of electron-positron collision data recorded by the BESIII detector at center-of-mass energies between 4.178 and 4.226~GeV, we present the first search for the decay $D_s^+\to a_0(980)^0 e^+\nu_e,\,a_0(980)^0\rightarrow \pi^0\eta$, which could proceed via $a_0(980)$-$f_0(980)$ mixing. No significant signal is observed. An upper limit of $1.2 \times 10^{-4}$ at the $90\%$ confidence level is set on the product of the branching fractions of $D_{s}^{+}\to a_0(980)^0 e^+\nu_e$ and $a_0(980)^0\rightarrow \pi^0\eta$ decays.