Using e+e annihilation data taken at the CESR collider with the CLEO-c detector, measurements of hyperon pair production cross sections and elastic and transition electromagnetic form factors have been made at the charmonium resonances: 0(2S), 3.69 GeV, 1Q21 = 13.6 GeV2,,C = 48 pb-1; 0(3770), \/7s = 3.77 GeV, 1Q21 = 14.2 GeV2, = 805 pb-1; and 0(4170), \/7s = 4.17 GeV, 1Q21 = 17.4 GeV2, G = 586 pb-1. Results with good statistical precision are obtained with high efficiency particle identification. Systematics of pair production cross sections, and form factors with respect to the number of strange quarks in the hyperons are studied, and evidence is presented for effects of diquark correlations in comparative results for A and E, both of which have the same uds quark content but different isospin.

Using e(+)e(-) annihilation data taken with the CLEO-c detector, measurements of two major Obranching fractions have been made using the reaction psi(2S) -> Omega(-)(Omega) over bar (+) . The Omega(-) decay channels are identified through momentum distributions of charged particles, and systematics of the Omega(-) branching fractions have been studied. The results are B(Omega(-) -> Lambda(0) K-) = (68.9 +/- 9.5 +/- 4.3)% and B(Omega(-) -> Xi pi(-0)) = (19.0 +/- 4.0 +/- 1.2)%.

The presentation has two parts, the first, and main part, is devoted to the presentation of results fromthe first measurements of the production of Λ, Σ Ξ and Ω hyperons at large timelike momentutransfers of 13.6, 14.2 and 17.4 GeV/c2 made using e+e− annihilation data taken at the CESER election-positron collider at Cornell using the CLEOc detector. The measurements reveal interesting features of hyperon production systematics and timelike form factors, and provide evidence for diquark correlations in hyperon structure. The second part of the presentation is devoted to measurements of photoproduction of J/ψ near threshold energies, EG = 8 − 12 GeV, at the new photon physics facility, GlueX, at the Jefferson Laboratory. The first preliminary results are presented. These are expected to shed light on the gluon structure of protons, gluons which mediate the production of J/ψ in the reaction,γp → J/ψ → e+e−.

We report on a precision measurement of the cross section for the reaction e(+)e(-) -> pi(+) pi(-) in the mass range 0.30 < M-pi pi < 1.00 GeV/c(2) with the initial state radiation (ISR) method, using 817 pb(-1) of data at e(+)e(-) center- of-mass energies near 3.77 GeV and 586 pb(-1) of data at e(+)e(-) center-of-mass energies near 4.17 GeV, collected with the CLEO-c detector at the CESR e(+)e(-) collider at Cornell University. The integrated cross sections in the range 0.30 < M-pi pi < 1.00 GeV/c(2) for the process e(+)e(-) -> pi(+) pi(-) are determined with a statistical uncertainty of 0.7% and a systematic uncertainty of 1.6%. The leading-order hadronic contribution to the muon anomalous magnetic moment calculated using these measured e(+)e(-) -> pi(+) pi(-) cross sections in the range M-pi pi = 0.30 to 1.00 GeV/c(2) is calculated to be (500.6 +/- 3.6(stat) +/- 8.0 (syst)) x 10(-10).

Using e(+)e(-) annihilation data taken with the CLEO-c detector at root s = 3770 MeV and 4170 MeV, we report the first measurements of the electromagnetic form factors of the Lambda(0), Sigma(0), Sigma(+), Xi(0), Xi(-), and Omega(-) hyperons for the large timelike momentum transfers of vertical bar Q(2)vertical bar = 14.2 GeV2 and 17.4 GeV2, respectively. The enhancement in Lambda(0) production over that of Sigma(0), both of which have the same uds quark content, gives evidence for significant diquark correlations in these hyperons. Improved measurements of the branching fractions of psi(2S) to hyperon-antihyperon pairs are also reported.

Using 53 pb−1 of e+e− annihilation data taken at the ψ(2S) resonance, a comprehensive study has been made of the radiative decays of samples of 5.1 million J/ψ and 24.5 million ψ(25) into pairs of pseudoscalar mesons, π+π−, π0π0, K+ K−, KS0KS0 and ηη. Product branching fractions for the radiative decays of J/ψ and ψ(2S) to scalar and tensor resonances have been determined, and are discussed in relation to predicted glueballs. For ψ(25) radiative decays, the search for glueballs has been extended to masses between 2.5 GeV and 3.3 GeV.

A precision measurement of the mass difference between the $D^0$ and $D^{*0}$ mesons has been made using 316~pb$^{-1}$ of $e^{+}e^{-}$ annihilation data taken at $\sqrt{s}=4170$~MeV using the CLEO-c detector. We obtain $\Delta M \equiv M(D^{*0})-M(D^0) =142.007\pm0.015$(stat)~$\pm$~0.014(syst)~MeV, as the average for the two decays, $D^0\to K^-\pi^+$ and $D^0\to K^-\pi^+\pi^-\pi^+$. The new measurement of $\Delta M$ leads to $M(D^{*0})=2006.850\pm0.049$~MeV, and the currently most precise measurement of the binding energy of the ``exotic'' meson X(3872) if interpreted as a $D^0D^{*0}$ hadronic molecule, $E_{b}(\text{X}(3872))\equiv M(D^0D^{*0})-M(\text{X}(3872))=3\pm192$ keV.

A precision measurement of the mass difference between the D-0 and D*(0) mesons has been made using 316 pb(-1) of e(+)e(-) annihilation data taken at root s = 4170 MeV using the CLEO-c detector. We obtain Delta M equivalent to M (D*(0)) - M(D-0) = 142.007 +/- 0.015(stat) +/- 0.014(syst) MeV, as the average for the two decays, D-0 -> K-pi(+) and D-0 -> K-pi(+)pi(-)pi(+). The new measurement of Delta M leads to M(D*(0)) = 2006.850 +/- 0.049 MeV, and the currently most precise measurement of the binding energy of the "exotic" meson X(3872) if interpreted as a (DD)-D-0*(0) hadronic molecule, E-b(X(3872)) equivalent to M((DD)-D-0*(0)) -M(X(3872)) = 3 +/- 192 keV.

A review of recent precision measurements of the electromagnetic form factors of the mesons, pion and kaon, and the hyperons, Λ0, Σ0, Σ+, Ξ−, Ξ0, Ω−, at large timelike momentum transfers is presented. Evidence is found for diquark correlations in Λ0, Σ0 hyperons.

Electromagnetic form factors of hadrons for timelike momentum transfers can be measured by particle-antiparticle annihilation into hadron-antihadron pairs. We have made the world’s first high precision measurements of timelike form factors of π and K mesons, and ground states of the baryons, protons, and the hyperons Λ0, Σ0, Σ+, Ξ0, Ξ–, Ω– at the high momentum transfers of 14.2 and 17.4 GeV2. Limitations of perturbative QCD are revealed, and evidence is presented for the effects of diquark correlations in Λ0 and Σ0.

Using 805 pb−1 of e+e− annihilation data taken with the CLEO-c detector at ψ(3770), s=3770 MeV, we report the first measurements of the electromagnetic form factors of the Λ0, Σ0, Σ+, Ξ0, Ξ−, and Ω− hyperons for the large timelike momentum transfer of |Q2|=14.2 GeV2. The form factors for the different hyperons are found to vary by nearly a factor two. It is found that |GM(Λ0)|=1.66(24)×|GM(Σ0)|. The Λ0 and Σ0 hyperons have the same uds quark content, but differ in their isospin, and therefore the spin of the ud quark pair. It is suggested that the spatial correlation implied by the singlet spin–isospin configuration in the Λ0 is an example of strong diquark correlations in the Λ0, as anticipated by Jaffe and Wilczek. Improved measurements of the branching fractions of ψ(2S)→pp¯ and hyperon–antihyperon pairs are also reported.

Updated measurements of absolute D+ and D0 hadronic branching fractions and σ(e+e⁻→DD¯) at Ecm=3774 MeV

Results of recent precision measurements of the electromagnetic form factors of the pion, kaon, proton, and the hyperons, Lambda(0), Sigma(0), Sigma(+), Xi(-), Xi(0), Omega(-), at large timelike momentum transfers are presented. Evidence is found for diquark correlations in Lambda(0), Sigma(0) hyperons.

At large momentum transfers the photon interacts with the charges and spins of the constituent partons in a hadron. It is expected that the neutral kaon can acquire finite electromagnetic form factors because its wave function is affected by the order of magnitude difference between the mass of the strange quark and that of the down quark, or flavor SU(3) breaking. We report on the first measurement of the form factor of neutral kaons at the large timelike momentum transfer of |Q(2)| = 17.4 GeV2 by measuring the cross section for e(+)e(-) -> KSKL at root s = 4.17 GeV using CLEO-c data with an integrated luminosity of 586 pb(-1). We obtain F-KSKL (17.4 GeV2) = 5.3 x 10(-3), with a 90% C.L. interval of (2.9-8.2) x 10(-3). This is nearly an order of magnitude smaller than FK+K-(17.4 GeV2) = (44 +/- 1) x 10(-3), and indicates that the effect of SU(3) breaking is small. In turn, this makes it unlikely that the recently observed strong violation of the pQCD prediction, F pi+pi-(|Q(2)|)/FK+K-(|Q(2)|) = f(pi)(2)/f(K)(2), which is based on the assumption of similar wave functions for the pions and kaons, can be attributed to SU(3) breaking alone. (C) 2014 Elsevier B.V.

Using 580 pb(-1) of e(+)e(-) annihilation data taken with the CLEO-c detector at psi(3770), the decay D-0 ((D) over bar (0)) -> K-+/-pi(-/+)pi(+)pi(-) has been studied to make the highest precision measurement of D-0 mass, M(D-0) 1864.845 +/- 0.025 +/- 0.022 +/- 0.053 MeV, where the first error is statistical, the second error is systematic, and the third error is due to uncertainty in kaon masses. As an intermediate step of the present investigation, the mass of the K-S meson has been measured to be M(K-S) = 497.607 +/- 0.007 +/- 0.015 MeV. Both M(D-0) and M(K-S) are the most precise single measurements of the masses of these mesons.

The electromagnetic structure of the lightest hadrons, proton, pion, and kaon is studied by high-precision measurements of their form factors for the highest timelike momentum transfers of |Q2|=s=14.2 and 17.4  GeV2. Data taken with the CLEO-c detector at sqrt[s]=3.772 and 4.170 GeV, with integrated luminosities of 805 and 586  pb(-1), respectively, have been used to study e+ e- annihilations into π+ π-, K+ K-, and pp. The dimensional counting rule prediction that at large Q2 the quantity Q2F(Q2) for pseudoscalar mesons is nearly constant, and should vary only weakly as the strong coupling constant αS(Q2) is confirmed for both pions and kaons. However, the measurements are in strong quantitative disagreement with the predictions of the existing quantum chromodynamics-based models. For protons, it is found that the timelike form factors continue to remain nearly twice as large as the corresponding spacelike form factors measured in electron elastic scattering, in significant violation of the expectation of their equality at large Q2. Further, in contrast to pions and kaons, a significant difference is observed between the values of the corresponding quantity |Q4|G(M)(|Q2|)/μ(p) for protons at |Q2|=14.2 and 17.4  GeV2. The results suggest the constancy of |Q2|G(M)(|Q2|)/μ(p), instead, at these large |Q2|.

A precision determination of the binding energy of the quintessential exotic meson X(3872) as a D0D*0¯ molecule has been made by means of a precision measurement of mass of D0 in its decay into three different modes, D0→KSφ, K±π∓π+π−, and KSπ+π−. We obtain M(D0) = 1864.770±0.024±0.077 MeV, and M(D0+D*0) = 3871.660±0.176 MeV. This leads to binding energy of B.E.(X(3872)) = M(D0+D*0)−M(X(3872)) = −0.012±0.248 MeV, using the current value of M(X(3872)) = 3871.672±0.174 MeV.

The ``exotic'' mesons $X(3872)$, $X(3915)$, $X(3930)$ and $X(3940)$, have been searched for in their radiative production in the $586\text{ }\text{ }{\mathrm{pb}}^{\ensuremath{-}1}$ ${e}^{+}{e}^{\ensuremath{-}}$ annihilation data taken with the CLEO-c detector at the $\ensuremath{\psi}(4160)$ resonance, and their decay in the two modes, $X\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}J/\ensuremath{\psi}$ and $X\ensuremath{\rightarrow}\ensuremath{\gamma}J/\ensuremath{\psi}$, with $J/\ensuremath{\psi}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$. No evidence for any of the four mesons is found. Upper limits for the product branching fractions, ${\mathcal{B}}_{1}(\ensuremath{\psi}(4160)\ensuremath{\rightarrow}\ensuremath{\gamma}X)\ifmmode\times\else\texttimes\fi{}{\mathcal{B}}_{2}(X\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}J/\ensuremath{\psi},\ensuremath{\gamma}J/\ensuremath{\psi})$ have been determined. The limits at 90% confidence level range from $0.7\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$ to $1.8\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$.

The "exotic" mesons X(3872), X(3915), X(3930) and X(3940), have been searched for in their radiative production in the 586 pb(-1) e(+)e(-) annihilation data taken with the CLEO-c detector at the psi(4160) resonance, and their decay in the two modes, X -> pi(+) pi(-) J/psi and X -> gamma J/psi, with J/psi -> mu(+)mu(-). No evidence for any of the four mesons is found. Upper limits for the product branching fractions, B-1(psi(4160) -> gamma X) X B-2(X -> pi(+)pi(-) J/psi, gamma J/psi) have been determined. The limits at 90% confidence level range from 0.7 X 10(-4) to 1.8 X 10(-4.)

Using 586 pb(-1) of e(+)e(-) annihilation data taken with the CLEO-c detector at root s = 4170 MeV, the peak of the charmonium resonance psi(4160), we analyze the decay psi(4160) -> pi(+)pi(-) J/psi, and report observation of the charged state Z(c)(+/-)(3900) decaying into pi(+/-) J/psi at a significance level of > 5 sigma. We obtain M(Z(c)(+/-)) = 3886 +/- 4(stat) +/- 2(syst) MeV and Gamma(Z(c)(+/-)) = 37 +/- 4(stat) +/- 8(syst) MeV, which are in good agreement with the results for this resonance obtained by the BES III and Belle Collaborations in the decay of the resonance Y(4260). We also present first evidence for the production of the neutral member of this isospin triplet, Z(c)(0)(3900) decaying into pi(0) J/psi at a 3.5 sigma significance level. (C) 2013 Elsevier B.V. All rights reserved.