The decay D+-> K-S(0)pi(+)pi(+)pi(-) is studied with an amplitude analysis using a data set of 2.93 fb(-1) of e(+)e(-) collisions at the psi(3770) peak accumulated by the BESIII detector. Intermediate states and nonresonant components, and their relative fractions and phases, have been determined. The significant amplitudes, which contribute to the model that best fits the data, are composed of five quasitwo-body decays K(S)(0)a(1)(1260)(+), (K) over bar (1)(1270)(0)pi(+) (K) over bar (1)(1400)(0)pi(+), (K) over bar (1)(1650)(0)pi(+), and (K) over bar (1460)(0)pi(+), a three-body decay K-S(0)pi(+)rho(0), as well as a nonresonant component K-S(0)pi(+)pi(+)pi(-). The dominant amplitude is K(S)(0)a(1)(1260)(+), with a fit fraction of (40.3 +/- 2.1 +/- 2.9)%, where the first and second uncertainties are statistical and systematic, respectively.

The exclusive process e(+)e(-) -> Lambda(Lambda) over bar, with Lambda -> p pi(-) and (Lambda) over bar -> (p) over bar pi(+), has been studied at root s = 2.396 GeV for measurement of the timelike Lambda electric and magnetic form factors, G(E) and G(M). A data sample, corresponding to an integrated luminosity of 66.9 pb(-1), was collected with the BESIII detector for this purpose. A multidimensional analysis with a complete decomposition of the spin structure of the reaction enables a determination of the modulus of the ratio R = vertical bar G(E)/G(M)vertical bar and, for the first time for any baryon, the relative phase Delta Phi = Phi(E) - Phi(M). The resulting values are R = 0.96 +/- 0.14(stat) +/- 0.02(syst) and Phi(F) = 37 degrees +/- 12 degrees (stat) +/- 6 degrees (syst), respectively. These are obtained using the recently established and most precise value of the asymmetry parameter alpha(Lambda) = 0.750 +/- 0.010 measured by BESIII. In addition, the cross section is measured with unprecedented precision to be sigma = 118.7 +/- 5.3(stat) +/- 5.1(syst) pb, which corresponds to an effective form factor of vertical bar G vertical bar = 0.123 +/- 0.003(stat) +/- 0.003(syst). The contribution from two-photon exchange is found to be negligible. Our result enables the first complete determination of baryon timelike electromagnetic form factors.

The cross section of the process e(+)e(-) -> omega chi(C0) is measured at center -of -mass energies from root 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 root s shows a resonant structure with mass of (4218.5 +/- 1.6(stat) +/- 4.0(syst)) MeV/c(2) and width of (28.2 +/- 3.9(stat) +/- 1.6(syst)) MeV, respectively. This observation confirms and improves upon the result of a previous study. The angular distribution of the e(+) e(-) ->omega chi(C0) process is extracted for the first time.

We measure the Born cross sections of the process e(+)e(-) -> K+ K- K+ K- at center-of-mass (c.m.) energies, root s, between 2.100 and 3.080 GeV. The data were collected using the BESIII detector at the BEPCII collider. An enhancement at root s = 2.232 GeV is observed, very close to the e(+)e(-) -> Lambda(Lambda) over bar production threshold. A similar enhancement at the same c.m. energy is observed in the e(+)e(-) -> phi K+ K- cross section. The energy dependence of the K+ K- K+ K- and phi K+ K- cross sections differs significantly from that of e(+)e(-) -> phi pi(+)pi(-).

Using E1 radiative transitions psi(3686) -> gamma chi(cJ) from a sample of (448.1 +/- 2.9) x 10(6) psi(3686) events collected with the BESIII detector, the decays chi(cJ) -> Sigma(+)(p) over barK(S)(0) + c.c.(J = 0,1,2) are studied. The decay branching fractions are measured to be B(chi(c0) -> Sigma(+)(p) over barK(S)(0) + c.c.) = (3.52 +/- 0.19 +/- 0.21) x 10(-4), B(chi(c1) -> Sigma(+)(p) over barK(S)(0) + c.c.) = (1.53 +/- 0.10 +/- 0.08) x 10(-4), and B(chi(c2) -> Sigma(+)(p) over barK(S)(0) + c.c.) = (8.25 +/- 0.83 +/- 0.49) x 10(-5), where the first and second uncertainties are the statistical and systematic ones, respectively. No evident intermediate resonances arc observed in the studied processes.

Based on (4.48 +/- 0.03) x 10(8) Psi(3686) events, collected with the BESIII detector at the BEPCII storage ring, five h(c) hadronic decays are searched for via the process Psi(3686) -> pi(0)h(c). Three of them, h(c) -> p (p) over bar pi(+)pi(-) , pi(+)pi(-)pi(0 )and 2(pi(+)pi(-))pi(0) are observed for the first time with significances of 7.4 sigma, 4.6 sigma, and 9.1 sigma, and their branching fractions are determined to be (2.89 +/- 0.32 +/- 0.55) x 10(-3), (1.60 +/- 0.40 +/- 0.32) x 10(-3), and (7.44 +/- 0.94 +/- 1.52) x 10(-3), respectively, where the first uncertainties are statistical and the second systematic. No significant signal is observed for the other two decay modes, and the corresponding upper limits of the branching fractions are determined to be B(h(c) -> 3(pi(+)pi(-))pi(0)) < 8.7 x 10(-3) and B(h(c) -> K+K-pi(+)pi(-) ) < 5.8 x 10(-4) at the 90% confidence level.

By analyzing 2.93 fb(-1) of e(+)e(-) annihilation data taken at the center-of-mass energy root s = 3.773 GeV with the BESIII detector, we determine the branching fractions of the inclusive decays D+-> phi X and D-0 -> phi X to be (1.135 +/- 0.034 +/- 0.031)% and (1.091 +/- 0.027 +/- 0.035)%, respectively, where X denotes any possible particle combination. The first uncertainties are statistical, and the second are systematic. We also determine the branching fractions of the decays D -> phi X and their charge conjugate modes (D) over bar -> phi(X) over bar separately for the first time, and no significant CP asymmetry is observed.

The four decay modes D-0 -> phi pi(0), D-0 -> phi eta, D+ -> phi pi(+), and D+ up arrow phi K+ are studied by using a data sample taken at the centre-of-mass energy root s = 3.773 GeVwith the BESIII detector, corresponding to an integrated luminosity of 2.93 fb(-1). The branching fractions of the first three decay modes are measured to be B(D-0 -> phi pi(0)) = (1.168 +/- 0.028 +/- 0.028) x 10(-3), B(D-0 -> phi eta) = (1.81 +/- 0.46 +/- 0.06) x 10(-4), and B(D+ -> phi pi(+)) = (5.70 +/- 0.05 +/- 0.13) x 10(-3), respectively, where the first uncertainties are statistical and the second are systematic. In addition, the upper limit of the branching fraction for D+ -> phi K+ is given to be 2.1 x 10(-5) at the 90% confidence level. The ratio of B(D-0 -> phi pi(0)) to B(D+ -> phi pi(+)) is calculated to be (20.49 +/- 0.50 +/- 0.45)%, which is consistent with the theoretical prediction based on isospin symmetry between these two decay modes. 

Using a sample of 448.1 x 10(6) psi(3686) events collected with the BESIII detector, we perform a study of the decay psi(3686) -> phi pi(+)pi(-)eta. The branching fraction of psi(3686) -> phi eta' is determined to be (1.51 +/- 0.16 +/- 0.12) x 10(-5), which is consistent with the previous measurement but with significantly improved precision. The resonances f(1)(1285) and eta(1405) are clearly observed in the pi(+)pi(-)eta mass spectrum with statistical significances of 18s and 9.7 sigma, respectively. The corresponding product branching fractions are measured to be B(psi(3686) -> phi f(1)(1285), f(1)(1285) -> pi(+)pi(-)eta) = )1.03 +/- 0.10 +/- 0.09) x 10(-5) and B(psi(3686) -> phi eta(1405), eta(1405) -> pi(+)pi(-)eta) = (8.46 +/- 1.37 +/- 0.92) x 10(-6). These results are used to test the perturbative QCD "12% rule."

Using a sample of 1.31 x 10(9) J/psi events collected by the BESIII detector at BEPCII during 2009 and 2012, we study the J/psi -> omega eta'pi(+)pi(-) thorn p-hadronic process. For the first time, we measure the branching ratio B(J/psi -> omega eta'pi(+)pi(-)) = (1.12 +/- 0.02 +/- 0.13) x 10(-3). We search for the X(1835) state in the eta'pi(+)pi(-) invariant mass spectra. No evidence is found and we estimate the upper limit on the branching fraction at 90% confidence level to be B(J/psi -> omega X(1835), X(1835) -> eta'pi(+)pi(-)) < 6.2 x 10(-5).