Publications (895)2912.36 Total impact
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ABSTRACT: We report a study of the process $e^{+} e^{} \to (D^{*} \bar{D}^{*})^{0} \pi^0$ using $e^+e^$ collision data samples with integrated luminosity 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 BreitWigner 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 statistical significance of the observation is $7.4\sigma$. 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.  [Show abstract] [Hide abstract]
ABSTRACT: The decay $Z_c(3900)^\pm\to\omega\pi^\pm$ is searched for using data samples collected with the BESIII detector operating at the BEPCII storage ring at centerofmass energies $\sqrt{s}=4.23$ and $4.26$~GeV. No significant signal for the $Z_c(3900)^\pm$ is found, and upper limits at the 90\% confidence level on the Born cross section for the process $e^+e^\to Z_c(3900)^\pm\pi^\mp\to\omega\pi^+\pi^$ are determined to be $0.26$ and $0.18$ pb at $\sqrt{s}=4.23$ and 4.26 GeV, respectively.  [Show abstract] [Hide abstract]
ABSTRACT: 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 $\mathcal{B}(D^+_{s}\rightarrow \eta'X)$ = (8.8$\pm$1.8$\pm$0.5)\% and $\mathcal{B}(D_{s}^{+}\rightarrow \eta'\rho^{+})$ = ($5.8\pm1.4\pm0.4$)\% where the first uncertainty is statistical and the second is systematic. In addition, we estimate an upper limit on the nonresonant branching ratio $\mathcal{B}(D_{s}^{+}\rightarrow \eta'\pi^+\pi^0)<5.1\%$ at the 90\% confidence level. Our results are consistent with CLEO's recent measurements and help to resolve the disagreement between the theoretical prediction and CLEO's previous measurement of $\mathcal{B}(D_{s}^{+}\rightarrow \eta'\rho^{+})$.  [Show abstract] [Hide abstract]
ABSTRACT: Based on a sample of $1.31 \times 10^9$ $J/\psi$ events collected with the BESIII detector at the BEPCII collider, Dalitz plot analyses of selected 79,625 $\eta\rightarrow\pi^{+}\pi^{}\pi^0$ events, 33,908 $\eta\rightarrow\pi^0\pi^0\pi^0$ events and 1,888 $\eta^{\prime}\rightarrow\pi^0\pi^0\pi^0$ events are performed. The measured matrix elements of $\eta\rightarrow\pi^+\pi^\pi^0$ are in reasonable agreement with previous measurements. The Dalitz plot slope parameters of $\eta\rightarrow\pi^0\pi^0\pi^0$ and $\eta^{\prime}\rightarrow\pi^0\pi^0\pi^0$ are determined to be $0.055 \pm 0.014 \pm 0.004$ and $0.640 \pm 0.046 \pm 0.047$, respectively, where the first uncertainties are statistical and the second systematic. Both values are consistent with previous measurements, while the precision of the latter one is improved by a factor of three. Final state interactions are found to have an important role in those decays.  [Show abstract] [Hide abstract]
ABSTRACT: We report an observation of the process $J/\psi\rightarrow\gamma X(1835)\rightarrow\gamma K^0_S K^0_S\eta$ at low $K^0_S K^0_S$ mass with a statistical significance larger than 12.9$\sigma$ using a data sample of $1.31 \times 10^{9}$ $J/\psi$ events collected with the BESIII detector. In this region of phase space the $K^0_S K^0_S$ system is dominantly produced through the $f_0(980)$. By performing a partial wave analysis, we determine the spinparity of the $X(1835)$ to be $J^{PC}=0^{+}$. The mass and width of the observed $X(1835)$ are $1844\pm9(\text{stat})^{+16}_{25}(\text{syst})$~\MeV~and $192^{+20}_{17}(\text{stat})^{+62}_{43}(\text{syst})$~MeV, respectively, which are consistent with the results obtained by BESIII in the channel $J/\psi\rightarrow\gamma\pi^+\pi^\eta^{\prime}$.  [Show abstract] [Hide abstract]
ABSTRACT: An amplitude analysis of the $\pi^{0}\pi^{0}$ system produced in radiative $J/\psi$ decays is presented. In particular, a piecewise function that describes the dynamics of the $\pi^{0}\pi^{0}$ system is determined as a function of $M_{\pi^{0}\pi^{0}}$ from an analysis of the $(1.311\pm0.011)\times10^{9}$ $J/\psi$ decays collected by the BESIII detector. The goal of this analysis is to provide a description of the scalar and tensor components of the $\pi^0\pi^0$ system while making minimal assumptions about the properties or number of poles in the amplitude. Such a modelindependent description allows one to integrate these results with other related results from complementary reactions in the development of phenomenological models, which can then be used to directly fit experimental data to obtain parameters of interest. The branching fraction of $J/\psi \to \gamma \pi^{0}\pi^{0}$ is determined to be $(1.15\pm0.05)\times10^{3}$, where the uncertainty is systematic only and the statistical uncertainty is negligible.  [Show abstract] [Hide abstract]
ABSTRACT: Using a sample of 1.31 billion $J/\psi$ events collected with the BESIII detector at the BEPCII collider, the decays $J/\psi \to \phi \pi^{+}\pi^{}\pi^{0}$ and $J/\psi \to \phi \pi^{0}\pi^{0}\pi^{0}$ are investigated. The isospin violating decay $J/\psi \to \phi \pi^{0} f_{0}(980)$ with $f_{0}(980) \to \pi\pi$, is observed for the first time. The width of the $f_{0}(980)$ obtained from the dipion mass spectrum is found to be much smaller than the world average value. In the $\pi^{0} f_{0}(980)$ mass spectrum, there is evidence of $f_1(1285)$ production. By studying the decay $J/\psi \to \phi\eta'$, the branching fractions of $\eta' \to \pi^{+}\pi^{}\pi^{0}$ and $\eta' \to \pi^{0}\pi^{0}\pi^{0}$, as well as their ratio, are also measured.  [Show abstract] [Hide abstract]
ABSTRACT: Using $2.92$ fb$^{1}$ of electronpositron annihilation data collected at $\sqrt{s} = 3.773$~GeV with the BESIII detector, we report the results of a search for the flavorchanging neutral current process $D^0\to\gamma\gamma$ using a doubletag technique. We find no signal and set an upper limit at $90\%$ confidence level for the branching fraction of $B(D^0\to\gamma\gamma) < 3.8\times10^{6}$. We also investigate $D^0$meson decay into two neutral pions, obtaining a branching fraction of $B(D^0\to\pi^0\pi^0) = (8.24\pm0.21(\text{stat.})\pm0.30(\text{syst.}))\times10^{4}$, the most precise measurement to date and consistent with the current world average  [Show abstract] [Hide abstract]
ABSTRACT: Using the data sets taken at centerofmass energies above 4 GeV by the BESIII detector at the BEPCII storage ring, we search for the reaction e+e > gamma_ISR X(3872) > gamma_ISR pi+piJ/psi via the Initial State Radiation technique. The production of a resonance with quantum numbers J^PC = 1^++ such as the X(3872) via single photon e+e annihilation is forbidden, but is allowed by a nexttoleading order box diagram. We do not observe a significant signal of X(3872), and therefore give an upper limit for the electronic width times the branching fraction Gamma_ee^X(3872)Br(X(3872) > pi+piJ\psi) < 0.13 eV at the 90% confidence level. This measurement improves upon existing limits by a factor of 46. Using the same final state, we also measure the electronic width of the psi(3686) to be Gamma_ee^psi(3686) = 2231 + 18 + 99 eV.  [Show abstract] [Hide abstract]
ABSTRACT: Using data samples collected at center of mass energies of $\sqrt{s}$ = 4.009, 4.226, 4.257, 4.358, 4.416 and 4.599 GeV with the BESIII detector operating at the BEPCII storage ring, we search for the isospin violating decay $Y(4260)\rightarrow J/\psi \eta \pi^{0}$. No signal is observed, and upper limits on the cross section $\sigma(e^{+}e^{}\rightarrow J/\psi \eta \pi^{0})$ at the 90\% confidence level are determined to be 3.6, 1.7, 2.4, 1.4, 0.9 and 1.9 pb, respectively.  [Show abstract] [Hide abstract]
ABSTRACT: We present a search for a neutral, longlived particle L that is produced in e^{+}e^{} collisions and decays at a significant distance from the e^{+}e^{} interaction point into various flavor combinations of two oppositely charged tracks. The analysis uses an e^{+}e^{} data sample with a luminosity of 489.1 fb^{1} collected by the BABAR detector at the ϒ(4S), ϒ(3S), and ϒ(2S) resonances and just below the ϒ(4S). Fitting the twotrack mass distribution in search of a signal peak, we do not observe a significant signal, and set 90% confidence level upper limits on the product of the L production cross section, branching fraction, and reconstruction efficiency for six possible twobody L decay modes as a function of the L mass. The efficiency is given for each final state as a function of the mass, lifetime, and transverse momentum of the candidate, allowing application of the upper limits to any production model. In addition, upper limits are provided on the branching fraction B(B→X_{s}L), where X_{s} is a strange hadronic system.Physical Review Letters 05/2015; 114(17):171801. · 7.51 Impact Factor  [Show abstract] [Hide abstract]
ABSTRACT: We present a search for a neutral, longlived particle L that is produced in e[superscript +]e[superscript ] collisions and decays at a significant distance from the e[superscript +]e[superscript ] interaction point into various flavor combinations of two oppositely charged tracks. The analysis uses an e[superscript +]e[superscript ] data sample with a luminosity of 489.1 fb[superscript 1] collected by the BABAR detector at the ϒ(4S), ϒ(3S), and ϒ(2S) resonances and just below the ϒ(4S). Fitting the twotrack mass distribution in search of a signal peak, we do not observe a significant signal, and set 90% confidence level upper limits on the product of the L production cross section, branching fraction, and reconstruction efficiency for six possible twobody L decay modes as a function of the L mass. The efficiency is given for each final state as a function of the mass, lifetime, and transverse momentum of the candidate, allowing application of the upper limits to any production model. In addition, upper limits are provided on the branching fraction B(B → X[subscript s]L), where X[subscript s] is a strange hadronic system.  [Show abstract] [Hide abstract]
ABSTRACT: We report a measurement of the branching fraction of $\psi(3770)\to\gamma\chi_{c1}$ and search for the transition $\psi(3770)\rightarrow \gamma \chi_{c2}$ based on 2.92~fb$^{1}$ of $e^+e^$ data accumulated at $\sqrt{s}=3.773$~GeV with the BESIII detector at the BEPCII collider. The measured branching fraction of $\psi(3770) \rightarrow \gamma \chi_{c1}$ is $\mathcal B(\psi(3770) \rightarrow \gamma \chi_{c1})=(2.48 \pm 0.15 \pm 0.23) \times 10^{3}$, which is the most precise measurement to date. The upper limit on the branching fraction of $\psi(3770)\rightarrow \gamma \chi_{c2}$ at a $90\%$ confidence level is $\mathcal B(\psi(3770) \rightarrow \gamma \chi_{c2})<0.64 \times 10^{3}$. The corresponding partial widths are $\Gamma(\psi(3770) \to \gamma \chi_{c1}) =(67.5\pm 4.1\pm 6.7)$~keV and $\Gamma(\psi(3770) \to \gamma \chi_{c2}) < 17.4$~keV.  [Show abstract] [Hide abstract]
ABSTRACT: 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 $\Gamma(\eta' \to \gamma e^+ e^)/\Gamma(\eta'\to\gamma\gamma)$ is measured to be $(2.13\pm0.09(\text{stat.})\pm0.07(\text{sys.}))\times10^{2}$. 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.  [Show abstract] [Hide abstract]
ABSTRACT: Using data samples collected with the BESIII detector at the BEPCII collider, we measure the Born cross section of $e^{+}e^{}\rightarrow p\bar{p}$ at 12 centerofmass energies from 2232.4 to 3671.0 MeV. The corresponding effective electromagnetic form factor of the proton is deduced under the assumption that the electric and magnetic form factors are equal $(G_{E}= G_{M})$. In addition, the ratio of electric to magnetic form factors, $G_{E}/G_{M}$, and $G_{M}$ are extracted by fitting the polar angle distribution of the proton for the data samples with larger statistics, namely at $\sqrt{s}=$ 2232.4 and 2400.0 MeV and a combined sample at $\sqrt{s}$ = 3050.0, 3060.0 and 3080.0 MeV, respectively. The measured cross sections are in agreement with recent results from BaBar, improving the overall uncertainty by about 30\%. The $G_{E}/G_{M}$ ratios are close to unity and consistent with BaBar results in the same $q^{2}$ region, which indicates the data are consistent with the assumption that $G_{E}=G_{M}$ within uncertainties. 
Article: Observation of the electromagnetic doubly OZIsuppressed decay $J/\psi \rightarrow \phi \pi^{0}$
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ABSTRACT: Using a sample of $1.31$ billion $J/\psi$ events accumulated with the BESIII detector at the BEPCII collider, we report the observation of the decay $J/\psi \rightarrow \phi\pi^{0}$, which is the first evidence for a doubly OkuboZweigIizuka suppressed electromagnetic $J/\psi$ decay. A clear structure is observed in the $K^{+} K^{}$ mass spectrum around 1.02 GeV/$c^2$, which can be attributed to interference between $J/\psi \rightarrow \phi\pi^{0}$ and $J/\psi \rightarrow K^{+}K^{}\pi^{0}$ decays. Due to this interference, two possible solutions are found. The corresponding measured values of the branching fraction of $J/\psi \to \phi\pi^{0}$ are $[2.94 \pm 0.16\text{(stat.)} \pm 0.16\text{(syst.)}] \times 10^{6}$ and $[1.24 \pm 0.33\text{(stat.)} \pm 0.30\text{(syst.)}] \times 10^{7}$.  [Show abstract] [Hide abstract]
ABSTRACT: Using a sample of $1.06\times10^8\ \psip$ events produced in $e^+e^$ collisions at $\sqrt{s}$ = 3.686 GeV and collected with the BESIII detector at the BEPCII collider, we present studies of the decays $\klx+c.c.$ and $\gklx+c.c.$. We observe two hyperons, $\Xi(1690)^$ and $\Xi(1820)^$, in the $K^\Lambda$ invariant mass distribution in the decay $\klx+c.c.$ with significances of $4.9 \sigma$ and $6.2 \sigma$, respectively. The branching fractions of $\klx+c.c.$, $\ksx+c.c.$, $\psip\to\gamma \chi_{cJ}\to \gamma K^ \Lambda \bar{\Xi}^+ +c.c.$ $(J=0,\ 1,\ 2)$, and $\psip\to \Xi(1690/1820)^{} \bar{\Xi}^++c.c$ with subsequent decay $\Xi(1690/1820)^\to K^\Lambda$ are measured for the first time.  [Show abstract] [Hide abstract]
ABSTRACT: Based on a sample of 500 million e[superscript +]e[superscript ] → c[bar over c] events recorded by the BABAR detector at c.m. energies of close to 10.6 GeV, we report on a study of the decay D[superscript 0] → π[superscript ]e[superscript +]ν[subscript e]. We measure the ratio of branching fractions, R[subscript D] = B(D[superscript 0] → π[superscript ]e[superscript +]ν[subscript e])/B(D[superscript 0] → K[superscript ]π[superscript +]) = 0.0713 ± 0.0017[subscript stat] ± 0.0024[subscript syst], and use the present world average for B(D[superscript 0] → K[superscript ]π[superscript +] to obtain B(D[superscript 0] → π[superscript ]e[superscript +]ν[subscript e]) = (2.770 ± 0.068[subscript stat] ± 0.092[subscript syst] ± 0.037[subscript ext]) × 10[superscript 3] where the third error accounts for the uncertainty on the branching fraction for the reference channel. The measured dependence of the differential branching fraction on q[superscript 2], the fourmomentum transfer squared between the D and the π meson, is compared to various theoretical predictions for the hadronic form factor, f[π over +,D](q[superscript 2]), and the normalization V[subscript cd] × f[π over +,D](q[superscript 2] = 0) = 0.1374 ± 0.0038[subscript stat] ± 0.0022[subscript syst] ± 0.0009[subscript ext] is extracted from a fit to data. Using the most recent LQCD prediction of f[π over +,D](q[superscript 2] = 0) = 0.666 ± 0.029, we obtain V[subscript cd] = 0.206 ± 0.007[subscript exp] ± 0.009[subscript LQCD]. Assuming, instead, V[subscript cd] = V[subscript us] = 0.2252 ± 0.0009, we obtain f[π over +,D](q[superscript 2] = 0) = 0.610 ± 0.020subscript exp] ± 0.005[subscript ext]. The q[superscript 2] dependence of f[π over +,D](q[superscript 2]) is compared to a variety of multipole parametrizations. This information is applied to B[superscript 0] → π[superscript ]e[superscript +]ν[subscript e] decays and, combined with an earlier B[superscript 0] → π[superscript ]e[superscript +]ν[subscript e] measurement by BABAR, is used to derive estimates of V[subscript ub].  [Show abstract] [Hide abstract]
ABSTRACT: We report the observation of the $X(3823)$ in the process $e^+e^\to \pi^+\pi^X(3823) \to \pi^+\pi^\gamma\chi_{c1}$ with a statistical significance of $6.2\sigma$, in data samples at centerofmass energies $\sqrt{s}=$4.230, 4.260, 4.360, 4.420 and 4.600~GeV collected with the BESIII detector at the BEPCII electron positron collider. The measured mass of the $X(3823)$ is $(3821.7\pm 1.3\pm 0.7)$~MeV/$c^2$, where the first error is statistical and the second systematic, and the width is less than $16$~MeV at the 90\% confidence level. The products of the Born cross sections for $e^+e^\to \pi^+\pi^X(3823)$ and the branching ratio $\mathcal{B}[X(3823)\to \gamma\chi_{c1,c2}]$ are also measured. These measurements are in good agreement with the assignment of the $X(3823)$ as the $\psi(1^3D_2)$ charmonium state.  [Show abstract] [Hide abstract]
ABSTRACT: Using data samples collected with the BESIII detector operating at the BEPCII collider at centerofmass 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 energydependent 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.
Publication Stats
3k  Citations  
2,912.36  Total Impact Points  
Top Journals
 Physical Review D (221)
 Physical Review Letters (152)
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Institutions

2014–2015

University of Ferrara
Ferrare, EmiliaRomagna, Italy


2004–2015

Università degli Studi di Perugia
 Department of Physics
Perugia, Umbria, Italy


2011

Institute of physics china
Peping, Beijing, China


2010

Government of the People's Republic of China
Peping, Beijing, China


2006–2010

INFN  Istituto Nazionale di Fisica Nucleare
Frascati, Latium, Italy


2008–2009

Centro FERMI
Roma, Latium, Italy 
University of Surrey
Guilford, England, United Kingdom


2006–2009

Université de Savoie
Chambéry, RhôneAlpes, France


2005–2007

University of Milan
Milano, Lombardy, Italy 
RuhrUniversität Bochum
 Institut für Experimentalphysik I
Bochum, North RhineWestphalia, Germany 
University of California, Davis
Davis, California, United States
