Y. Ban

We report the first observation of a narrow charmmonium state produced in the exclusive decay process B+->K+ pi+pi- J/psi. This state, which decays into pi+pi-J/psi, has a mass of 3871.8+-0.7(stat)+-0.4(syst) MeV, which is very near the M_D + M_D* mass threshold. The results are based on an analysis of 152M BBbar events collected at the Upsilon(4S) resonance in the Belle detector at the KEKB collider.

We study the process ee+ e- → π+ π- J/ψ at a center-of-mass energy of 4.260 GeV using a 525 pb(-1) data sample collected with the BESIII detector operating at the Beijing Electron Positron Collider. The Born cross section is measured to be (62.9±1.9±3.7) pb, consistent with the production of the Y(4260). We observe a structure at around 3.9 GeV/c2 in the π(±)J/ψ mass spectrum, which we refer to as the Z(c)(3900). If interpreted as a new particle, it is unusual in that it carries an electric charge and couples to charmonium. A fit to the π(±)J/ψ invariant mass spectrum, neglecting interference, results in a mass of (3899.0±3.6±4.9) MeV/c2 and a width of (46±10±20) MeV. Its production ratio is measured to be R = (σ(e+ e- → π(±)Z(c)(3900)(∓) → π+ π- J/ψ)/σ(e+ e- → π+ π- J/ψ)) = (21.5±3.3±7.5)%. In all measurements the first errors are statistical and the second are systematic.

We study e+e-→π+π-hc at center-of-mass energies from 3.90 to 4.42 GeV by using data samples collected with the BESIII detector operating at the Beijing Electron Positron Collider. The Born cross sections are measured at 13 energies and are found to be of the same order of magnitude as those of e+e-→π+π-J/ψ but with a different line shape. In the π±hc mass spectrum, a distinct structure, referred to as Zc(4020), is observed at 4.02 GeV/c2. The Zc(4020) carries an electric charge and couples to charmonium. A fit to the π±hc invariant mass spectrum, neglecting possible interferences, results in a mass of (4022.9±0.8±2.7) MeV/c2 and a width of (7.9±2.7±2.6) MeV for the Zc(4020), where the first errors are statistical and the second systematic. The difference between the parameters of this structure and the Zc(4025) observed in the D*D[over ¯]* final state is within 1.5σ, but whether they are the same state needs further investigation. No significant Zc(3900) signal is observed, and upper limits on the Zc(3900) production cross sections in π±hc at center-of-mass energies of 4.23 and 4.26 GeV are set.

We report the observation of a near-threshold enhancement in the omegaJ/psi invariant mass distribution for exclusive B-->KomegaJ/psi decays. The results are obtained from a 253 fb(-1) data sample that contains 275 x 10(6) BB pairs that were collected near the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric energy e(+)e(-) collider. The statistical significance of the omegaJ/psi mass enhancement is estimated to be greater than 8sigma.

We report on a study of the process e+ e- → π± (DD*)∓ at sqrt[s] = 4.26 GeV using a 525 pb(-1) data sample collected with the BESIII detector at the BEPCII storage ring. A distinct charged structure is observed in the (DD*)∓ invariant mass distribution. When fitted to a mass-dependent-width Breit-Wigner line shape, the pole mass and width are determined to be Mpole = (3883.9±1.5(stat)±4.2(syst)) MeV/c2 and Γpole = (24.8±3.3(stat)±11.0(syst)) MeV. The mass and width of the structure, which we refer to as Zc(3885), are 2σ and 1σ, respectively, below those of the Zc(3900) → π± J/ψ peak observed by BESIII and Belle in π+ π- J/ψ final states produced at the same center-of-mass energy. The angular distribution of the πZc(3885) system favors a JP = 1+ quantum number assignment for the structure and disfavors 1- or 0-. The Born cross section times the DD* branching fraction of the Zc(3885) is measured to be σ(e+ e- → π± Zc(3885)∓)×B(Zc(3885)∓ → (DD*)∓) = (83.5±6.6(stat)±22.0(syst)) pb. Assuming the Zc(3885) → DD* signal reported here and the Zc(3900) → πJ/ψ signal are from the same source, the partial width ratio (Γ(Zc(3885) → DD*)/Γ(Zc(3900) → πJ/ψ)) = 6.2±1.1(stat)±2.7(syst) is determined.

We study the process e+e−→(D∗¯D∗)±π∓ at a center-of-mass energy of 4.26 GeV using a 827 pb−1 data sample obtained with the BESIII detector at the Beijing Electron Positron Collider. Based on a partial reconstruction technique, the Born cross section is measured to be (137±9±15) pb. We observe a structure near the (D∗¯D∗)± threshold in the π∓ recoil mass spectrum, which we denote as the Z±c(4025). The measured mass and width of the structure are (4026.3±2.6±3.7) MeV/c2 and (24.8±5.6±7.7) MeV, respectively. Its production ratio σ(e+e−→Z±c(4025)π∓→(D∗¯D∗)±π∓)/σ(e+e−→(D∗¯D∗)±π∓) is determined to be 0.65±0.09±0.06. The first uncertainties are statistical and the second are systematic.Received 13 August 2013DOI:https://doi.org/10.1103/PhysRevLett.112.132001© 2014 American Physical Society

The Belle detector at the KEKB electron-positron collider has collected almost 1 billion Y(4S) events in its decade of operation. Super-KEKB, an upgrade of KEKB is under construction, to increase the luminosity by two orders of magnitude during a three-year shutdown, with an ultimate goal of 8E35 /cm^2 /s luminosity. To exploit the increased luminosity, an upgrade of the Belle detector has been proposed. A new international collaboration Belle-II, is being formed. The Technical Design Report presents physics motivation, basic methods of the accelerator upgrade, as well as key improvements of the detector.

The cross section for the process $e^+e^-\to \pi^+\pi^-J/\psi$ is measured precisely at center-of-mass energies from 3.77 to 4.60~GeV using 9~fb$^{-1}$ of data collected with the BESIII detector operating at the BEPCII storage ring. Two resonant structures are observed in a fit to the cross section. The first resonance has a mass of $(4222.0\pm 3.1\pm 1.4)$~MeV/$c^2$ and a width of $(44.1\pm 4.3\pm 2.0)$~MeV, while the second one has a mass of $(4320.0\pm 10.4 \pm 7.0)$~MeV/$c^2$ and a width of $(101.4^{+25.3}_{-19.7}\pm 10.2)$~MeV, where the first errors are statistical and second ones are systematic. The first resonance agrees with the $Y(4260)$ resonance reported by previous experiments. The precision of its resonant parameters is improved significantly. The second resonance is observed in $e^+e^-\to \pi^+\pi^-J/\psi$ for the first time. The statistical significance of this resonance is estimated to be larger than $7.6\sigma$. The mass and width of the second resonance agree with the $Y(4360)$ resonance reported by the $BABAR$ and Belle experiments within errors. Finally, the $Y(4008)$ resonance previously observed by the Belle experiment is not confirmed in the description of the BESIII data.

The cross sections of ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}{h}_{c}$ at center-of-mass energies from 3.896 to 4.600 GeV are measured using data samples collected with the BESIII detector operating at the Beijing Electron Positron Collider. The cross sections are found to be of the same order of magnitude as those of ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}J/\ensuremath{\psi}$ and ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}\ensuremath{\psi}(2S)$, but the line shape is inconsistent with the $Y$ states observed in the latter two modes. Two structures are observed in the ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}{h}_{c}$ cross sections around 4.22 and $4.39\text{ }\text{ }\mathrm{GeV}/{c}^{2}$, which we call $Y(4220)$ and $Y(4390)$, respectively. A fit with a coherent sum of two Breit-Wigner functions results in a mass of $(4218.{4}_{\ensuremath{-}4.5}^{+5.5}\ifmmode\pm\else\textpm\fi{}0.9)\text{ }\text{ }\mathrm{MeV}/{c}^{2}$ and a width of $(66.{0}_{\ensuremath{-}8.3}^{+12.3}\ifmmode\pm\else\textpm\fi{}0.4)\text{ }\text{ }\mathrm{MeV}$ for the $Y(4220)$, and a mass of $(4391.{5}_{\ensuremath{-}6.8}^{+6.3}\ifmmode\pm\else\textpm\fi{}1.0)\text{ }\text{ }\mathrm{MeV}/{c}^{2}$ and a width of $(139.{5}_{\ensuremath{-}20.6}^{+16.2}\ifmmode\pm\else\textpm\fi{}0.6)\text{ }\text{ }\mathrm{MeV}$ for the $Y(4390)$, where the first uncertainties are statistical and the second ones systematic. The statistical significance of $Y(4220)$ and $Y(4390)$ is $10\ensuremath{\sigma}$ over one structure assumption.

We report a study of the processes of e+e−→K+D−sD*0 and K+D*−sD0 based on e+e− annihilation samples collected with the BESIII detector operating at BEPCII at five center-of-mass energies ranging from 4.628 to 4.698 GeV with a total integrated luminosity of 3.7 fb−1. An excess of events over the known contributions of the conventional charmed mesons is observed near the D−sD*0 and D*−sD0 mass thresholds in the K+ recoil-mass spectrum for events collected at √s=4.681 GeV. The structure matches a mass-dependent-width Breit-Wigner line shape, whose pole mass and width are determined as (3982.5+1.8−2.6±2.1) MeV/c2 and (12.8+5.3−4.4±3.0) MeV, respectively. The first uncertainties are statistical and the second are systematic. The significance of the resonance hypothesis is estimated to be 5.3 σ over the contributions only from the conventional charmed mesons. This is the first candidate for a charged hidden-charm tetraquark with strangeness, decaying into D−sD*0 and D*−sD0. However, the properties of the excess need further exploration with more statistics.Received 16 November 2020Accepted 5 February 2021DOI:https://doi.org/10.1103/PhysRevLett.126.102001Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP3.Published by the American Physical SocietyPhysics Subject Headings (PhySH)Research AreasLepton-lepton interactionsQuark modelParticles & Fields

We observe a narrow enhancement near 2m(p) in the invariant mass spectrum of pp pairs from radiative J/psi-->gammapp decays. No similar structure is seen in J/psi-->pi(0)pp decays. The results are based on an analysis of a 58 x 10(6) event sample of J/psi decays accumulated with the BESII detector at the Beijing electron-positron collider. The enhancement can be fit with either an S- or P-wave Breit-Wigner resonance function. In the case of the S-wave fit, the peak mass is below 2m(p) at M=1859(+3)(-10) (stat)+5-25(syst) MeV/c(2) and the total width is Gamma<30 MeV/c(2) at the 90% confidence level. These mass and width values are not consistent with the properties of any known particle.

We report the observation of prompt J/psi via double cc; production from the e+e- continuum. In this process one cc; pair fragments into a J/psi meson while the remaining pair either produces a charmonium state or fragments into open charm. Both cases have been experimentally observed. We find cross sections of sigma[e+e- -->J/psieta(c)(gamma)]xB(eta(c)-->>or=4 charged)=(0.033(+0.007)(-0.006)+/-0.009) pb and sigma(e+e- -->J/psiD(*+)X)=(0.53(+0.19)(-0.15)+/-0.14) pb and infer sigma(e+e- -->J/psicc;)/sigma(e+e- -->J/psiX)=0.59(+0.15)(-0.13)+/-0.12. These results are obtained from a 46.2 fb(-1) data sample collected near the Upsilon(4S) resonance, with the Belle detector at the KEKB collider.

A partial wave analysis is presented of J/ψ→ϕπ+π− and ϕK+K− from a sample of 58M J/ψ events in the BES II detector. The f0(980) is observed clearly in both sets of data, and parameters of the Flatté formula are determined accurately: M=965±8(stat)±6(syst)MeV/c2, g1=165±10±15MeV/c2, g2/g1=4.21±0.25±0.21. The ϕππ data also exhibit a strong ππ peak centred at M=1335MeV/c2. It may be fitted with f2(1270) and a dominant 0+ signal made from f0(1370) interfering with a smaller f0(1500) component. There is evidence that the f0(1370) signal is resonant, from interference with f2(1270). There is also a state in ππ with M=1790−30+40MeV/c2 and Γ=270−30+60MeV/c2; spin 0 is preferred over spin 2. This state, f0(1790), is distinct from f0(1710). The ϕKK¯ data contain a strong peak due to f2′(1525). A shoulder on its upper side may be fitted by interference between f0(1500) and f0(1710).

We report the results of a study of charged B decays to the D+- pi-+ pi-+ and D*+- pi-+ pi-+ final states using complete D(*) reconstruction. The contributions of two-body B => D** pi decays with narrow (j=3/2) and broad (j=1/2) D** states have been determined and the masses and widths of four D** states have been measured. This is the first observation of the broad D*0_0 and D'0_1 mesons. The analysis is based on a data sample of 65 million B barB pairs collected in the Belle experiment.

We report values of R = sigma(e(+)e(-)-->hadrons)/sigma(e(+)e(-)-->mu(+)mu(-)) for 85 center-of-mass energies between 2 and 5 GeV measured with the upgraded Beijing Spectrometer at the Beijing Electron-Positron Collider.

We report a fully inclusive measurement of the flavor changing neutral current decay b --> sgamma in the energy range 1.8 GeV < or = E*gamma < or = 2.8 GeV, covering 95% of the total spectrum. Using 140 fb(-1), we obtain B(b --> sgamma) = (3.55+/-0.32(+0.30+0.11)(-0.31-0.07)) x 10(-4), where the errors are statistical, systematic, and from theory corrections. We also measure the first and second moments of the photon energy spectrum above 1.8 GeV and obtain (Egamma) = 2.292+/-0.026+/-0.034 GeV and (E2gamma) - (Egamma)2 = 0.0305+/-0.0074+/-0.0063 GeV2, where the errors are statistical and systematic.

A new measurement of the proton structure function F2 (x, Q2) is reported for momentum transfers squared Q2 between ].5 GeV2 and 5000 GeV2 and for Bjorken x between 3 · 10−5 and 0.32 using data collected by the HERA experiment H1 in 1994. The data represent an increase in statistics by a factor of ten with respect to the analysis of the 1993 data. Substantial extension of the kinematic range towards low Q2 and x has been achieved using dedicated data samples and events with initial state photon radiation. The structure function is found to increase significantly with decreasing x, even in the lowest accessible Q2 region. The data are well described by a Next to Leading Order QCD fit and the gluon density is extracted.

The decay channel J/psi --> gamma(pi)(+)pi(-)eta is analyzed using a sample of 5.8 x 10(7) J/psi events collected with the BESII detector. A resonance, the Chi(1835), is observed in the pi(+)pi(-)eta invariant-mass spectrum with a statistical significance of 7.7 sigma. A fit with a Breit-Wigner function yields a mass M = 1833.7 +/- 6.1(stat) +/- 2.7(syst) MeV/c(2), a width Tau = 67.7 +/- 20.3(stat) +/- 7.7(syst) MeV/c(2), and a product branching fraction B(J/psi --> gammaChi) . B(Chi --> pi(+)pi(-)eta) = [2.2 +/- 0.4(stat) +/- 0.4(syst)] x 10(-4). The mass and width of the Chi(1835) are not compatible with any known meson resonance. Its properties are consistent with expectations for the state that produces the strong pp mass threshold enhancement observed in the J/psi --> gammapp process at BESII.

ABSTRACTABSTRACTAs a strategic factor for a country to survive in the global competition, transportation systems have attracted extensive attention from different disciplines for a long time. Since the introduction of complex network theory in the last decade, however, studies on transport systems have witnessed dramatic progress. Most roads, streets, and rails are organized as a network pattern, while link flows, travel time, or geographical distance are regarded as weights. In this article, the authors will present the current state of topological research on transportation systems under a complex network framework, as well as the efforts and challenges that have been made in the last decade. First, different kinds of transportation systems should be generalized as networks in different ways, which will be explained in the first part of this paper. We follow this by summarizing network measures that describe topological characteristics of transportation networks. Then we discuss the empirical observations from the last decade on real transportation systems at a variety of spatial scales. This paper concludes with some important challenges and open research frontiers in this field.Keywords: complex networktransportationreviewtopologyurban systems AcknowledgementsThe author thanks Dr. Bin Jiang for his helpful suggestions on this work. Many sincere thanks to the three reviewers for their valuable comments, which helped to improve the manuscript.

Hadronic transitions of χcJ→ηcπ+π− (J=0, 1, 2) are searched for using a sample of 1.06×108 ψ(3686) events collected with the BESIII detector at the BEPCII storage ring. The ηc is reconstructed with K0SK±π∓ and K+K−π0 final states. No signals are observed in any of the three χcJ states in either ηc decay mode. At the 90% confidence level, the upper limits are determined to be B(χc0→ηcπ+π−)<0.07%, B(χc1→ηcπ+π−)<0.32%, and B(χc2→ηcπ+π−)<0.54%. The upper limit of B(χc1→ηcπ+π−) is lower than the existing theoretical prediction by almost an order of magnitude. The branching fractions of χcJ→K0SK±π∓π+π−, K+K−π+π−π0, ωK+K−, and ϕπ+π−π0 J=0, 1, 2) are measured for the first time.Received 23 August 2012DOI:https://doi.org/10.1103/PhysRevD.87.012002© 2013 American Physical Society

Using a sample of 1.06 \times 10^8 \psi^{\prime} decays collected by the BESIII detector, \chi_{c0} and \chi_{c2} decays into \pi^0\pi^0 and \eta\eta are studied. The branching fraction results are Br(\chi_{c0}\to\pi^0\pi^0)=(3.23\pm 0.03\pm0.23 \pm 0.14)\times 10^{-3}, Br(\chi_{c2}\to\pi^0\pi^0)=(8.8\pm 0.2\pm 0.6\pm0.4)\times 10^{-4}, Br(\chi_{c0}\to\eta\eta)=(3.44\pm 0.10\pm0.24 \pm0.2)\times 10^{-3}, and Br(\chi_{c2}\to\eta\eta)=(6.5\pm 0.4\pm 0.5\pm 0.3)\times 10^{-4}, where the uncertainties are statistical, systematic due to this measurement, and systematic due to the branching fractions of \psi^{\prime}\to\gamma\chi_{cJ}, respectively. The results provide information on the decay mechanism of \chi_c states into pseudoscalars.

With a sample of (225.2±2.8)×10(6) J/ψ events registered in the BESIII detector, J/ψ→γπ(+)π(-)η(') is studied using two η(') decay modes: η(')→π(+)π(-)η and η(')→γρ(0). The X(1835), which was previously observed by BESII, is confirmed with a statistical significance that is larger than 20σ. In addition, in the π(+)π(-)η(') invariant-mass spectrum, the X(2120) and the X(2370), are observed with statistical significances larger than 7.2σ and 6.4σ, respectively. For the X(1835), the angular distribution of the radiative photon is consistent with expectations for a pseudoscalar.

The decays $\chi_{cJ}\to\gamma V$ ($V=\phi, \rho^0, \omega$) are studied with a sample of radiative $\psip\to\gamma\chi_{cJ}$ events in a sample of $(1.06\pm0.04)\times 10^{8} \psip$ events collected with the BESIII detector. The branching fractions are determined to be: ${\cal B}(\chi_{c1}\to \gamma\phi)=(25.8\pm 5.2\pm 2.3)\times 10^{-6}$, ${\cal B}(\chi_{c1}\to \gamma\rho^0)=(228\pm 13\pm 22)\times 10^{-6}$, and ${\cal B}(\chi_{c1}\to \gamma\omega)=(69.7\pm 7.2\pm 6.6)\times 10^{-6}$. The decay $\chi_{c1}\to \gamma\phi$ is observed for the first time. Upper limits at the 90% confidence level on the branching fractions for $\chi_{c0}$ and $\chict$ decays into these final states are determined. In addition, the fractions of the transverse polarization component of the vector meson in $\chi_{c1}\to \gamma V$ decays are measured to be $0.29_{-0.12-0.09}^{+0.13+0.10}$ for $\chi_{c1}\to \gamma\phi$, $0.158\pm 0.034^{+0.015}_{-0.014}$ for $\chi_{c1}\to \gamma\rho^0$, and $0.247_{-0.087-0.026}^{+0.090+0.044}$ for $\chi_{c1}\to \gamma\omega$, respectively. The first errors are statistical and the second ones are systematic.

From December 2011 to May 2014, about 5 fb−1 of data were taken with the BESIII detector at center-of-mass energies between 3.810 GeV and 4.600 GeV to study the charmonium-like states and higher excited charmonium states. The time-integrated luminosity of the collected data sample is measured to a precision of 1% by analyzing events produced by the large-angle Bhabha scattering process.

Using data collected with the BESIII detector operating at the Beijing Electron Positron Collider at center-of-mass energies of sqrt[s]=4.23, 4.26, and 4.36 GeV, we observe e(+)e(-)→π(0)π(0)hc for the first time. The Born cross sections are measured and found to be about half of those of e(+)e(-)→π(+)π(-)hc within less than 2σ. In the π(0)hc mass spectrum, a structure at 4.02 GeV/c(2) is found. It is most likely to be the neutral isospin partner of the Zc(4020)(±) observed in the process of e(+)e(-)→π(+)π(-)hc being found. A fit to the π(0)hc invariant mass spectrum, with the width of the Zc(4020)(0) fixed to that of its charged isospin partner and possible interferences with non-Zc(4020)(0) amplitudes neglected, gives a mass of (4023.9±2.2±3.8) MeV/c(2) for the Zc(4020)(0), where the first error is statistical and the second systematic.

Based on data samples collected with the BESIII detector at the BEPCII collider at nine center of mass energies from 4.21 to 4.42 GeV, we search for the production of e^{+}e^{-}→ωχ_{cJ} (J=0, 1, 2). The process e^{+}e^{-}→ωχ_{c0} is observed for the first time, and the Born cross sections at sqrt[s]=4.23 and 4.26 GeV are measured to be (55.4±6.0±5.9) and (23.7±5.3±3.5) pb, respectively, where the first uncertainties are statistical and the second are systematic. The ωχ_{c0} signals at the other seven energies and the e^{+}e^{-}→ωχ_{c1} and ωχ_{c2} signals are not significant, and the upper limits on the cross sections are determined. By examining the ωχ_{c0} cross section as a function of center of mass energy, we find that it is inconsistent with the line shape of the Y(4260) observed in e^{+}e^{-}→π^{+}π^{-}J/ψ. Assuming the ωχ_{c0} signals come from a single resonance, we extract the mass and width of the resonance to be (4230±8±6) MeV/c^{2} and (38±12±2) MeV, respectively, and the statistical significance is more than 9σ.

We report the first measurement of absolute hadronic branching fractions of ${\mathrm{\ensuremath{\Lambda}}}_{c}^{+}$ baryon at the ${\mathrm{\ensuremath{\Lambda}}}_{c}^{+}{\overline{\mathrm{\ensuremath{\Lambda}}}}_{c}^{\ensuremath{-}}$ production threshold, in the 30 years since the ${\mathrm{\ensuremath{\Lambda}}}_{c}^{+}$ discovery. In total, 12 Cabibbo-favored ${\mathrm{\ensuremath{\Lambda}}}_{c}^{+}$ hadronic decay modes are analyzed with a double-tag technique, based on a sample of $567\text{ }\text{ }{\mathrm{pb}}^{\ensuremath{-}1}$ of ${e}^{+}{e}^{\ensuremath{-}}$ collisions at $\sqrt{s}=4.599\text{ }\text{ }\mathrm{GeV}$ recorded with the BESIII detector. A global least-squares fitter is utilized to improve the measured precision. Among the measurements for twelve ${\mathrm{\ensuremath{\Lambda}}}_{c}^{+}$ decay modes, the branching fraction for ${\mathrm{\ensuremath{\Lambda}}}_{c}^{+}\ensuremath{\rightarrow}p{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}$ is determined to be $(5.84\ifmmode\pm\else\textpm\fi{}0.27\ifmmode\pm\else\textpm\fi{}0.23)%$, where the first uncertainty is statistical and the second is systematic. In addition, the measurements of the branching fractions of the other 11 Cabibbo-favored hadronic decay modes are significantly improved.

Using a data sample collected with the BESIII detector operating at the BEPCII storage ring, we observe a new neutral state Z_{c}(3900)^{0} with a significance of 10.4σ. The mass and width are measured to be 3894.8±2.3±3.2 MeV/c^{2} and 29.6±8.2±8.2 MeV, respectively, where the first error is statistical and the second systematic. The Born cross section for e^{+}e^{-}→π^{0}π^{0}J/ψ and the fraction of it attributable to π^{0}Z_{c}(3900)^{0}→π^{0}π^{0}J/ψ in the range E_{c.m.}=4.19-4.42 GeV are also determined. We interpret this state as the neutral partner of the four-quark candidate Z_{c}(3900)^{±}.

The Technical Design for the COMET Phase-I experiment is presented in this paper. COMET is an experiment at J-PARC, Japan, which will search for neutrinoless conversion of muons into electrons in the field of an aluminium nucleus ($\mu-e$ conversion, $\mu^- N \to e^- N$); a lepton flavor violating process. The experimental sensitivity goal for this process in the Phase-I experiment is $3.1\times10^{-15}$, or 90 % upper limit of branching ratio of $7\times 10^{-15}$, which is a factor of 100 improvement over the existing limit. The expected number of background events is 0.032. To achieve the target sensitivity and background level, the 3.2 kW 8 GeV proton beam from J-PARC will be used. Two types of detectors, CyDet and StrECAL, will be used for detecting the \mue conversion events, and for measuring the beam-related background events in view of the Phase-II experiment, respectively. Results from simulation on signal and background estimations are also described.

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 $e^+e^-\to Z_c(4020)^+\pi^-+c.c.\to J/\psi\pi^+\pi^-$.

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.

From 2011 to 2014, the BESIII experiment collected about 5 fb−1 data at center-of-mass energies around 4 GeV for the studies of the charmonium-like and higher excited charmonium states. By analyzing the di-muon process e+e− → γISR/FSRμ+μ−, the center-of-mass energies of the data samples are measured with a precision of 0.8 MeV. The center-of-mass energy is found to be stable for most of the time during data taking.

The process of ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}p\overline{p}$ is studied at 22 center-of-mass energy points ($\sqrt{s}$) from 2.00 to 3.08 GeV, exploiting $688.5\text{ }\text{ }{\mathrm{pb}}^{\ensuremath{-}1}$ of data collected with the BESIII detector operating at the BEPCII collider. The Born cross section (${\ensuremath{\sigma}}_{p\overline{p}}$) of ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}p\overline{p}$ is measured with the energy-scan technique and it is found to be consistent with previously published data, but with much improved accuracy. In addition, the electromagnetic form-factor ratio ($|{G}_{E}/{G}_{M}|$) and the value of the effective ($|{G}_{\text{eff}}|$), electric ($|{G}_{E}|$), and magnetic ($|{G}_{M}|$) form factors are measured by studying the helicity angle of the proton at 16 center-of-mass energy points. $|{G}_{E}/{G}_{M}|$ and $|{G}_{M}|$ are determined with high accuracy, providing uncertainties comparable to data in the spacelike region, and $|{G}_{E}|$ is measured for the first time. We reach unprecedented accuracy, and precision results in the timelike region provide information to improve our understanding of the proton inner structure and to test theoretical models which depend on nonperturbative quantum chromodynamics.

The complicated structure of the neutron cannot be calculated using first-principles calculations due to the large colour charge of quarks and the self-interaction of gluons. Its simplest structure observables are the electromagnetic form factors1, which probe our understanding of the strong interaction. Until now, a small amount of data has been available for the determination of the neutron structure from the time-like kinematical range. Here we present measurements of the Born cross section of electron–positron annihilation reactions into a neutron and anti-neutron pair, and determine the neutron’s effective form factor. The data were recorded with the BESIII experiment at centre-of-mass energies between 2.00 and 3.08 GeV using an integrated luminosity of 647.9 pb−1. Our results improve the statistics on the neutron form factor by more than a factor of 60 over previous measurements, demonstrating that the neutron form factor data from annihilation in the time-like regime is on par with that from electron scattering experiments. The effective form factor of the neutron shows a periodic behaviour, similar to earlier observations of the proton form factor. Future works—both theoretical and experimental—will help illuminate the origin of this oscillation of the electromagnetic structure observables of the nucleon. Form factors encode the structure of nucleons. Measurements from electron–positron annihilation at BESIII reveal an oscillating behaviour of the neutron electromagnetic form factor, and clarify a long-standing photon–nucleon interaction puzzle.

Abstract Using inclusive decays of <?CDATA $J/\psi $?> , a precise determination of the number of <?CDATA $J/\psi $?> events collected with the BESIII detector was performed. For the two data sets taken in 2009 and 2012, the numbers of <?CDATA $J/\psi $?> events were recalculated to be <?CDATA $ (224.0 \pm 1.3)\times10^6 $?> and <?CDATA $ (1088.5 \pm 4.4)\times10^6 $?> , respectively; these numbers are in good agreement with the previous measurements. For the <?CDATA $J/\psi $?> sample taken in 2017–2019, the number of events was determined to be <?CDATA $ (8774.0 \pm 39.4)\times10^{6} $?> . The total number of <?CDATA $J/\psi $?> events collected with the BESIII detector was determined to be <?CDATA $ (10087 \pm 44)\times10^{6} $?> , where the uncertainty is dominated by systematic effects, and the statistical uncertainty is negligible.

The integrated luminosities of the data samples collected in the BESIII experiment in 2016--2017 at center-of-mass energies between 4.19 and 4.28 GeV are measured with a precision better than 1% by analyzing large-angle Bhabha scattering events. The integrated luminosities of the old data sets collected in 2010--2014 are updated by considering correction related to the detector performance, offsettting the effect of newly discovered readout errors in the electromagnetic calorimeter that happen haphazardly.

We report the observation of a narrow peak in the K(S)K-pi(+) invariant mass distribution in a sample of exclusive B-->KK(S)K-pi(+) decays collected with the Belle detector at the KEKB asymmetric e(+)e(-) collider. The measured mass of the peak is M=3654+/-6(stat)+/-8(syst) MeV/c(2), and we place a 90% confidence level upper limit on the width of Gamma<55 MeV/c(2). The properties agree with heavy-quark potential model expectations for the eta(c)(2S) meson, the n=2 singlet S charmonium state.

We report results on the Dalitz analysis of three-body charmless B + → K + π + π -and B + → K + K + K -decays based on a 140 fb -1 data sample collected with the Belle detector.Measurements of branching fractions for quasi-two-body decays to scalar-pseudoscalar states: B + → f 0 (980)K + , B + → K * 0 (1430) 0 π + , and to vector-pseudoscalar states:Upper limits on decays to some pseudoscalar-tensor final states are reported.We also report the measurement of the B + → χ c0 K + branching fraction in two χ c0 decays channels: χ c0 → π + π -and χ c0 → K + K -.

We have searched for a CP violation signature arising from an electric dipole moment (dτ) of the τ lepton in the e+e−→τ+τ− reaction. Using an optimal observable method and 29.5 fb−1 of data collected with the Belle detector at the KEKB collider at s=10.58 GeV, we find Re(dτ)=(1.15±1.70)×10−17 ecm and Im(dτ)=(−0.83±0.86)×10−17 ecm and set the 95% confidence level limits −2.2×10−17<Re(dτ)<4.5×10−17 ecm and −2.5×10−17<Im(dτ)<0.8×10−17 ecm.

We report evidence for the decay ${B}^{0}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{0}{\ensuremath{\pi}}^{0}$. The analysis is based on a data sample of ${\mathrm{152}\mathrm{\ifmmode\times\else\texttimes\fi{}}\mathrm{10}}^{6}$ $B\overline{B}$ pairs collected at the $\ensuremath{\Upsilon}(4S)$ resonance with the Belle detector at the KEKB ${e}^{+}{e}^{\ensuremath{-}}$ storage ring. We detect a signal for ${B}^{0}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{0}{\ensuremath{\pi}}^{0}$ with a significance of 3.4 standard deviations, and measure the branching fraction to be $\mathrm{[}\mathrm{1.7}\ifmmode\pm\else\textpm\fi{}\mathrm{0.6}\mathrm{(}\mathrm{s}\mathrm{t}\mathrm{a}\mathrm{t}\mathrm{)}\ifmmode\pm\else\textpm\fi{}\mathrm{0.2}\mathrm{(}\mathrm{s}\mathrm{y}\mathrm{s}\mathrm{t}\mathrm{)}\mathrm{]}\ifmmode\times\else\texttimes\fi{}{\mathrm{10}}^{\ensuremath{-}\mathrm{6}}$.

We present a new analysis of double charmonium production in e + e -annihilation.The observation of the processes e + e -→ J/ψ ηc, J/ψ χc0, and J/ψ ηc(2S) is confirmed using a dataset more than three times larger than that of Belle's previous report, and no evidence for the process e + e -→ J/ψ J/ψ is found.We perform an angular analysis for J/ψ ηc production and set an upper limit on the production of J/ψ J/ψ.Processes of the type e + e -→ ψ(2S)(cc)res have been observed for the first time; their rates are found to be comparable to those of e + e -→ J/ψ(cc)res processes.

We report measurements of the properties of the D(+)(sJ)(2317) and D(+)(sJ)(2457) resonances produced in continuum e(+)e(-) annihilation near sqrt[s]=10.6 GeV. The analysis is based on an 86.9 fb(-1) data sample collected with the Belle detector at KEKB. We determine the masses to be M(D(+)(sJ)(2317))=2317.2+/-0.5(stat)+/-0.9(syst) MeV/c(2) and M(D(+)(sJ)(2457))=2456.5+/-1.3(stat)+/-1.3(syst) MeV/c(2). We observe the radiative decay mode D(+)(sJ)(2457)-->D(+)(s)gamma and the dipion decay mode D(+)(sJ)(2457)-->D(+)(s)pi(+)pi(-) and determine their branching fractions. No corresponding decays are observed for the D(sJ)(2317) state. These results are consistent with the spin-parity assignments of 0(+) for the D(sJ)(2317) and 1(+) for the D(sJ)(2457).

The decays of J/ψ→ηϕf0(980)[η→γγ,ϕ→K+K−,f0(980)→π+π−] are analyzed using a sample of 5.8×107 J/ψ events collected with the BESII detector at the Beijing Electron-Positron Collider. A structure at around 2.18 GeV/c2 with about 5σ significance is observed in the ϕf0(980) invariant mass spectrum. A fit with a Breit-Wigner function gives the peak mass and width of m=2.186±0.010(stat)±0.006(syst) GeV/c2 and Γ=0.065±0.023(stat)±0.017(syst) GeV/c2, respectively, which are consistent with those of Y(2175), observed by the BABAR Collaboration in the initial-state radiation process e+e−→γISRϕf0(980). The production branching ratio is determined to be Br(J/ψ→ηY(2175))Br(Y(2175)→ϕf0(980))Br(f0(980)→π+π−)=[3.23±0.75(stat)±0.73(syst)]×10−4, assuming that the Y(2175) is a 1−− state.Received 7 December 2007DOI:https://doi.org/10.1103/PhysRevLett.100.102003©2008 American Physical Society

We present the first measurement of decay amplitudes in B→φK* and measurements of branching fractions in B→φK(*) decays based on 78.1 fb−1 of data recorded at the Υ(4S) resonance with the Belle detector at the KEKB e+e− storage ring. The decay amplitudes for the different φK*0 helicity states are measured from the angular distributions of final state particles in the transversity basis. The longitudinal and transverse complex amplitudes are |A0|2=0.43±0.09±0.04, |A⊥|2=0.41±0.10±0.04, arg(A∥)=−2.57±0.39±0.09, and arg(A⊥)=0.48±0.32±0.06. The direct CP-violating asymmetries are found to be consistent with zero.Received 8 July 2003DOI:https://doi.org/10.1103/PhysRevLett.91.201801©2003 American Physical Society

Based on 58 million BESII J/ψ events, the K¯∗(892)0K+π− channel in K+K−π+π− is studied. A clear low mass enhancement in the invariant mass spectrum of K+π− is observed. The low mass enhancement does not come from background of other J/ψ decay channels, nor from phase space. Two independent partial wave analyses have been performed. Both analyses favor that the low mass enhancement is the κ, an iso-spinor scalar resonant state. The average mass and width of the κ in the two analyses are 878±23−55+64MeV/c2 and 499±52−87+55MeV/c2, respectively, corresponding to a pole at (841±30−73+81)−i(309±45−72+48)MeV/c2.

$R$ measurement data taken with the BESII detector at center-of-mass energies between 3.7 and 5.0 GeV is fitted to determine resonance parameters (mass, total width, electron width) of the high mass charmonium states, $ψ(3770)$, $ψ(4040)$, $ψ(4160)$ and $ψ(4415)$. Various effects, including the relative phases between the resonances, interferences, the energy-dependence of the full widths, and the initial state radiative correction, are examined. The results are compared to previous studies.

We present measurements of the charmonium state $h_c(^1P_1)$ made with 106M $\psi'$ events collected by BESIII at BEPCII. Clear signals are observed for $\psi'\to\pi^0 h_c$ with and without the subsequent radiative decay $h_c\to\gamma\eta_c$. First measurements of the absolute branching ratios $\mathcal{B}(\psi' \to\pi^0 h_c) = (8.4 \pm 1.3 \pm 1.0) \times 10^{-4}$ and $\mathcal{B}(h_c \to \gamma \eta_c) = (54.3 \pm 6.7 \pm5.2)%$ are presented. A statistics-limited determination of the previously unmeasured $h_c$ width leads to an upper limit $\Gamma(h_c)<1.44 $MeV (90% confidence). Measurements of $M(h_c) = 3525.40 \pm 0.13 \pm 0.18 $MeV/$c^2$ and $\mathcal{B}(\psi'\to \pi^0 h_c) \times \mathcal{B}(h_c \to \gamma\eta_c) = (4.58 \pm 0.40 \pm 0.50) \times 10^{-4}$ are consistent with previous results.

The decays $J/\psi \rightarrow \gamma \pi^+\pi^-\pi^0$ and $J/\psi \rightarrow \gamma \pi^0\pi^0\pi^0$ are analyzed using a sample of 225 million $\jpsi$ events collected with the BESIII detector. The decay of $\eta(1405)\ar f_{0}(980)\pi^0$ with a large isospin violation is observed for the first time. The width of the $f_{0}(980)$ observed in the dipion mass spectra is anomalously narrower than the world average. Decay rates for three-pion decays of the $\eta'$ are also measured precisely.

We report results of a study of doubly charmed baryons and charmed strange baryons.The analysis is performed using a 980 fb -1 data sample collected with the Belle detector at the KEKB asymmetric-energy e þ e -collider.We search for doubly charmed baryons ΞNo significant signal is observed.We also search for two excited charmed strange baryons, Ξ c ð3055Þ þ and Ξ c ð3123Þ þ with the Σ þþ c ð2455ÞK -and Σ þþ c ð2520ÞK -final states.The Ξ c ð3055Þ þ signal is observed with a significance of 6.6 standard deviations including systematic uncertainty, while no signature of the Ξ c ð3123Þ þ is seen.We also study properties of the Ξ c ð2645Þ þ and measure a width of 2.6 AE 0.2ðstatÞ AE 0.4ðsystÞ MeV=c 2 , which is the first significant determination.

In an analysis of a $2.92\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ data sample taken at 3.773 GeV with the BESIII detector operated at the BEPCII collider, we measure the absolute decay branching fractions $\mathcal{B}({D}^{0}\ensuremath{\rightarrow}{K}^{\ensuremath{-}}{e}^{+}{\ensuremath{\nu}}_{e})=(3.505\ifmmode\pm\else\textpm\fi{}0.014\ifmmode\pm\else\textpm\fi{}0.033)%$ and $\mathcal{B}({D}^{0}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{\ensuremath{-}}{e}^{+}{\ensuremath{\nu}}_{e})=(0.295\ifmmode\pm\else\textpm\fi{}0.004\ifmmode\pm\else\textpm\fi{}0.003)%$. From a study of the differential decay rates we obtain the products of hadronic form factor and the magnitude of the Cabibbo-Kobayashi- Maskawa (CKM) matrix element ${f}_{+}^{K}(0)|{V}_{cs}|=0.7172\ifmmode\pm\else\textpm\fi{}0.0025\ifmmode\pm\else\textpm\fi{}0.0035$ and ${f}_{+}^{\ensuremath{\pi}}(0)|{V}_{cd}|=0.1435\ifmmode\pm\else\textpm\fi{}\phantom{\rule{0ex}{0ex}}0.0018\ifmmode\pm\else\textpm\fi{}0.0009$. Combining these products with the values of $|{V}_{cs(d)}|$ from the SM constraint fit, we extract the hadronic form factors ${f}_{+}^{K}(0)=0.7368\ifmmode\pm\else\textpm\fi{}0.0026\ifmmode\pm\else\textpm\fi{}0.0036$ and ${f}_{+}^{\ensuremath{\pi}}(0)=0.6372\ifmmode\pm\else\textpm\fi{}0.0080\ifmmode\pm\else\textpm\fi{}\phantom{\rule{0ex}{0ex}}0.0044$, and their ratio ${f}_{+}^{\ensuremath{\pi}}(0)/{f}_{+}^{K}(0)=0.8649\ifmmode\pm\else\textpm\fi{}0.0112\ifmmode\pm\else\textpm\fi{}0.0073$. These form factors and their ratio are used to test unquenched lattice QCD calculations of the form factors and a light cone sum rule (LCSR) calculation of their ratio. The measured value of ${f}_{+}^{K(\ensuremath{\pi})}(0)|{V}_{cs(d)}|$ and the lattice QCD value for ${f}_{+}^{K(\ensuremath{\pi})}(0)$ are used to extract values of the CKM matrix elements of $|{V}_{cs}|=0.9601\ifmmode\pm\else\textpm\fi{}0.0033\ifmmode\pm\else\textpm\fi{}0.0047\ifmmode\pm\else\textpm\fi{}0.0239$ and $|{V}_{cd}|=0.2155\ifmmode\pm\else\textpm\fi{}0.0027\ifmmode\pm\else\textpm\fi{}0.0014\ifmmode\pm\else\textpm\fi{}0.0094$, where the third errors are due to the uncertainties in lattice QCD calculations of the form factors. Using the LCSR value for ${f}_{+}^{\ensuremath{\pi}}(0)/{f}_{+}^{K}(0)$, we determine the ratio $|{V}_{cd}|/|{V}_{cs}|=0.238\ifmmode\pm\else\textpm\fi{}0.004\ifmmode\pm\else\textpm\fi{}0.002\ifmmode\pm\else\textpm\fi{}0.011$, where the third error is from the uncertainty in the LCSR normalization. In addition, we measure form factor parameters for three different theoretical models that describe the weak hadronic charged currents for these two semileptonic decays. All of these measurements are the most precise to date.

A partial wave analysis of the pp¯ mass-threshold enhancement in the reaction J/ψ→γpp¯ is used to determine its J(PC) quantum numbers to be 0(-+), its peak mass to be below threshold at M=1832(-5)(+19)(stat)(-17)(+18)(syst)±19(model) MeV/c(2), and its total width to be Γ<76 MeV/c(2) at the 90% C.L. The product of branching ratios is measured to be BR[J/ψ→γX(pp¯)]BR[X(pp¯)→pp¯]=[9.0(-1.1)(+0.4)(stat)(-5.0)(+1.5)(syst)±2.3(model)]×10(-5). A similar analysis performed on ψ(3686)→γpp¯ decays shows, for the first time, the presence of a corresponding enhancement with a production rate relative to that for J/ψ decays of R=[5.08(-0.45)(+0.71)(stat)(-3.58)(+0.67)(syst)±0.12(model)]%.

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We report a study of the process e^{+}e^{-}→(D^{*}D[over ¯]^{*})^{0}π^{0} using e^{+}e^{-} collision data samples with integrated luminosities of 1092 pb^{-1} at sqrt[s]=4.23 GeV and 826 pb^{-1} at sqrt[s]=4.26 GeV collected with the BESIII detector at the BEPCII storage ring. We observe a new neutral structure near the (D^{*}D[over ¯]^{*})^{0} mass threshold in the π^{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_{-4.7}^{+2.0}±3.1) MeV/c^{2} and (23.0±6.0±1.0) MeV, respectively. The Born cross sections of e^{+}e^{-}→Z_{c}(4025)^{0}π^{0}→(D^{*}D[over ¯]^{*})^{0}π^{0} are measured to be (61.6±8.2±9.0) pb at sqrt[s]=4.23 GeV and (43.4±8.0±5.4) pb at sqrt[s]=4.26 GeV. The first uncertainties are statistical and the second are systematic.

We report the first absolute measurement of the branching fraction of $\Lambda^+_{c}\rightarrow \Lambda e^+\nu_e$. This measurement is based on 567 pb$^{-1}$ of $e^+e^-$ annihilation data produced at $\sqrt{s}=4.599$ GeV, which is just above the $\Lambda^+_c\bar{\Lambda}^-_c$ threshold. The data were collected with the BESIII detector at the BEPCII storage rings. The branching fraction is determined to be $\mathcal B({\Lambda^+_c\rightarrow \Lambda e^+\nu_e})=(3.63\pm0.38({\rm stat})\pm0.20({\rm syst}))\%$, representing a more than twofold improvement in precision upon previously published results. As the branching fraction for $\Lambda^+_{c}\rightarrow \Lambda e^+\nu_e$ is the benchmark for those of other $\Lambda^+_c$ semileptonic channels, our result provides a unique test of different theoretical models, which is the most stringent to date.

A neutral structure in the DD[over ¯]^{*} system around the DD[over ¯]^{*} mass threshold is observed with a statistical significance greater than 10σ in the processes e^{+}e^{-}→D^{+}D^{*-}π^{0}+c.c. and e^{+}e^{-}→D^{0}D[over ¯]^{*0}π^{0}+c.c. at sqrt[s]=4.226 and 4.257 GeV in the BESIII experiment. The structure is denoted as Z_{c}(3885)^{0}. Assuming the presence of a resonance, its pole mass and width are determined to be [3885.7_{-5.7}^{+4.3}(stat)±8.4(syst)] MeV/c^{2} and [35_{-12}^{+11}(stat)±15(syst)] MeV, respectively. The Born cross sections are measured to be σ[e^{+}e^{-}→Z_{c}(3885)^{0}π^{0},Z_{c}(3885)^{0}→DD[over ¯]^{*}]=[77±13(stat)±17(syst)] pb at 4.226 GeV and [47±9(stat)±10(syst)] pb at 4.257 GeV. The ratio of decay rates B[Z_{c}(3885)^{0}→D^{+}D^{*-}+c.c.]/B[Z_{c}(3885)^{0}→D^{0}D[over ¯]^{*0}+c.c.] is determined to be 0.96±0.18(stat)±0.12(syst), consistent with no isospin violation in the process, Z_{c}(3885)^{0}→DD[over ¯]^{*}.

Using data samples collected with the BESIII detector at the BEPCII collider, we measure the Born cross section of ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}p\overline{p}$ at 12 center-of-mass 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.

This paper examines the relationship between different street centralities and land-use types in Stockholm. Major centrality measures of closeness, betweenness, and straightness are calculated at both global and local levels in both the primary and dual representations of the urban street network. Adaptive kernel density estimation is adopted to transform all unevenly distributed datasets to one continuous raster framework for further analysis. After computing statistical and spatial distribution of each centrality and land-use density map, we find that the density of each street centrality is highly correlated with one type of land use. Results imply that various centralities representing street properties from different aspects can capture the land development patterns of different land-use types by reflecting human activities, and are consequently important indicators to describe urban structure.

The process $e^{+}e^{-}\rightarrow\Lambda\bar{\Lambda}$ is studied using data samples at $\sqrt{s}=2.2324$, 2.400, 2.800 and 3.080 GeV collected with the BESIII detector operating at the BEPCII collider. The Born cross section is measured at $\sqrt{s}$=2.2324 GeV, which is 1.0 MeV above the $\Lambda\bar{\Lambda}$ mass threshold, to be $305\pm45^{+66}_{-36}$ pb, where the first uncertainty is statistical and the second systematic. The substantial cross section near threshold is significantly larger than that expected from theory, which predicts the cross section to vanish at threshold. The Born cross sections at $\sqrt{s}$=2.400, 2.800 and 3.080 GeV are measured and found to be consistent with previous experimental results, but with improved precision. Finally, the corresponding effective electromagnetic form factors of $\Lambda$ are deduced.

The cross section of the e^{+}e^{-}→Λ_{c}^{+}Λ[over ¯]_{c}^{-} process is measured with unprecedented precision using data collected with the BESIII detector at sqrt[s]=4574.5, 4580.0, 4590.0 and 4599.5 MeV. The nonzero cross section near the Λ_{c}^{+}Λ[over ¯]_{c}^{-} production threshold is cleared. At center-of-mass energies sqrt[s]=4574.5 and 4599.5 MeV, the higher statistics data enable us to measure the Λ_{c} polar angle distributions. From these, the Λ_{c} electric over magnetic form-factor ratios (|G_{E}/G_{M}|) are measured for the first time. They are found to be 1.14±0.14±0.07 and 1.23±0.05±0.03, respectively, where the first uncertainties are statistical and the second are systematic.

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 $(448.1\pm2.9)\times10^6$.

This paper analyzes the growth and evolution of topological features of the US airline network over a 20-year period. It captures the change in the network system from different dimensions of complex networks such as centrality distribution and various structural properties of the network over time. We first illustrate the results of a set of measures, including degree, strength, betweenness centrality, and clustering structure. The geographic features of airport systems, spatial distance and network efficiency are also discussed in this section. In order to further capture the dynamics of the system, this paper also explores the correlation between different measures, and investigates various interactions inside the network. Overall this study offers a novel approach to understanding the growth and evolution of real physical networks.

A measurement of the number of $J/\psi$ events collected with the BESIII detector in 2009 and 2012 is performed using inclusive decays of the $J/\psi$ . The number of $J/\psi$ events taken in 2009 is recalculated to be $(223.7\pm1.4)\times 10^6$, which is in good agreement with the previous measurement, but with significantly improved precision due to improvements in the BESIII software. The number of $J/\psi$ events taken in 2012 is determined to be $(1086.9\pm 6.0)\times 10^6$. In total, the number of $J/\psi$ events collected with the BESIII detector is measured to be $(1310.6\pm 7.0)\times 10^6$, where the uncertainty is dominated by systematic effects and the statistical uncertainty is negligible.

The cross section of the process $e^{+} e^{-} \rightarrow K^{+} K^{-}$ is measured at a number of center-of-mass energies $\sqrt{s}$ from 2.00 to 3.08 GeV with the BESIII detector at the Beijing Electron Positron Collider (BEPCII). The results provide the best precision achieved so far. A resonant structure around 2.2 GeV is observed in the cross section line shape. A Breit-Wigner fit yields a mass of $M=2239.2 \pm 7.1 \pm 11.3$~and a width of $\Gamma=139.8\pm12.3\pm20.6$ MeV, where the first uncertainties are statistical and the second ones are systematic. In addition, the time-like electromagnetic form factor of the kaon is determined at the individual center-of-mass energy points.

We study the ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}\ensuremath{\gamma}\ensuremath{\omega}J/\ensuremath{\psi}$ process using $11.6\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ ${e}^{+}{e}^{\ensuremath{-}}$ annihilation data taken at center-of-mass energies from $\sqrt{s}=4.008\text{ }\text{ }\mathrm{GeV}$ to 4.600 GeV with the BESIII detector at the BEPCII storage ring. The $X(3872)$ resonance is observed for the first time in the $\ensuremath{\omega}J/\ensuremath{\psi}$ system with a significance of more than $5\ensuremath{\sigma}$. The relative decay ratio of $X(3872)\ensuremath{\rightarrow}\ensuremath{\omega}J/\ensuremath{\psi}$ and ${\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}J/\ensuremath{\psi}$ is measured to be $\mathcal{R}={1.6}_{\ensuremath{-}0.3}^{+0.4}\ifmmode\pm\else\textpm\fi{}0.2$, where the first uncertainty is statistical and the second systematic (the same hereafter). The $\sqrt{s}$-dependent cross section of ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}\ensuremath{\gamma}X(3872)$ is also measured and investigated, and it can be described by a single Breit-Wigner resonance, referred to as the $Y(4200)$, with a mass of ${4200.6}_{\ensuremath{-}13.3}^{+7.9}\ifmmode\pm\else\textpm\fi{}3.0\text{ }\text{ }\mathrm{MeV}/{c}^{2}$ and a width of ${115}_{\ensuremath{-}26}^{+38}\ifmmode\pm\else\textpm\fi{}12\text{ }\text{ }\mathrm{MeV}$. In addition, to describe the $\ensuremath{\omega}J/\ensuremath{\psi}$ mass distribution above $3.9\text{ }\text{ }\mathrm{GeV}/{c}^{2}$, we need at least one additional Breit-Wigner resonance, labeled as $X(3915)$, in the fit. The mass and width of the $X(3915)$ are determined. The resonant parameters of the $X(3915)$ agree with those of the $Y(3940)$ in $B\ensuremath{\rightarrow}K\ensuremath{\omega}J/\ensuremath{\psi}$ and of the $X(3915)$ in $\ensuremath{\gamma}\ensuremath{\gamma}\ensuremath{\rightarrow}\ensuremath{\omega}J/\ensuremath{\psi}$ observed by the Belle and BABAR experiments within errors.

Gas detectors for elementary particles require F-based gases for optimal performance. Recent regulations demand the use of environmentally unfriendly F-based gases to be limited or banned. This work studies properties of potential eco-friendly gas replacements by computing the physical and chemical parameters relevant for use as detector media, and suggests candidates to be considered for experimental investigation.

The cross section of the process ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{D}^{0}{D}^{*\ensuremath{-}}$ for center-of-mass energies from 4.05 to 4.60 GeV is measured precisely using data samples collected with the BESIII detector operating at the BEPCII storage ring. Two enhancements are clearly visible in the cross section around 4.23 and 4.40 GeV. Using several models to describe the dressed cross section yields stable parameters for the first enhancement, which has a mass of $4228.6\ifmmode\pm\else\textpm\fi{}4.1\ifmmode\pm\else\textpm\fi{}6.3\text{ }\text{ }\mathrm{MeV}/{c}^{2}$ and a width of $77.0\ifmmode\pm\else\textpm\fi{}6.8\ifmmode\pm\else\textpm\fi{}6.3\text{ }\text{ }\mathrm{MeV}$, where the first uncertainties are statistical and the second ones are systematic. Our resonant mass is consistent with previous observations of the $Y(4220)$ state and the theoretical prediction of a $D{\overline{D}}_{1}(2420)$ molecule. This result is the first observation of $Y(4220)$ associated with an open-charm final state. Fits with three resonance functions with additional $Y(4260)$, $Y(4320)$, $Y(4360)$, $\ensuremath{\psi}(4415)$, or a new resonance do not show significant contributions from either of these resonances. The second enhancement is not from a single known resonance. It could contain contributions from $\ensuremath{\psi}(4415)$ and other resonances, and a detailed amplitude analysis is required to better understand this enhancement.

The cross section of the process $e^+e^- \rightarrow \omega \chi_{c0}$ is measured at center-of-mass energies from $\sqrt{s} =$ 4.178 to 4.278 GeV using a data sample of 7 fb$^{-1}$ collected with the BESIII detector operating at the BEPCII storage ring. The dependence of the cross section on $\sqrt{s}$ shows a resonant structure with mass of $(4218.5\pm1.6(\text{stat.})\pm4.0(\text{syst.}))$ MeV/$c^2$ and width of $(28.2\pm3.9(\text{stat.})\pm1.6(\text{syst.}))$ MeV, respectively. This observation confirms and improves upon the result of a previous study. The angular distribution of the $e^+e^- \rightarrow \omega \chi_{c0}$ process is extracted for the first time.

From 1310.6×106 J/ψ and 448.1×106 ψ(3686) events collected with the BESIII experiment, we report the first observation of Σ+ and ¯Σ− spin polarization in e+e−→J/ψ[ψ(3686)]→Σ+¯Σ− decays. The relative phases of the form factors ΔΦ have been measured to be (−15.5±0.7±0.5)° and (21.7±4.0±0.8)° with J/ψ and ψ(3686) data, respectively. The nonzero value of ΔΦ allows for a direct and simultaneous measurement of the decay asymmetry parameters of Σ+→pπ0(α0=−0.998±0.037±0.009) and ¯Σ−→¯pπ0(¯α0=0.990±0.037±0.011), the latter value being determined for the first time. The average decay asymmetry, (α0−¯α0)/2, is calculated to be −0.994±0.004±0.002. The CP asymmetry ACP,Σ=(α0+¯α0)/(α0−¯α0)=−0.004±0.037±0.010 is extracted for the first time, and is found to be consistent with CP conservation.Received 17 April 2020Accepted 18 June 2020DOI:https://doi.org/10.1103/PhysRevLett.125.052004Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP3.Published by the American Physical SocietyPhysics Subject Headings (PhySH)Research AreasParticle interactionsPhysical SystemsHyperonsPropertiesCP violationParticle propertiesPolarizationParticles & Fields

The Born cross sections of the $e^{+}e^{-}\to\Sigma^{+}\bar{\Sigma}^{-}$ and $e^{+}e^{-}\to\Sigma^{-}\bar{\Sigma}^{+}$ processes are determined with high precision for center-of-mass energy from 2.3864 to 3.0200 GeV with the BESIII detector. Nonzero cross sections near threshold are observed. The resulting ratio of effective form factors for the $\Sigma^{+}$ and $\Sigma^{-}$ is consistent with 3, agreeing with the ratio of the incoherent sum of the squared charges of the $\Sigma^{+}$ and $\Sigma^{-}$ valence quarks, but disagreeing with various theoretical predictions. In addition, ratios of the $\Sigma^{+}$ electric and magnetic form factors, $|G_{E}/G_{M}|$, are obtained at three center-of-mass energies through an analysis of the angular distributions. These measurements, which are studied for the first time in the off-resonance region, provide precision experimental input for understanding baryonic structure. The observed novel features of the $\Sigma^{\pm}$ form factors require a new theoretical description for the hyperons.

The electromagnetic process e+e−→pp¯ is studied with the initial-state-radiation technique using 7.5 fb−1 of data collected by the BESIII experiment at seven energy points from 3.773 to 4.600 GeV. The Born cross section and the effective form factor of the proton are measured from the production threshold to 3.0 GeV/c2 using the pp¯ invariant-mass spectrum. The ratio of electric and magnetic form factors of the proton is determined from the analysis of the proton-helicity angular distribution.

Based on 10 billion J/ψ events collected at the BESIII experiment, a search for CP violation in Λ decay is performed in the difference between CP-odd decay parameters α_{-} for Λ→pπ^{-} and α_{+} for Λ[over ¯]→p[over ¯]π^{+} by using the process e^{+}e^{-}→J/ψ→ΛΛ[over ¯]. With a five-dimensional fit to the full angular distributions of the daughter baryon, the most precise values for the decay parameters are determined to be α_{-}=0.7519±0.0036±0.0024 and α_{+}=-0.7559±0.0036±0.0030, respectively. The Λ and Λ[over ¯] averaged value of the decay parameter is extracted to be α_{avg}=0.7542±0.0010±0.0024 with unprecedented accuracy. The CP asymmetry A_{CP}=(α_{-}+α_{+})/(α_{-}-α_{+}) is determined to be -0.0025±0.0046±0.0012, which is one of the most precise measurements in the baryon sector. The reported results for the decay parameter will play an important role in the studies of the polarizations and CP violations for the strange, charmed and beauty baryons.

Abstract The cross sections of <?CDATA $ e^+e^- \rightarrow K^+K^-J/\psi $?> at center-of-mass energies from 4.127 to 4.600 GeV are measured based on 15.6 fb <?CDATA $ ^{-1} $?> data collected with the BESIII detector operating at the BEPCII storage ring. Two resonant structures are observed in the line shape of the cross sections. The mass and width of the first structure are measured to be ( <?CDATA $ 4225.3\pm2.3\pm21.5 $?> ) MeV and ( <?CDATA $ 72.9\pm6.1\pm30.8 $?> ) MeV, respectively. They are consistent with those of the established <?CDATA $ Y(4230) $?> . The second structure is observed for the first time with a statistical significance greater than 8 σ , denoted as <?CDATA $ Y(4500) $?> . Its mass and width are determined to be ( <?CDATA $ 4484.7\pm13.3\pm24.1 $?> ) MeV and ( <?CDATA $ 111.1\pm30.1\pm15.2 $?> ) MeV, respectively. The first presented uncertainties are statistical and the second ones are systematic. The product of the electronic partial width with the decay branching fraction <?CDATA $ \Gamma(Y(4230)\to e^+ e^-) \mathcal{B}(Y(4230) \to K^+ K^- J/\psi) $?> is reported.

Abstract Using electron-positron annihilation data samples corresponding to an integrated luminosity of 4.5 fb <?CDATA $ ^{-1} $?> , collected by the BESIII detector in the energy region between <?CDATA $ 4599.53\; \,{\rm{MeV}} $?> and <?CDATA $ 4698.82\; \,{\rm{MeV}} $?> , we report the first observations of the Cabibbo-suppressed decays <?CDATA $ \Lambda_c^+\to n\pi^+\pi^0 $?> , <?CDATA $ \Lambda_c^+\to n\pi^+\pi^-\pi^+ $?> , and the Cabibbo-favored decay <?CDATA $ \Lambda_c^+\to nK^-\pi^+\pi^+ $?> with statistical significances of <?CDATA $ 7.9\sigma $?> , <?CDATA $ 7.8\sigma $?> , and <?CDATA $ &gt;10\sigma $?> , respectively. The branching fractions of these decays are measured to be <?CDATA $\mathcal{B}(\Lambda_{c}^{+}\rightarrow n\pi^{+}\pi^{0})=(0.64\pm0.09\pm0.02)$?> %, <?CDATA $\mathcal{B}(\Lambda_{c}^{+}\rightarrow n\pi^{+}\pi^{-}\pi^{+})=(0.45\pm 0.07\pm $?> <?CDATA $ 0.03)$?> %, and <?CDATA $\mathcal{B}(\Lambda_{c}^{+}\rightarrow nK^{-}\pi^{+}\pi^{+})=(1.90\pm0.08\pm0.09)$?> %, where the first uncertainties are statistical and the second are systematic. We find that the branching fraction of the decay <?CDATA $ \Lambda_{c}^{+}\rightarrow n\pi^{+}\pi^{0} $?> is about one order of magnitude higher than that of <?CDATA $ \Lambda_{c}^{+}\rightarrow n\pi^{+} $?> .

Using initial-state radiation events from a total integrated luminosity of 11.957 fb−1 of e+e− collision data collected at center-of-mass energies between 3.773 and 4.258 GeV with the BESIII detector at BEPCII, the cross section for the process e+e−→Λ¯Λ is measured in 16 Λ¯Λ invariant mass intervals from the production threshold up to 3.00 GeV/c2. The results are consistent with previous results from BABAR and BESIII, but with better precision and with narrower Λ¯Λ invariant mass intervals than BABAR.1 MoreReceived 15 March 2023Accepted 23 March 2023Corrected 28 April 2023DOI:https://doi.org/10.1103/PhysRevD.107.072005Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP3.Published by the American Physical SocietyPhysics Subject Headings (PhySH)Research AreasForm factorsParticle interactionsQuantum chromodynamicsQuark matterPhysical SystemsBaryonsLight quarksStrange quarkTechniquesLepton collidersMonte Carlo methodsParticle productionParticles & Fields

The Born cross sections of the process ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{D}^{*0}{D}^{*\ensuremath{-}}{\ensuremath{\pi}}^{+}$ at center-of-mass energies from 4.189 to 4.951 GeV are measured for the first time. The data samples used correspond to an integrated luminosity of $17.9\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ and were collected by the BESIII detector operating at the BEPCII storage ring. Three enhancements around 4.20, 4.47, and 4.67 GeV are visible. The resonances have masses of $4209.6\ifmmode\pm\else\textpm\fi{}4.7\ifmmode\pm\else\textpm\fi{}5.9\text{ }\text{ }\mathrm{MeV}/{c}^{2}$, $4469.1\ifmmode\pm\else\textpm\fi{}26.2\ifmmode\pm\else\textpm\fi{}3.6\text{ }\text{ }\mathrm{MeV}/{c}^{2}$, and $4675.3\ifmmode\pm\else\textpm\fi{}29.5\ifmmode\pm\else\textpm\fi{}3.5\text{ }\text{ }\mathrm{MeV}/{c}^{2}$ and widths of $81.6\ifmmode\pm\else\textpm\fi{}17.8\ifmmode\pm\else\textpm\fi{}9.0\text{ }\text{ }\mathrm{MeV}$, $246.3\ifmmode\pm\else\textpm\fi{}36.7\ifmmode\pm\else\textpm\fi{}9.4\text{ }\text{ }\mathrm{MeV}$, and $218.3\ifmmode\pm\else\textpm\fi{}72.9\ifmmode\pm\else\textpm\fi{}9.3\text{ }\text{ }\mathrm{MeV}$, respectively, where the first uncertainties are statistical and the second systematic. The first and third resonances are consistent with the $\ensuremath{\psi}(4230)$ and $\ensuremath{\psi}(4660)$ states, respectively, while the second one is compatible with the $\ensuremath{\psi}(4500)$ observed in the ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{K}^{+}{K}^{\ensuremath{-}}J/\ensuremath{\psi}$ process. These three charmoniumlike $\ensuremath{\psi}$ states are observed in the ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{D}^{*0}{D}^{*\ensuremath{-}}{\ensuremath{\pi}}^{+}$ process for the first time.

We study the process e^{+}e^{-}→Λ_{c}^{+}Λ[over ¯]_{c}^{-} at twelve center-of-mass energies from 4.6119 to 4.9509 GeV using data samples collected by the BESIII detector at the BEPCII collider. The Born cross sections and effective form factors (|G_{eff}|) are determined with unprecedented precision after combining the single and double-tag methods based on the decay process Λ_{c}^{+}→pK^{-}π^{+}. Flat cross sections around 4.63 GeV are obtained and no indication of the resonant structure Y(4630), as reported by Belle, is found. In addition, no oscillatory behavior is discerned in the |G_{eff}| energy dependence of Λ_{c}^{+}, in contrast to what is seen for the proton and neutron cases. Analyzing the cross section together with the polar-angle distribution of the Λ_{c}^{+} baryon at each energy point, the moduli of electric and magnetic form factors (|G_{E}| and |G_{M}|) are extracted and separated. For the first time, the energy dependence of the form factor ratio |G_{E}/G_{M}| is observed, which can be well described by an oscillatory function.

A new acylhydrazone fluorescent sensor (VN62) with excited intramolecular proton transfer (ESIPT) characteristics has been designed and synthesized through condensation of o-vanillin with 6‑hydroxy-2-naphthoic hydrazide for selective detection of Al3+ in aqueous medium. The structure of the VN62 sensor was characterized by various techniques such as 1H and 13C NMR and mass spectrometry, and also confirmed by single crystal X-ray diffraction. The VN62 sensor showed a remarkable fluorescence enhancement response to Al3+ over a broad pH range in a nearly 100 % aqueous solution without interference by most of tested metal ions and anions. Through fluorescence titration and a Job's plot experiment, the binding stoichiometry of VN62 with Al3+ was found to be 1:1. The limit of detection of VN62 toward Al3+ was determined as 39.6 nM and the binding constant was 2.66 × 104 M−1. Comprehensive analyses by HR-MS, 1H NMR and density functional theory calculations illustrated that the VN62 sensor coordinated with Al3+, forming a stable trigonal bipyramid structure complex, which blocked the ESIPT and photoinduced electron transfer processes and simultaneously promoted an intramolecular charge transfer process, thereby leading to strong cyan fluorescence. Moreover, VN62-loaded test strips were successfully applied for rapid and visual detection of Al3+. Furthermore, the VN62 sensor was used to visualize Al3+in plants and live cells. The results indicated that the VN62 sensor has great potential for detecting Al3+in biological systems.

Using a data sample of (10087±44)×106 J/ψ events collected by the BESIII detector in 2009, 2012, 2018 and 2019, the electromagnetic Dalitz process J/ψ→e+e−η(1405) is observed via the decay η(1405)→π0f0(980), f0(980)→π+π−, with a significance of about 9.8σ. The branching fraction of this decay is measured to be B(J/ψ→e+e−η(1405)→e+e−π0f0(980)→e+e−π0π+π−)=(2.04±0.20(stat)±0.08(syst))×10−7. The branching fraction ratio B(J/ψ→e+e−η(1405))/B(J/ψ→γη(1405)) is determined to be (1.36±0.17(stat)±0.06(syst))×10−2. Furthermore, an e+e− invariant mass dependent transition form factor of J/ψ→e+e−η(1405) is presented for the first time. The obtained result provides input for different theoretical models and is valuable for the improved understanding the intrinsic structure of the η(1405) meson.Received 28 July 2023Accepted 27 November 2023DOI:https://doi.org/10.1103/PhysRevD.109.012007Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP3.Published by the American Physical SocietyPhysics Subject Headings (PhySH)Research AreasBranching fractionForm factorsLeptonic, semileptonic & radiative decaysParticle decaysPhysical SystemsCharm quarkParticles & Fields

The first observation of the decays J/ψ→p¯Σ+KS0 and J/ψ→pΣ¯−KS0 is reported using (10087±44)×106 J/ψ events recorded by the BESIII detector at the BEPCII storage ring. The branching fractions of each channel are determined to be B(J/ψ→p¯Σ+KS0)=(1.361±0.006±0.025)×10−4, and B(J/ψ→pΣ¯−KS0)=(1.352±0.006±0.025)×10−4. The combined result is B(J/ψ→p¯Σ+KS0+c.c.)=(2.725±0.009±0.050)×10−4, where the first uncertainty is statistical and the second systematic. The results presented are in good agreement with the branching fractions of the isospin partner decay J/ψ→pK−Σ¯0+c.c.Received 14 November 2023Accepted 14 December 2023DOI:https://doi.org/10.1103/PhysRevD.109.012006Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP3.Published by the American Physical SocietyPhysics Subject Headings (PhySH)Research AreasParticle interactionsStrong interactionPhysical SystemsBaryonsHyperonsTechniquesParticle data analysisParticles & Fields

Based on 4.4 fb−1 of e+e− annihilation data collected at the center-of-mass energies between 4.60 and 4.70 GeV with the BESIII detector at the BEPCII collider, the pure W-boson-exchange decay Λc+→Ξ0K+ is studied with a full angular analysis. The corresponding decay asymmetry is measured for the first time to be αΞ0K+=0.01±0.16(stat)±0.03(syst). This result reflects the noninterference effect between the S- and P-wave amplitudes. The phase shift between S- and P-wave amplitudes has two solutions, which are δp−δs=−1.55±0.25(stat)±0.05(syst) rad or 1.59±0.25(stat)±0.05(syst) rad.Received 6 September 2023Accepted 30 November 2023DOI:https://doi.org/10.1103/PhysRevLett.132.031801Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP3.Published by the American Physical SocietyPhysics Subject Headings (PhySH)Research AreasElectroweak interactionHadronic decaysPolarization in interactions & scatteringPhysical SystemsHyperonsW & Z bosonsParticles & Fields

Based on a data sample of (2712.4±14.3)×106ψ(3686) events collected with the BESIII detector at the BEPCII collider, the M1 transition ψ(3686)→γηc(2S) with ηc(2S)→KK¯π is studied, where KK¯π is K+K−π0 or KS0K±π∓. The mass and width of the ηc(2S) are measured to be (3637.8±0.8(stat)±0.2(syst)) MeV/c2 and (10.5±1.7(stat)±3.5(syst)) MeV, respectively. The product branching fraction B(ψ(3686)→γηc(2S))×B(ηc(2S)→KK¯π) is determined to be (0.97±0.06(stat)±0.09(syst))×10−5. Using B(ηc(2S)→KK¯π)=(1.86−0.49+0.68)%, we obtain the branching fraction of the radiative transition to be B(ψ(3686)→γηc(2S))=(5.2±0.3(stat)±0.5(syst)−1.4+1.9(extr))×10−4, where the third uncertainty is due to the quoted B(ηc(2S)→KK¯π).Received 26 September 2023Accepted 8 January 2024DOI:https://doi.org/10.1103/PhysRevD.109.032004Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP3.Published by the American Physical SocietyPhysics Subject Headings (PhySH)Research AreasBranching fractionLeptonic, semileptonic & radiative decaysQuark modelPhysical SystemsQuarkoniaParticles & Fields

By analyzing 7.33 fb−1 of e+e− annihilation data collected at center-of-mass energies between 4.128 and 4.226 GeV with the BESIII detector, we report the observation of the semileptonic decay Ds+→η′μ+νμ, with a statistical significance larger than 10σ, and the measurements of the Ds+→ημ+νμ and Ds+→η′μ+νμ decay dynamics for the first time. The branching fractions of Ds+→ημ+νμ and Ds+→η′μ+νμ are determined to be (2.235±0.051stat±0.052syst)% and (0.801±0.055stat±0.028syst)%, respectively, with precision improved by factors of 6.0 and 6.6 compared to the previous best measurements. Combined with the results for the decays Ds+→ηe+νe and Ds+→η′e+νe, the ratios of the decay widths are examined both inclusively and in several ℓ+νℓ four-momentum transfer ranges. No evidence for lepton flavor universality violation is found within the current statistics. The products of the hadronic form factors f+,0η(′)(0) and the c→s Cabibbo-Kobayashi-Maskawa matrix element |Vcs| are determined. The results based on the two-parameter series expansion are f+,0η(0)|Vcs|=0.452±0.010stat±0.007syst and f+,0η′(0)|Vcs|=0.504±0.037stat±0.012syst, which help to constrain present models on f+,0η(′)(0). The forward-backward asymmetries are determined to be ⟨AFBη⟩=−0.059±0.031stat±0.005syst and ⟨AFBη′⟩=−0.064±0.079stat±0.006syst for the first time, which are consistent with the theoretical calculation.Received 25 July 2023Revised 25 January 2024Accepted 26 January 2024DOI:https://doi.org/10.1103/PhysRevLett.132.091802Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP3.Published by the American Physical SocietyPhysics Subject Headings (PhySH)Research AreasBranching fractionLeptonic, semileptonic & radiative decaysParticle interactionsQuark mixingPhysical SystemsCharmed mesonsPropertiesFlavor symmetriesForm factorsParticles & Fields

Acute lung injury (ALI) is an acute multifactorial infectious disease caused by trauma, pneumonia, shock and sepsis. Paeoniae Radix Rubra (Paeonia lactiflora Pall. or Paeonia veitchii Lynch, Chishao in Chinese, CS) and Salviae Miltiorrhizae Radix et Rhizoma (Salvia miltiorrhiza Bge., Lamiaceae, Danshen in Chinese, DS) are common traditional Chinese medicines (TCMs). CS-DS herb pair has been widely used to promote blood circulation and eliminate blood stasis in Chinese clinical practice, appearing in a variety of prescriptions. However, it is still unclear for the effect and active ingredients of the herb pair on ALI.The study investigated the effect and active ingredients of CS-DS herb pair and demonstrated the synergistic effect and mechanisms of the active ingredients.Lipopolysaccharides (LPS)-stimulated RAW264.7 macrophage cells and BALB/c mice were used to establish an ALI model to investigate the effect of CS-DS herb pair on ALI. Network pharmacology and molecular docking were used to analyze the active ingredients and potential mechanisms of the herb pair. The synergistic effects and mechanisms of active ingredients on ALI were validated by in vitro and in vivo experiments.CS-DS herb pair had a synergistic effect on LPS-induced ALI. Based on the network pharmacology, the compounds paeoniflorin and luteolin were screened. Both paeoniflorin and luteolin had good affinity for NF-κB and MAPK by molecular docking. LPS stimulation of RAW264.7 cells resulted in a significant increase in ROS, NO, TNF-α, IL-6 and IL-1β, while the paeoniflorin combined with luteolin significantly reduced their expressions. In the LPS-induced ALI model, the combination also reduced the expression of inflammatory factors and oxidative stress levels. Furthermore, LPS activated the NF-κB and MAPK signaling pathways, whereas the combination decreased the expression of proteins in both pathways.CS-DS herb pair alleviated LPS-induced ALI with the active ingredients paeoniflorin and luteolin, which suppressed inflammation and oxidative stress via regulation of NF-κB and MAPK signaling pathways.

We perform for the first time an amplitude analysis of the decay D^{+}→K_{S}^{0}π^{+}η and report the observation of the decay D^{+}→K_{S}^{0}a_{0}(980)^{+} using 2.93 fb^{-1} of e^{+}e^{-} collision data taken at a center-of-mass energy of 3.773 GeV with the BESIII detector. As the only W-annihilation-free decay among D to a_{0}(980) pseudoscalar, D^{+}→K_{S}^{0}a_{0}(980)^{+} is the ideal decay in extracting the contributions of the W-emission amplitudes involving a_{0}(980) and to study the final-state interactions. The absolute branching fraction of D^{+}→K_{S}^{0}π^{+}η is measured to be (1.27±0.04_{stat}±0.03_{syst})%. The branching fractions of intermediate processes D^{+}→K_{S}^{0}a_{0}(980)^{+} with a_{0}(980)^{+}→π^{+}η and D^{+}→π^{+}K[over ¯]_{0}^{*}(1430)^{0} with K[over ¯]_{0}^{*}(1430)^{0}→K_{S}^{0}η are measured to be (1.33±0.05_{stat}±0.04_{syst})% and (0.14±0.03_{stat}±0.01_{syst})%, respectively.

Using a sample of (10087±44)×10^{6} J/ψ events, which is about 45 times larger than that was previously analyzed, a further investigation on the J/ψ→γ3(π^{+}π^{-}) decay is performed. A significant distortion at 1.84 GeV/c^{2} in the line shape of the 3(π^{+}π^{-}) invariant mass spectrum is observed for the first time, which could be resolved by two overlapping resonant structures, X(1840) and X(1880). The new state X(1880) is observed with a statistical significance larger than 10σ. The mass and width of X(1880) are determined to be 1882.1±1.7±0.7 MeV/c^{2} and 30.7±5.5±2.4 MeV, respectively, which indicates the existence of a pp[over ¯] bound state.

We report the observation of the decay mode ${B}^{\ifmmode\pm\else\textpm\fi{}}\ensuremath{\rightarrow}p\overline{p}{K}^{\ifmmode\pm\else\textpm\fi{}}$ based on an analysis of $29.4{\mathrm{fb}}^{\ensuremath{-}1}$ of data collected by the Belle detector at KEKB. This is the first example of a $b\ensuremath{\rightarrow}s$ transition with baryons in the final state. The $p\overline{p}$ mass spectrum in this decay is inconsistent with phase space and is peaked at low mass. The branching fraction for this decay is measured to be $B({B}^{\ifmmode\pm\else\textpm\fi{}}\ensuremath{\rightarrow}p\overline{p}{K}^{\ifmmode\pm\else\textpm\fi{}})\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}[{4.3}_{\ensuremath{-}0.9}^{+1.1}(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.5(\mathrm{syst})]\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}$. We also report upper limits for the decays ${B}^{0}\ensuremath{\rightarrow}p\overline{p}{K}_{S}$ and ${B}^{\ifmmode\pm\else\textpm\fi{}}\ensuremath{\rightarrow}p\overline{p}{\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}$.

The B meson decay modes B --> D p pbar and B --> D* p pbar have been studied using 29.4 fb^{-1} of data collected with the Belle detector at KEKB. The B0bar --> D0 p pbar and B0bar --> D*0 p pbar decays have been observed for the first time with branching fractions Br(B0bar --> D0 p pbar) =(1.18\pm 0.15\pm 0.16) 10^{-4} and Br(B0bar --> D*0 p pbar) =(1.20^{+0.33}_{-0.29}\pm 0.21) 10^{-4}. No signal has been found for the B+ --> D+ p pbar and B+ --> D*+ p pbar decay modes, and the corresponding upper limits at 90% C.L. are presented.

First results on inclusive $$\mathop {D^0 }\limits^{( - )} $$ andD*± production in neutral current deep inelasticep scattering are reported using data collected by the H1 experiment at HERA in 1994. Differential cross sections are presented for both channels and are found to agree well with QCD predictions based on the boson gluon fusion process. A charm production cross section for 10 GeV2≤Q2≤100 GeV2 and 0.01≤y≤0.7 of $$\sigma (ep \to ec\bar cX) = (17.4 \pm 1.6 \pm 1.7 \pm 1.4) nb$$ is derived. A first measurement of the charm contribution $$F_2^{c\bar c} (x,Q^2 )$$ to the proton structure function for Bjorkenx between 8·10−4 and 8·10−3 is presented. In this kinematic range a ratio $$F_2^{c\bar c} /F_2 = 0.237 \pm 0.021 \pm 0.041$$ is observed.

The results of a measurement of the proton structure function F2(x,Q2) and the virtual photon-proton cross section are reported for momentum transfers squared Q2 between 0.35 GeV2 and 3.5 GeV2 and for Bjorken-x values down to 6 × 10−6 using data collected by the HERA experiment H1 in 1995. The data represent an increase in kinematic reach to lower x and Q2 values of about a factor of 5 compared to previous H1 measurements. Including measurements from fixed target experiments the rise of F2 with decreasing x is found to be less steep for the lowest Q2 values measured. Phenomenological models at low Q2 are compared with the data.

We report the first observation of the charmless vector-vector decay process B∓→ρ∓ρ0. The measurement uses a 78 fb−1 data sample collected with the Belle detector at the KEKB asymmetric e+e− collider operating at the Υ(4S) resonance. We obtain a branching fraction of B(B∓→ρ∓ρ0)=[31.7±7.1(stat)−6.7+3.8(syst)]×10−6. An analysis of the ρ helicity-angle distributions gives a longitudinal polarization fraction of ΓL/Γ=0.95±0.11(stat)±0.02(syst). We also measure the direct-CP-violating asymmetry ACP(B∓→ρ∓ρ0)=0.00±0.22(stat)±0.03(syst).Received 3 June 2003DOI:https://doi.org/10.1103/PhysRevLett.91.221801©2003 American Physical Society

We report measurements of the radiative decay B → K * γ.The analysis is based on a data sample containing 85.0 × 10 6 B meson pairs collected by the Belle detector at the KEKB storage ring.We measure branching fractions of B(B 0 → K * 0 γ) = (4.01 ± 0.21 ± 0.17) × 10 -5 and B(B + → K * + γ) = (4.25 ± 0.31 ± 0.24) × 10 -5 , where the first and second errors are statistical and systematic, respectively.The isospin asymmetry between B 0 and B + decay widths is measured to be ∆0+ = +0.012± 0.044 ± 0.026.We search for a partial rate asymmetry between CP conjugate modes, and find ACP (B → K * γ) = -0.015± 0.044 ± 0.012.

Using a sample of 58 million J/ψ events recorded in the BESII detector, the decay J/ψ→ωπ+π− is studied. There are conspicuous ωf2(1270) and b1(1235)π signals. At low ππ mass, a large, broad peak due to the σ is observed, and its pole position is determined to be (541±39)−i(252±42)MeV from the mean of six analyses. The errors, which are dominated by the systematic errors, cover the statistical and systematic errors in the six analyses, as well as the observed variation of the six analyses.

We have performed a search for the lepton-flavor-violating decay tau -> mu gamma using a data sample of 86.3fb^{-1} accumulated by the Belle detector at KEK. No evidence for a signal is seen, and we set an upper limit for the branching fraction of B(tau -> mu gamma) < 3.1 x 10^{-7} at the 90% confidence level.

An enhancement near threshold is observed in the \omega \phi invariant mass spectrum from the doubly OZI suppressed decays of J/\psi \to \gamma \omega \phi, based on a sample of 5.8 X 10^7 J/\psi events collected with the BESII detector. A partial wave analysis shows that this enhancement favors J^P = 0^+, and its mass and width are M = 1812^{+19}_{-26} (stat) +- 18 (syst) MeV/c^2 and \Gamma = 105+-20 (stat) +- 28$ (syst) MeV/c^2. The product branching fraction is determined to be B(J/\psi\to \gamma X) B(X\to\omega\phi) = (2.61 +- 0.27 (stat) +- 0.65$ (syst)) X 10^{-4}.

Using the BES-II detector at the BEPC Collider, we measured the lowest order cross sections and the R values (R=σe+e−→hadrons0/σe+e−→μ+μ−0) for inclusive hadronic event production at the center-of-mass energies of 3.650, 3.6648 and 3.773 GeV. The results lead to R¯uds=2.218±0.019±0.089 which is the average of these measured at 3.650 GeV and 3.6648 GeV, and R=3.746±0.037±0.187 at s=3.773GeV. We determined the lowest order cross section for ψ(3770) production to be σψ(3770)B=(9.323±0.253±0.801)nb at 3.773 GeV, the branching fractions for ψ(3770) decays to be BF(ψ(3770)→D0D¯0)=(49.5±1.3±3.8)%, BF(ψ(3770)→D+D−)=(35.7±1.1±3.4)% and BF(ψ(3770)→DD¯)=(85.5±1.7±5.8)%, which result in the total non-DD¯ branching fraction of ψ(3770) decay to be BF(ψ(3770)→non-DD¯)=(14.5±1.7±5.8)%.

We present an improved measurement of CP-violation parameters in B0-->phiK(0)(S), K(+)K(-)K(0)(S), and eta(')K(0)(S) decays based on a 140 fb(-1) data sample collected at the Upsilon(4S) resonance with the Belle detector at the KEKB energy-asymmetric e(+)e(-) collider. One neutral B meson is fully reconstructed in one of the specified decay channels, and the flavor of the accompanying B meson is identified from its decay products. CP-violation parameters for each of the three modes are obtained from the asymmetries in the distributions of the proper-time intervals between the two B decays. We find that the observed CP asymmetry in the B-->phiK(0)(S) decay differs from the standard model (SM) expectation by 3.5 standard deviations, while the other cases are consistent with the SM.

We measure the branching fractions for $\ensuremath{\psi}(3770)\ensuremath{\rightarrow}{D}^{0}{\overline{D}}^{0}$, ${D}^{+}{D}^{\ensuremath{-}}$, $D\overline{D}$, and non-$D\overline{D}$ to be $(46.7\ifmmode\pm\else\textpm\fi{}4.7\ifmmode\pm\else\textpm\fi{}2.3)%$, $(36.9\ifmmode\pm\else\textpm\fi{}3.7\ifmmode\pm\else\textpm\fi{}2.8)%$, $(83.6\ifmmode\pm\else\textpm\fi{}7.3\ifmmode\pm\else\textpm\fi{}4.2)%$, and $(16.4\ifmmode\pm\else\textpm\fi{}7.3\ifmmode\pm\else\textpm\fi{}4.2)%$, respectively. The resonance parameters of $\ensuremath{\psi}(3770)$ and $\ensuremath{\psi}(2S)$ are measured to be ${M}_{\ensuremath{\psi}(3770)}=3772.2\ifmmode\pm\else\textpm\fi{}0.7\ifmmode\pm\else\textpm\fi{}0.3\text{ }\text{ }\mathrm{MeV}$, ${\ensuremath{\Gamma}}_{\ensuremath{\psi}(3770)}^{\mathrm{tot}}=26.9\ifmmode\pm\else\textpm\fi{}2.4\ifmmode\pm\else\textpm\fi{}0.3\text{ }\text{ }\mathrm{MeV}$, and ${\ensuremath{\Gamma}}_{\ensuremath{\psi}(3770)}^{ee}=251\ifmmode\pm\else\textpm\fi{}26\ifmmode\pm\else\textpm\fi{}11\text{ }\text{ }\mathrm{eV}$; ${M}_{\ensuremath{\psi}(2S)}=3685.5\ifmmode\pm\else\textpm\fi{}0.0\ifmmode\pm\else\textpm\fi{}0.3\text{ }\text{ }\mathrm{MeV}$, ${\ensuremath{\Gamma}}_{\ensuremath{\psi}(2S)}^{\mathrm{tot}}=331\ifmmode\pm\else\textpm\fi{}58\ifmmode\pm\else\textpm\fi{}2\text{ }\text{ }\mathrm{keV}$, and ${\ensuremath{\Gamma}}_{\ensuremath{\psi}(2S)}^{ee}=2.330\ifmmode\pm\else\textpm\fi{}0.036\ifmmode\pm\else\textpm\fi{}0.110\text{ }\text{ }\mathrm{keV}$. We also measure the light hadron $R$ value to be ${R}_{\mathrm{uds}}=2.262\ifmmode\pm\else\textpm\fi{}0.054\ifmmode\pm\else\textpm\fi{}0.109$ in the energy region from 3.660 to 3.872 GeV.

We present a precise measurement of the standard model $CP$-violation parameter $\mathrm{sin}2{\ensuremath{\phi}}_{1}$, the direct $CP$ violation parameter $|\ensuremath{\lambda}|$, the lifetimes of charged and neutral $B$ mesons and their ratio, and the ${B}^{0}$-${\overline{B}}^{0}$ mixing parameter $\ensuremath{\Delta}{m}_{d}$ based on a sample of $152\ifmmode\times\else\texttimes\fi{}{10}^{6}$ $B\overline{B}$ pairs collected at the $\ensuremath{\Upsilon}(4S)$ resonance with the Belle detector at the KEKB asymmetric-energy ${e}^{+}{e}^{\ensuremath{-}}$ collider. One of two $B$ mesons is fully reconstructed in a $CP$-eigenstate or a flavor-eigenstate decay channel. The flavor of the accompanying $B$ meson is identified from its decay products. From the distributions of the time interval between the two $B$ meson decay points, we obtain $\mathrm{sin}2{\ensuremath{\phi}}_{1}=0.728\ifmmode\pm\else\textpm\fi{}0.056(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.023(\mathrm{syst})$, $|\ensuremath{\lambda}|=1.007\ifmmode\pm\else\textpm\fi{}0.041(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.033(\mathrm{syst})$, ${\ensuremath{\tau}}_{{B}^{0}}=[1.534\ifmmode\pm\else\textpm\fi{}0.008(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.010(\mathrm{syst})]\text{ }\text{ }\mathrm{ps}$, ${\ensuremath{\tau}}_{{B}^{+}}=[1.635\ifmmode\pm\else\textpm\fi{}0.011(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.011(\mathrm{syst})]\text{ }\text{ }\mathrm{ps}$, ${\ensuremath{\tau}}_{{B}^{+}}/{\ensuremath{\tau}}_{{B}^{0}}=1.066\ifmmode\pm\else\textpm\fi{}0.008(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.008(\mathrm{syst})$ and $\ensuremath{\Delta}{m}_{d}=[0.511\ifmmode\pm\else\textpm\fi{}0.005(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.006{(\mathrm{syst})]\text{ }\text{ }\mathrm{ps}}^{\ensuremath{-}1}$. The results for $\mathrm{sin}2{\ensuremath{\phi}}_{1}$ and $|\ensuremath{\lambda}|$ are consistent with the standard model expectations. The significance of the observed deviation from unity in the lifetime ratio exceeds 5 standard deviations.

Using a data sample with a total integrated luminosity of 10.0 pb−1 collected at center-of-mass energies of 2.6, 3.07 and 3.65 GeV with BESII, cross sections for e+e− annihilation into hadronic final states (R values) are measured with statistical errors that are smaller than 1%, and systematic errors that are about 3.5%. The running strong interaction coupling constants αs(3)(s) and αs(5)(MZ2) are determined from the R values.

The cross section for e + e -→ ηJ/ψ between √ s = 3.8 GeV and 5.3 GeV is measured via initial state radiation using 980 fb -1 of data on and around the Υ(nS)(n = 1, 2, 3, 4, 5) resonances collected with the Belle detector at KEKB.Two resonant structures at the ψ(4040) and ψ(4160) are observed in the ηJ/ψ invariant mass distribution.Fitting the mass spectrum with the coherent sum of two Breit-Wigner functions, one obtains B(ψ(4040) → ηJ/ψ) • Γ ψ(4040) e + e - = (4.8± 0.9 ± 1.4) eV and B(ψ(4160) → ηJ/ψ) • Γ ψ(4160) e + e - = (4.0 ± 0.8 ± 1.4) eV for one solution and B(ψ(4040) → ηJ/ψ) • Γ ψ(4040) e + e - = (11.2± 1.3 ± 1.9) eV and B(ψ(4160) → ηJ/ψ) • Γ ψ(4160)e + e - = (13.8± 1.3 ± 2.0) eV for the other solution, where the first errors are statistical and the second are systematic.This is the first measurement of this hadronic transition mode of these two states, and the partial widths to ηJ/ψ are found to be about 1 MeV.There is no evidence for the Y (4260), Y (4360), ψ(4415), or Y (4660) in the ηJ/ψ final state, and upper limits of their production rates in e + e -annihilation are determined.