Higher meson resonances in ρ→π0π0γ\rho \to \pi^0 \pi^0 \gamma and ω→π0π0γ\omega \to \pi^0 \pi^0 \gamma

The role of higher meson resonances with spin 1 and 2 is investigated quantitatively in the decay processes of $\rho \to \pi^0\pi^0 \gamma$ and $\omega \to \pi^0 \pi^0 \gamma$. Among the higher resonances, we find that the $f_2(1270)$ tensor meson can give a nontrivial contribution especially to the $\omega \to \pi^0 \pi^0 \gamma$ decay process. When the $f_2$ contribution is combined with the processes involving the vector and scalar meson intermediate states, a good agreement with the recent measurements is achieved for both decays. The effect of the $f_2(1270)$ is found to be sizable at the intermediate photon energies and may be verified by precise measurements of the recoil photon spectrum of the $\omega \to \pi^0 \pi^0 \gamma$ decay. The dependence of the decay widths on various models for the $\rho$-$\omega$ mixing in the literature is also investigated.Comment: 16 pages, REVTeX, 6 figures, revised version, to appear in Phys. Rev.

Quantal description of nucleon exchange in stochastic mean-field approach

Nucleon exchange mechanism is investigated in central collisions of symmetric heavy-ions in the basis of the stochastic mean-field approach. Quantal diffusion coefficients for nucleon exchange are calculated by including non-Markovian effects and shell structure. Variances of fragment mass distributions are calculated in central collisions of ${}^{40}$Ca + ${}^{40}$Ca, ${}^{48}$Ca + ${}^{48}$Ca and ${}^{56}$Ni + ${}^{56}$Ni systems

rho(omega)-> pi^0 pi^0 gamma, rho(omega) -> eta pi^0 gamma decays in the local quark Nambu--Jona-Lasinio model

The branching ratios and photon spectra of the rare processes rho(omega)-> pi^0 pi^0 gamma, rho(omega) -> eta pi^0 gamma are calculated in the framework of the standard local quark Nambu--Jona-Lasinio (NJL) model. Three types of diagrams are considered: the quark box and the pole diagrams with scalar (sigma,a_0(980)) and vector (rho,omega) mesons. The obtained estimations for the widths of the processes rho(omega)-> pi^0 pi^0 gamma are in satisfactory agreement with existing experimental data. Predictions are made for the widths of the processes rho(omega) -> eta pi^0 gamma.Comment: 6 pages, 5 figure

Collisional Damping of Nuclear Collective Vibrations in a Non-Markovian Transport Approach

A detailed derivation of the collisional widths of collective vibrations is presented in both quantal and semi-classical frameworks by considering the linearized limits of the extended TDHF and the BUU model with a non-Markovian binary collision term. Damping widths of giant dipole and giant quadrupole excitations are calculated by employing an effective Skyrme force, and the results are compared with GDR measurements in Lead and Tin nuclei at finite temperature.Comment: 23 pages, 6 Figure

Radiative Scalar Meson Decays in the Light-Front Quark Model

We construct a relativistic $^3P_0$ wavefunction for scalar mesons within the framework of light-front quark model(LFQM). This scalar wavefunction is used to perform relativistic calculations of absolute widths for the radiative decay processes$(0^{++})\to\gamma\gamma,(0^{++})\to\phi\gamma$, and $(0^{++})\to\rho\gamma$ which incorporate the effects of glueball-$q\bar{q}$ mixing. The mixed physical states are assumed to be $f_0(1370),f_0(1500)$,and $f_0(1710)$ for which the flavor-glue content is taken from the mixing calculations of other works. Since experimental data for these processes are poor, our results are compared with those of a recent non-relativistic model calculation. We find that while the relativistic corrections introduced by the LFQM reduce the magnitudes of the decay widths by 50-70%, the relative strengths between different decay processes are fairly well preserved. We also calculate decay widths for the processes $\phi\to(0^{++})\gamma$ and (0^{++})\to\gamma\gamm involving the light scalars $f_0(980)$ and $a_0(980)$ to test the simple $q\bar{q}$ model of these mesons. Our results of $q\bar{q}$ model for these processes are not quite consistent with well-established data, further supporting the idea that $f_0(980)$ and $a_0(980)$ are not conventional $q\bar{q}$ states.Comment: 10 pages, 4 figure

The deuteron: structure and form factors

A brief review of the history of the discovery of the deuteron in provided. The current status of both experiment and theory for the elastic electron scattering is then presented.Comment: 80 pages, 33 figures, submited to Advances in Nuclear Physic

Scalar sigma meson effects in radiative rho^0-meson decays

We study the radiative $\rho^0\to \pi^+\pi^-\gamma$ and $\rho^0\to \pi^0\pi^0\gamma$ decays and we calculate their branching ratios using a phenomenological approach by adding to the amplitude calculated within the framework of chiral perturbation theory and vector meson dominance the amplitude of $\sigma$-meson intermediate state. Our results for the branching ratios are in good agreement with the experimental values.Comment: to be published in Phys. Rev.

Global, regional, and national incidence and mortality for HIV, tuberculosis, and malaria during 1990–2013: a systematic analysis for the Global Burden of Disease Study 2013

BACKGROUND: The Millennium Declaration in 2000 brought special global attention to HIV, tuberculosis, and malaria through the formulation of Millennium Development Goal (MDG) 6. The Global Burden of Disease 2013 study provides a consistent and comprehensive approach to disease estimation for between 1990 and 2013, and an opportunity to assess whether accelerated progress has occured since the Millennium Declaration. METHODS: To estimate incidence and mortality for HIV, we used the UNAIDS Spectrum model appropriately modified based on a systematic review of available studies of mortality with and without antiretroviral therapy (ART). For concentrated epidemics, we calibrated Spectrum models to fit vital registration data corrected for misclassification of HIV deaths. In generalised epidemics, we minimised a loss function to select epidemic curves most consistent with prevalence data and demographic data for all-cause mortality. We analysed counterfactual scenarios for HIV to assess years of life saved through prevention of mother-to-child transmission (PMTCT) and ART. For tuberculosis, we analysed vital registration and verbal autopsy data to estimate mortality using cause of death ensemble modelling. We analysed data for corrected case-notifications, expert opinions on the case-detection rate, prevalence surveys, and estimated cause-specific mortality using Bayesian meta-regression to generate consistent trends in all parameters. We analysed malaria mortality and incidence using an updated cause of death database, a systematic analysis of verbal autopsy validation studies for malaria, and recent studies (2010-13) of incidence, drug resistance, and coverage of insecticide-treated bednets. FINDINGS: Globally in 2013, there were 1·8 million new HIV infections (95% uncertainty interval 1·7 million to 2·1 million), 29·2 million prevalent HIV cases (28·1 to 31·7), and 1·3 million HIV deaths (1·3 to 1·5). At the peak of the epidemic in 2005, HIV caused 1·7 million deaths (1·6 million to 1·9 million). Concentrated epidemics in Latin America and eastern Europe are substantially smaller than previously estimated. Through interventions including PMTCT and ART, 19·1 million life-years (16·6 million to 21·5 million) have been saved, 70·3% (65·4 to 76·1) in developing countries. From 2000 to 2011, the ratio of development assistance for health for HIV to years of life saved through intervention was US$4498 in developing countries. Including in HIV-positive individuals, all-form tuberculosis incidence was 7·5 million (7·4 million to 7·7 million), prevalence was 11·9 million (11·6 million to 12·2 million), and number of deaths was 1·4 million (1·3 million to 1·5 million) in 2013. In the same year and in only individuals who were HIV-negative, all-form tuberculosis incidence was 7·1 million (6·9 million to 7·3 million), prevalence was 11·2 million (10·8 million to 11·6 million), and number of deaths was 1·3 million (1·2 million to 1·4 million). Annualised rates of change (ARC) for incidence, prevalence, and death became negative after 2000. Tuberculosis in HIV-negative individuals disproportionately occurs in men and boys (versus women and girls); 64·0% of cases (63·6 to 64·3) and 64·7% of deaths (60·8 to 70·3). Globally, malaria cases and deaths grew rapidly from 1990 reaching a peak of 232 million cases (143 million to 387 million) in 2003 and 1·2 million deaths (1·1 million to 1·4 million) in 2004. Since 2004, child deaths from malaria in sub-Saharan Africa have decreased by 31·5% (15·7 to 44·1). Outside of Africa, malaria mortality has been steadily decreasing since 1990. INTERPRETATION: Our estimates of the number of people living with HIV are 18·7% smaller than UNAIDS's estimates in 2012. The number of people living with malaria is larger than estimated by WHO. The number of people living with HIV, tuberculosis, or malaria have all decreased since 2000. At the global level, upward trends for malaria and HIV deaths have been reversed and declines in tuberculosis deaths have accelerated. 101 countries (74 of which are developing) still have increasing HIV incidence. Substantial progress since the Millennium Declaration is an encouraging sign of the effect of global action. FUNDING: Bill & Melinda Gates Foundation

Interference effects in the decay \phi\to \pi^{0}\pi^{0}\gamma and the coupling constant g_{\phi\sigma\gamma}

We study the radiative decay $\phi\to\pi^{0}\pi^{0}\gamma$ within the framework of a phenomenological approach in which the contributions of $\sigma$-meson, $\rho$-meson and $f_0$-meson are considered. We analyze the interference effects between different contributions and utilizing the experimental branching ratio for this decay we estimate the coupling constant $g_{\phi\sigma\gamma}$.Comment: 12 Pages in REVTEX, 5 Figures, to be published in Phys.Rev.