Multiplicities of charged hadrons produced in deep inelastic muon scattering off a 6LiD target have been measured as a function of the DIS variables xBj , Q2, W2 and the final state hadron variables pT and z. The p2T distributions are fitted with a single exponential function at low values of p2T to determine the dependence of 〈p2T 〉 on xBj , Q2, W2 and z. The z-dependence of 〈p2T 〉 is shown to be a potential tool to extract the average intrinsic transverse momentum squared of partons, 〈k2⊥〉, as a function of xBj and Q2 in a leading order QCD parton model.

We report a measurement of the branching fraction for ψ(3770)→γχc1 and search for the transition ψ(3770)→γχc2 based on 2.92 fb-1 of e+e- data accumulated at s=3.773 GeV with the BESIII detector at the BEPCII collider. We measure B(ψ(3770)→γχc1)=(2.48±0.15±0.23)×10-3, which is the most precise measurement to date. The upper limit on the branching fraction of ψ(3770)→γχc2 at a 90% confidence level is B(ψ(3770)→γχc2)<0.64×10-3. The corresponding partial widths are Γ(ψ(3770)→γχc1)=(67.5±4.1±6.7) keV and Γ(ψ(3770)→γχc2)<17.4 keV.

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.

We study the decays of the charmonium resonances J/ψ and ψ(3686) to the final states Ξ-Ξ+, Σ(1385) Σ(1385)± based on a single baryon tag method using data samples of (223.7±1.4)×106 J/ψ and (106.4±0.9)×106 ψ(3686) events collected with the BESIII detector at the BEPCII collider. The decay ψ(3686)→Σ(1385) Σ(1385)± is observed for the first time, and the measurements of the other processes, including the branching fractions and angular distributions, are in good agreement with, and much more precise than, the previously published results. Additionally, the ratios B(ψ(3686)→Ξ-Ξ+)B(J/ψ→Ξ-Ξ+), B(ψ(3686)→Σ(1385)-Σ(1385)+)B(J/ψ→Σ(1385)-Σ(1385)+) and B(ψ(3686)→Σ(1385)+Σ(1385)-)B(J/ψ→Σ(1385)+Σ(1385)-) are determined.

Using 2.92 fb-1 of electron-positron annihilation data collected at √s = 3.773 GeV with the BESIII detector, we report the results of a search for the flavor-changing neutral current process D0 →γγ using a double-tag technique. We find no signal and set an upper limit at 90% confidence level for the branching fraction of B(D0 →γγ)< 3.8 × 10-6. We also investigate D0-meson decay into two neutral pions, obtaining a branching fraction of B(D0 →π0π0)= (8.24 ± 0.21(stat) ± 0.30(syst)) × 10-4, the most precise measurement to date and consistent with the current world average.

Using 1.06 × 108ψ (3686) events recorded in e+e-, collisions at √s = 3.686 GeV with the BESIII at the BEPCII collider, we present searches for C-parity violation in J/ψ → γγ and γφ decays via ψ(3686) → J/ψπ+π-. No significant signals are observed in either channel. Upper limits on the branching fractions are set to be B(J/ψ → γγ) < 2.7 × 10-7, and B(J/ψ → γφ>) < 1.4 × 10-6, at the 90% confidence level. The former is one order of magnitude more stringent than the previous upper limit, and the latter represents the first limit on this decay channel.

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 present the first search for the rare decay of η′ into K±π in J/ψ→φη′, using a sample of 1.3×109 J/ψ events collected with the BESIII detector. No significant signal is observed, and the upper limit at the 90% confidence level for the ratio B(η′→K±π)B(η′→γπ+π-) is determined to be 1.3×10-4. In addition, we report the measurement of the branching fraction of J/ψ→φη′ to be [5.10±0.03(stat)±0.32(syst)]×10-4, which agrees with previous results from BESII.

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 ¯]^{*}.