The numbers of $\psi(3686)$ events accumulated by the BESIII detector for the
two rounds of data taking during 2009 and 2012 are determined to be
$(107.0\pm0.8)\times 10^6$ and $(341.1\pm 2.1)\times ...10^6$, respectively, by
counting inclusive hadronic events, where the uncertainty is dominated by
systematics and the statistical uncertainty is negligible. The number of events
for the sample taken in 2009 is consistent with that of the previous
measurement. The total number of $\psi(3686)$ events for the two data-taking
periods is $(448.1\pm2.9)\times10^6$.
Phys. Rev. D 96 (2017) 092002 We search for the rare decay $D^+\to D^0 e^+\nu_{e}$, using a data set with
an integrated luminosity of 2.93 $\rm fb^{-1}$ collected at $\sqrt{s}=3.773$
GeV with the ...BESIII detector operating at the BEPCII storage rings. No signals
are observed. We set the upper limit on the branching fraction for $D^+\to D^0
e^+\nu_e$ to be $1.0\times 10^{-4}$ at the 90\% confidence level.
Phys. Rev. D 96, 052003 (2017) Using a data sample of $448\times10^{6}$ $\psi(3686)$ events collected with
the BESIII detector operating at the BEPCII storage ring, the decays
...$\psi(3686)\rightarrow\gamma\eta$ and $\psi(3686)\rightarrow\gamma\pi^{0}$ are
observed with a statistical significance of $7.3\sigma$ and $ 6.7\sigma$,
respectively. The branching fractions are measured to be
$\mathcal{B}(\psi(3686)\rightarrow\gamma\eta)=(0.85\pm0.18\pm0.05)\times10^{-6}$
and
$\mathcal{B}(\psi(3686)\rightarrow\gamma\pi^{0})=(0.95\pm0.16\pm0.05)\times10^{-6}$.
In addition, we measure the branching fraction of
$\psi(3686)\rightarrow\gamma\eta'$ to be
$\mathcal{B}(\psi(3686)\rightarrow\gamma\eta')=(125.1\pm2.2\pm6.2)\times
10^{-6}$, with improved precision compared to previous results.
Physics Letters B 774C (2017) pp. 78-86 Using data samples collected with the BESIII detector at the BEPCII collider
at six center-of-mass energies between 4.008 and 4.600 GeV, we observe the
...processes $e^+e^-\rightarrow \phi\phi\omega$ and $e^+e^-\rightarrow
\phi\phi\phi$. The Born cross sections are measured and the ratio of the cross
sections $\sigma(e^+e^-\rightarrow \phi\phi\omega)/\sigma(e^+e^-\rightarrow
\phi\phi\phi)$ is estimated to be $1.75\pm0.22\pm0.19$ averaged over six energy
points, where the first uncertainty is statistical and the second is
systematic. The results represent first measurements of these interactions.
Phys. Rev. Lett. 119, 072001 (2017) The spin and parity of the $Z_c(3900)^\pm$ state are determined to be
$J^P=1^+$ with a statistical significance larger than $7\sigma$ over other
quantum numbers in ...a partial wave analysis of the process $e^+e^-\to
\pi^+\pi^-J/\psi$. We use a data sample of 1.92 fb$^{-1}$ accumulated at
$\sqrt{s}=4.23$ and 4.26 GeV with the BESIII experiment. When parameterizing
the $Z_c(3900)^\pm$ with a Flatte-like formula, we determine its pole mass
$M_\textrm{pole}=(3881.2\pm4.2_\textrm{stat}\pm52.7_\textrm{syst})\textrm{MeV}/c^2$
and pole width
$\Gamma_\textrm{pole}=(51.8\pm4.6_\textrm{stat}\pm36.0_\textrm{syst})\textrm{MeV}$.
We also measure cross sections for the process $e^+e^-\to
Z_c(3900)^+\pi^-+c.c.\to J/\psi\pi^+\pi^-$ and determine an upper limit at the
90\% confidence level for the process $e^+e^-\to Z_c(4020)^+\pi^-+c.c.\to
J/\psi\pi^+\pi^-$.
Phys. Rev. D 96, 012001 (2017) We observe for the first time the process $e^{+}e^{-} \rightarrow \eta h_c$
with data collected by the BESIII experiment. Significant signals are observed
at the ...center-of-mass energy $\sqrt{s}=4.226$ GeV, and the Born cross section
is measured to be $(9.5^{+2.2}_{-2.0} \pm 2.7)$ pb. Evidence for $\eta h_c$ is
observed at $\sqrt{s}=4.358$ GeV with a Born cross section of
$(10.0^{+3.1}_{-2.7} \pm 2.6)$ pb, and upper limits on the production cross
section at other center-of-mass energies between 4.085 and 4.600 GeV are
determined.
Phys. Rev. D 92, 051101 (2015) Based on a sample of \etapr mesons produced in the radiative decay
$J/\psi\to\gamma\eta^{\prime}$ in $1.31\times 10^9$ $J/\psi$ events collected
with the BESIII ...detector, the decay $\eta^{\prime}\to\omega e^{+} e^{-}$ is
observed for the first time, with a statistical significance of $8\sigma$. The
branching fraction is measured to be $\mathcal{B}(\eta^{\prime}\to\omega e^{+}
e^{-})=(1.97\pm0.34(\text{stat})\pm0.17(\text{syst}))\times10^{-4}$, which is
in agreement with theoretical predictions. The branching fraction of
$\eta^{\prime}\to\omega\gamma$ is also measured to be
$(2.55\pm0.03(\text{stat})\pm0.16(\text{syst}))\times10^{-2}$, which is the
most precise measurement to date, and the relative branching fraction
$\frac{\mathcal{B}(\eta^{\prime}\to \omega
e^{+}e^{-})}{\mathcal{B}(\eta^{\prime}\to \omega \gamma)}$ is determined to be
$(7.71\pm1.34(\text{stat})\pm0.54(\text{syst}))\times10^{-3}$.
Phys. Rev. D 96, 012002 (2017) Using 2.93~fb$^{-1}$ of data taken at 3.773 GeV with the BESIII detector
operated at the BEPCII collider, we study the semileptonic decays $D^+ \to \bar
K^0e^+\nu_e$ ...and $D^+ \to \pi^0 e^+\nu_e$. We measure the absolute decay
branching fractions $\mathcal B(D^+ \to \bar K^0e^+\nu_e)=(8.60\pm0.06\pm
0.15)\times10^{-2}$ and $\mathcal B(D^+ \to
\pi^0e^+\nu_e)=(3.63\pm0.08\pm0.05)\times10^{-3}$, where the first
uncertainties are statistical and the second systematic. We also measure the
differential decay rates and study the form factors of these two decays. With
the values of $|V_{cs}|$ and $|V_{cd}|$ from Particle Data Group fits assuming
CKM unitarity, we obtain the values of the form factors at $q^2=0$, $f^K_+(0) =
0.725\pm0.004\pm 0.012$ and $f^{\pi}_+(0) = 0.622\pm0.012\pm 0.003$. Taking
input from recent lattice QCD calculations of these form factors, we determine
values of the CKM matrix elements $|V_{cs}|=0.944 \pm 0.005 \pm 0.015 \pm
0.024$ and $|V_{cd}|=0.210 \pm 0.004 \pm 0.001 \pm 0.009$, where the third
uncertainties are theoretical.
Phys. Rev. D 96, 032004 (2017) We study the process $e^{+}e^{-} \rightarrow \pi^{+}\pi^{-}\psi(3686)$ using
5.1 $fb^{-1}$ of data collected at 16 center-of-mass energy ($\sqrt{s}$) points
from 4.008 ...to 4.600$\sim$GeV by the BESIII detector operating at the BEPCII
collider. The measured Born cross sections for $e^{+}e^{-}\rightarrow
\pi^{+}\pi^{-}\psi(3686)$ are consistent with previous results, but with much
improved precision. A fit to the cross section shows contributions from two
structures: the first has $M=4209.5\pm7.4\pm1.4$$\sim$MeV/$c^{2}$ and
$\Gamma=80.1\pm24.6\pm2.9$$\sim$MeV, and the second has
$M=4383.8\pm4.2\pm0.8$$\sim$MeV/c$^{2}$ and
$\Gamma=84.2\pm12.5\pm2.1$$\sim$MeV, where the first errors are statistical and
the second systematic. The lower-mass resonance is observed in the process
$e^{+}e^{-}\rightarrow \pi^{+}\pi^{-}\psi(3686)$ for the first time with a
statistical significance of $5.8\sigma$. A charged charmonium-like structure is
observed in the $\pi^{\pm}\psi(3686)$ invariant mass spectrum for data at
$\sqrt{s} = 4.416~$GeV. A fit with an $S$-wave Breit-Wigner function yields a
mass $M=4032.1\pm2.4$~$MeV$^{2}$, where the errors are statistical only.
However, there are still unresolved discrepancies between the fit model and
data. The width of the intermediate state varies in a wide range for different
kinematic regions within the data set. Therefore no simple interpretation of
the data has been found, and a future data sample with larger statistics and
more theoretical input will be required to better understand this issue.
Phys. Rev. Lett. 115, 182002 (2015) We report a study of the process $e^{+} e^{-} \to (D^{*} \bar{D}^{*})^{0}
\pi^0$ using $e^+e^-$ collision data samples with integrated luminosities of
$1092 ...\rm{pb}^{-1}$ at $\sqrt{s}=4.23 \rm{GeV}$ and $826 \rm{pb}^{-1}$ at
$\sqrt{s}=4.26 \rm{GeV}$ collected with the BESIII detector at the BEPCII
storage ring. We observe a new neutral structure near the $(D^{*}
\bar{D}^{*})^{0}$ mass threshold in the $\pi^0$ recoil mass spectrum, which we
denote as $Z_{c}(4025)^{0}$. Assuming a Breit-Wigner line shape, its pole mass
and pole width are determined to be $(4025.5^{+2.0}_{-4.7}\pm3.1) \rm{MeV}/c^2$
and $(23.0\pm 6.0\pm 1.0) \rm{MeV}$, respectively. The Born cross sections of
$e^{+}e^{-}\to Z_{c}(4025)^{0} \pi^0\to (D^{*} \bar{D}^{*})^{0}\pi^0$ are
measured to be $(61.6\pm8.2\pm9.0) \rm{pb}$ at $\sqrt{s}=4.23 \rm{GeV}$ and
$(43.4\pm8.0\pm5.4) \rm{pb}$ at $\sqrt{s}=4.26 \rm{GeV}$. The first
uncertainties are statistical and the second are systematic.
