Search for rare and forbidden decays of charm and charmed-strange mesons to final states h^+- e^-+ e^+

We have searched for flavor-changing neutral current decays and lepton-number-violating decays of D^+ and D^+_s mesons to final states of the form h^+- e^-+ e^+, where h is either \pi or K. We use the complete samples of CLEO-c open-charm data, corresponding to integrated luminosities of 818 pb^-1 at the center-of-mass energy E_CM = 3.774 GeV containing 2.4 x 10^6 D^+D^- pairs and 602 pb^-1 at E_CM = 4.170 GeV containing 0.6 x 10^6 D^*+-_s D^-+_s pairs. No signal is observed in any channel, and we obtain 90% confidence level upper limits on branching fractions B(D^+ --> \pi^+ e^+ e^-) < 5.9 x 10^-6, B(D^+ --> \pi^- e^+ e^+) K^+ e^+ e^-) < 3.0 x 10^-6, B(D^+ --> K^- e^+ e^+) \pi^+ e^+ e^-) < 2.2 x 10^-5, B(D^+_s --> \pi^- e^+ e^+) K^+ e^+ e^-) < 5.2 x 10^-5, and B(D^+_s --> K^- e^+ e^+) < 1.7 x 10^-5.Comment: 9 pages, available through http://www.lns.cornell.edu/public/CLNS

Determination of the D0 -> K+pi- Relative Strong Phase Using Quantum-Correlated Measurements in e+e- -> D0 D0bar at CLEO

We exploit the quantum coherence between pair-produced D0 and D0bar in psi(3770) decays to study charm mixing, which is characterized by the parameters x and y, and to make a first determination of the relative strong phase \delta between doubly Cabibbo-suppressed D0 -> K+pi- and Cabibbo-favored D0bar -> K+pi-. We analyze a sample of 1.0 million D0D0bar pairs from 281 pb^-1 of e+e- collision data collected with the CLEO-c detector at E_cm = 3.77 GeV. By combining CLEO-c measurements with branching fraction input and time-integrated measurements of R_M = (x^2+y^2)/2 and R_{WS} = Gamma(D0 -> K+pi-)/Gamma(D0bar -> K+pi-) from other experiments, we find \cos\delta = 1.03 +0.31-0.17 +- 0.06, where the uncertainties are statistical and systematic, respectively. In addition, by further including external measurements of charm mixing parameters, we obtain an alternate measurement of \cos\delta = 1.10 +- 0.35 +- 0.07, as well as x\sin\delta = (4.4 +2.7-1.8 +- 2.9) x 10^-3 and \delta = 22 +11-12 +9-11 degrees.Comment: 37 pages, also available through http://www.lns.cornell.edu/public/CLNS/2007/. Incorporated referee's comment

Updated Measurement of the Strong Phase in D0 --> K+pi- Decay Using Quantum Correlations in e+e- --> D0 D0bar at CLEO

We analyze a sample of 3 million quantum-correlated D0 D0bar pairs from 818 pb^-1 of e+e- collision data collected with the CLEO-c detector at E_cm = 3.77 GeV, to give an updated measurement of \cos\delta and a first determination of \sin\delta, where \delta is the relative strong phase between doubly Cabibbo-suppressed D0 --> K+pi- and Cabibbo-favored D0bar --> K+pi- decay amplitudes. With no inputs from other experiments, we find \cos\delta = 0.81 +0.22+0.07 -0.18-0.05, \sin\delta = -0.01 +- 0.41 +- 0.04, and |\delta| = 10 +28+13 -53-0 degrees. By including external measurements of mixing parameters, we find alternative values of \cos\delta = 1.15 +0.19+0.00 -0.17-0.08, \sin\delta = 0.56 +0.32+0.21 -0.31-0.20, and \delta = (18 +11-17) degrees. Our results can be used to improve the world average uncertainty on the mixing parameter y by approximately 10%.Comment: Minor revisions, version accepted by PR

Measurement of Charm Production Cross Sections in e+e- Annihilation at Energies between 3.97 and 4.26 GeV

Using the CLEO-c detector at the Cornell Electron Storage Ring, we have measured inclusive and exclusive cross sections for the production of D+, D0 and Ds+ mesons in e+e- annihilations at thirteen center-of-mass energies between 3.97 and 4.26 GeV. Exclusive cross sections are presented for final states consisting of two charm mesons (DD, D*D, D*D*, Ds+Ds-, Ds*+Ds-, and Ds*+Ds*-) and for processes in which the charm-meson pair is accompanied by a pion. No enhancement in any final state is observed at the energy of the Y(4260).Comment: 19 pages, postscript also available through http://www.lns.cornell.edu/public/CLNS/2007/, Submitted to PR

Heavy quarkonium: progress, puzzles, and opportunities

A golden age for heavy quarkonium physics dawned a decade ago, initiated by the confluence of exciting advances in quantum chromodynamics (QCD) and an explosion of related experimental activity. The early years of this period were chronicled in the Quarkonium Working Group (QWG) CERN Yellow Report (YR) in 2004, which presented a comprehensive review of the status of the field at that time and provided specific recommendations for further progress. However, the broad spectrum of subsequent breakthroughs, surprises, and continuing puzzles could only be partially anticipated. Since the release of the YR, the BESII program concluded only to give birth to BESIII; the $B$-factories and CLEO-c flourished; quarkonium production and polarization measurements at HERA and the Tevatron matured; and heavy-ion collisions at RHIC have opened a window on the deconfinement regime. All these experiments leave legacies of quality, precision, and unsolved mysteries for quarkonium physics, and therefore beg for continuing investigations. The plethora of newly-found quarkonium-like states unleashed a flood of theoretical investigations into new forms of matter such as quark-gluon hybrids, mesonic molecules, and tetraquarks. Measurements of the spectroscopy, decays, production, and in-medium behavior of c\bar{c}, b\bar{b}, and b\bar{c} bound states have been shown to validate some theoretical approaches to QCD and highlight lack of quantitative success for others. The intriguing details of quarkonium suppression in heavy-ion collisions that have emerged from RHIC have elevated the importance of separating hot- and cold-nuclear-matter effects in quark-gluon plasma studies. This review systematically addresses all these matters and concludes by prioritizing directions for ongoing and future efforts.Comment: 182 pages, 112 figures. Editors: N. Brambilla, S. Eidelman, B. K. Heltsley, R. Vogt. Section Coordinators: G. T. Bodwin, E. Eichten, A. D. Frawley, A. B. Meyer, R. E. Mitchell, V. Papadimitriou, P. Petreczky, A. A. Petrov, P. Robbe, A. Vair

Data S1: Dataset of Shigella

In social animals, group living may impact the risk of infectious disease acquisition in two ways. On the one hand, social connectedness puts individuals at greater risk or susceptibility for acquiring enteric pathogens via contact-mediated transmission. Yet conversely, in strongly bonded societies like humans and some nonhuman primates, having close connections and strong social ties of support can also socially buffer individuals against susceptibility or transmissibility of infectious agents. Using social network analyses, we assessed the potentially competing roles of contact-mediated transmission and social buffering on the risk of infection from an enteric bacterial pathogen (Shigella flexneri) among captive groups of rhesus macaques (Macaca mulatta). Our results indicate that, within two macaque groups, individuals possessing more direct and especially indirect connections in their grooming and huddling social networks were less susceptible to infection. These results are in sharp contrast to several previous studies that indicate that increased (direct) contact-mediated transmission facilitates infectious disease transmission, including our own findings in a third macaque group in which individuals central in their huddling network and/or which initiated more fights were more likely to be infected. In summary, our findings reveal that an individual’s social connections may increase or decrease its chances of acquiring infectious agents. They extend the applicability of the social buffering hypothesis, beyond just stress and immune-function-related health benefits, to the additional health outcome of infectious disease resistance. Finally, we speculate that the circumstances under which social buffering versus contact-mediated transmission may occur could depend on multiple factors, such as living condition, pathogen-specific transmission routes, and/or an overall social context such as a group’s social stability

Updated measurements of absolute D+D^+ and D0D^0 hadronic branching fractions and σ(e+e−→DD‾)\sigma(e^+e^-\to D\overline{D}) at Ecm=3774E_\mathrm{cm} = 3774 MeV

Utilizing the full CLEO-c data sample of 818 pb$^{-1}$ of $e^+e^-$ data taken at the $\psi(3770)$ resonance, we update our measurements of absolute hadronic branching fractions of charged and neutral $D$ mesons. We previously reportedresults from subsets of these data. Using a double tag technique we obtain branching fractions for three $D^0$ and six $D^+$ modes, including the reference branching fractions $\mathcal{B} (D^0\to K^-\pi^+)=(3.934 \pm 0.021 \pm 0.061)\%$ and $\mathcal{B} (D^+ \to K^- \pi^+\pi^+)=(9.224 \pm 0.059 \pm 0.157)\%$. The uncertainties are statistical and systematic, respectively. In these measurements we include the effects of final-state radiation by allowing for additional unobserved photons in the final state, and the systematic errors include our estimates of the uncertainties of these effects. Furthermore, using an independent measurement of the luminosity, we obtain the cross sections $\sigma(e^+e^-\to D^0\overline{D}{}^0)=(3.607\pm 0.017 \pm 0.056) \ \mathrm{nb}$and$\sigma(e^+e^-\to D^+D^-)=(2.882\pm 0.018 \pm 0.042) \ \mathrm{nb}$at a center of mass energy,$E_\mathrm{cm} = 3774 \pm 1$ MeV.Comment: 12 pages, 2 figures, and 6 tables. The Fig. 2 in this version corrects errors in plotting the fits in the original Fig. 2. Correcting these errors does not affect any result or text. We thank Dr. Maurice Garcia-Sciveres for pointing out this mistak

Inclusive Hadron Yields from Ds+ Decays

We study the inclusive decays of Ds+ mesons, using data collected near the Ds*+ Ds- peak production energy E_cm=4170 MeV by the CLEO-c detector. We report the inclusive yields of Ds+ decays to K^+ X, K^- X, KS0 X, pi^+ X, pi^- X, pi^0 X, eta X, eta' X, phi X, omega X and f0(980) X, and also decays into pairs of kaons, Ds+ -> KK-bar X. Using these measurements, we obtain an overview of Ds+ decays.Comment: 13 pages, available through http://www.lns.cornell.edu/public/CLNS/, submitted to PR

New Measurement of Exclusive Decays of the chi_c0 and chi_c2 to Two-Meson Final States

Using a sample of 2.59 times 10^7 psi(2S) decays collected by the CLEO--c detector, we present results of a study of chi_{c0} and chi_{c2} decays into two-meson final states. We present the world's most precise measurements of the chi_{cJ,(J=0,2)} -> pi^+pi^-, pi^0 pi^0, K^+K^-, K^0_S K^0_S, eta eta and eta^{prime} eta^{prime} branching fractions, and a search for chi_c decays into eta eta^{prime}. These results shed light on the mechanism of charmonium decays into pseudoscalar mesons.Comment: 7 pages, available through http://www.lns.cornell.edu/public/CLNS/, submitted to Phys. Rev.