7,272 research outputs found
Radiative vector meson decay
We study the radiative , and decay into and taking into account mechanisms in which there
are two sequential vector-vector-pseudoscalar or
axial-vector--vector--pseudoscalar steps followed by the coupling of a vector
meson to the photon, considering the final state interaction of the two mesons.
Other mechanisms in which two kaons are produced through the same sequential
mechanisms or from vector meson decay into two kaons which undergo final state
interaction leading to the final pair of pions or , are also
considered. The results of the parameter free theory, together with the
theoretical uncertainties, are compared with the latest experimental results at
Frascati and Novosibirsk.Comment: Prepared for the 10th International Symposium on Meson-Nucleon
Physics and the Structure of the Nucleo
Chiral Dynamics of scalar mesons: radiative decay and in the medium through nuclear photoproduction
In order to assess the relevance of chiral dynamics in the scalar sector we
address two recent problems: radiative decay of the , for which there are
quite recent data from Frascati, and the modification of the
properties in the nuclear medium seen through the photoproduction
in nuclei.Comment: Talk given at the High Energy Physics Workshop "Scalar Mesons: an
Interesting Puzzle for QCD", Utica, New York, May 200
Watson's theorem and the axial transition
We present a new determination of the axial form factors from
neutrino induced pion production data. For this purpose, the model of Hernandez
{\it et al.} [Phys. Rev. D76, 033005 (2007)] is improved by partially restoring
unitarity. This is accomplished by imposing Watson's theorem on the dominant
vector and axial multipoles. As a consequence, a larger , in good
agreement with the prediction from the off-diagonal Goldberger-Treiman
relation, is now obtained.Comment: 17 latex pages, 7 figures, 2 tables. Some typos correcte
Years of sunlight exposure and cataract: a case-control study in a Mediterranean population.
BACKGROUND: We aimed to investigate the relation between sunlight exposure and risk of cataract. METHODS: We carried out a frequency-matched case-control study of 343 cases and 334 controls attending an ophthalmology outpatient clinic at a primary health-care center in a small town near Valencia, Spain. All cases were diagnosed as having a cataract in at least one eye based on the Lens Opacification Classification system (LOCS II). Controls had no opacities in either eye. All cases and controls were interviewed for information on outdoor exposure, "usual" diet, history of severe episodes of diarrhea illness, life-style factors and medical and socio-demographic variables. Blood antioxidant vitamin levels were also analyzed. We used logistic regression models to estimate sex and age-adjusted odds ratios (ORs) by quintiles of years of occupational outdoor exposure, adjusting for potential confounders such as smoking, alcohol consumption, serum antioxidants and education. RESULTS: No association was found between years of outdoor exposure and risk of cataract. However, exploratory analyses suggested a positive association between years of outdoor exposure at younger ages and risk of nuclear cataract later in life. CONCLUSION: Our study does not support an association with cataract and sunlight exposure over adult life
Nuclear effects in neutrino induced reactions
We discuss the relevance of nuclear medium effects in the analysis of some
low and medium energy neutrino reactions of current interest. In particular, we
study the Quasi-Elastic (QE) process, where RPA correlations and Final State
Interactions (FSI) are shown to play a crucial role. We have also investigated
the neutrino induced coherent pion production. We find a strong reduction of
the cross section due to the distortion of the pion wave function and the
modification of the production mechanisms in the nucleus. The sensitivity of
the results to the axial coupling has been also
investigated.Comment: To appear in the proceedings of Chiral Symmetry in Hadron and Nuclear
Physics (Chiral07), Osaka, Japan, November 13-16, 200
Coleta de dados em campo com auxílio de dispositivos móveis Android.
Este Comunicado Técnico visa apresentar os passos necessários para a utilização do programa GeoPaparazzi no campo, incluindo a instalação e o funcionamento do programa, a geração de mapas base personalizados, a configuração de formulários de coleta de dados e a exportação dos dados coletados. Pressupõe-se que o leitor tenha domínio de algumas operações, como procedimentos para copiar dados do computador pessoal para o dispositivo móvel e vice-versa, gerar mapas base ou mosaicos georreferenciados e utilizar programas via linha de comando no computador pessoal.bitstream/item/99818/1/CT-34.pd
DYNAMIC RELATIONSHIPS: E-COMMERCE SALES AND KEY EXOGENOUS VARIABLES IN THE PHILIPPINES
This study delves into the complex and evolving landscape of e-commerce in the Philippines, focusing on the relationship between E-Commerce Sales as the endogenous variable and a set of influential exogenous variables, including Digital Marketing Spending, GDP Growth, Internet Penetration, and Mobile Phone Ownership. This research employs a flexible spline modeling approach, uncovers non-linear associations, and offers significant implications for academic understanding and practical applications. The findings underscore the growing impact of Digital Marketing Spending on E-Commerce Sales, revealing the paramount role of online advertising and promotional strategies in the digital marketplace. Moreover, the study explains the intricate interplay between GDP Growth, Internet Penetration, Mobile Phone Ownership, and E-Commerce Sales, highlighting the non-linear nature of these relationships. As the Philippines continues its economic expansion and technological integration, these associations exhibit insightful implications for policymakers, businesses, and e-commerce stakeholders. Article visualizations
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