Virtual contributions from D∗(2007)0D^{\ast}(2007)^0 and D∗(2010)±D^{\ast}(2010)^{\pm} in the B→DπhB\to D\pi h decays

We study the quasi-two-body decays $B\to D^*h \to D\pi h$ with $h=(\pi, K)$ in the perturbative QCD approach and focus on the virtual contributions from the off-shell $D^{\ast}(2007)^0$ and $D^{\ast}(2010)^{\pm}$ in the four measured decays $\bar B^0 \to D^0\pi^+\pi^-$, $\bar B^0\to D^0\pi^+K^-$, $B^- \to D^+\pi^-\pi^-$ and $B^- \to D^+\pi^-K^-$. For the $\bar B^0 \to D^{*+}\pi^-\to D^0\pi^+\pi^-$ and $\bar B^0\to D^{*+}K^-\to D^0\pi^+K^-$ decays, their branching fractions concentrate in a very small region of $m_{D^0\pi^+}$ near $D^{*+}$ pole mass, and the virtual contributions from $D^{*+}$, in the region $m_{D^0\pi^+}>2.1$ GeV, are about $5\%$ of the corresponding quasi-two-body results. We define two ratios $R_{D^{*+}}$ and $R_{D^{*0}}$, from which we conclude that the flavor-$SU(3)$ symmetry will be maintained for the $B\to D^* h\to D\pi h$ decays with very small breaking at any physical value of the $m_{D\pi}$. The $B^-\to D^{*0}\pi^-\to D^0\pi^0\pi^-$ and $B^-\to D^{*0}K^-\to D^0\pi^0K^-$ decays can be employed as a constraint for the $D^{*0}$ decay width, with preferred values consistent with previous theoretical predictions for this quantity.Comment: 12 pages, 5 figures. Published versio

Dynamical Behavior of Secondary Dengue Infection Model

With the increase of dengue cases in the last decades, efforts on controlling the dengue disease have been carried out. Dengvaxia, the first dengue vaccine developed by Sanofi Pasteur, was recommended by WHO for trial. The long-term safety follow-up indicates that the vaccine efficacy is higher in seropositive human population and there is an increase risk of severe dengue in vaccinated seronegative human. It is important to understand the dynamical behavior of dengue that includes both the seronegative and seropositive human population before performing vaccination. For such purpose, a secondary dengue infection model is developed and investigated in this paper. The basic reproduction number, Ro is derived and sensitivity analysis is performed to determine the most sensitive parameter in the model. The results indicate that Ro is the most sensitive to the ratio of mosquito to human, dengue transmission from human to mosquito, dengue transmission from mosquito to human and natural mortality of mosquito. It is also found that the ratio of seropositive to seronegative human population is 1.52 for a given set of parameter values at dengue endemic state. This would assist the authorities in deciding the proportion of seropositive and seronegative human population to be vaccinated. Numerical simulation results show that a decline in primary dengue infection is not associated with a decrease in secondary dengue infection. Therefore, the dengue control strategies should produce high efficacy in transmissibility reduction and ultimately reduce the DHF

Determination of pion distribution amplitudes from the electromagnetic form factor with the data-driven dispersion relation

We study the pion electromagnetic form factor in the modulus squared dispersion relation, and do the model independent extraction of the most important nonperturbative parameters in pion light-cone distribution amplitude. The motivation of this work is the recent measurement of timelike form factor in the resonant regions, which makes up the piece lacking solid QCD-based calculation. With the perturbative QCD calculation up to next-to-leading-order QCD corrections and twist four level of meson distribution amplitudes, we obtain the chiral mass of pion meson as $m_0^\pi(1 \, {\rm GeV}) = 1.31^{+0.27}_{-0.30} \, {\rm GeV}$. More accuracy measurement of the timelike form factor are desirable to help us to determine the lowest gegenbauer moments in pion distribution amplitudes with the data-driven dispersion relation method developed in this work.Comment: 9pages, 6 figures, 1 tabl

Changes of Carbon Emission in Chinese Regional Economy: A Decomposition Analysis Using Nested Logarithmic Mean Divisia Approach

This paper describes a nested logarithmic mean Divisia approach and analyzes the potential factors influencing the changes in carbon emission in Chinese northwest region for the period 1995-2010. The analysis is performed by decomposing annual carbon emission into components representing changes in economic activity, economic structure, energy mix, and energy intensity, population growth, population structure, as well as changes in per capita energy consumption and emission factor. This paper argues that the vast majority of changes in carbon emissions since 1995 are due to economic activity and energy intensity, where the former is found to be a predominant role in rising carbon emission and the later contributing dominantly to decreasing carbon emission. Moreover, the economic structure, population growth, and population structure effects are all found responsible for carbon emissions in the region, although their effects reverse in different time period. Besides, the decreases in carbon emission, however, are attributable mainly to per capita energy consumption and energy mix. There is no doubt that the current emission profile poses significant challenges to the local government’s policies for emission reduction. It is of vital importance to take into account the regional and stage characteristics of influences on carbon emission for policy making

New Weather Indices for China: Tool of Risk Control of International Supply Chain

China is at the core of the world’s supply chain because of its focus on production and consumption. However, as weather can significantly affect supply chain operations, China plans to introduce weather derivatives to secure the multinational supply chain. Using historical records over the decade, weather derivatives could be an important tool for hedging risk and meeting the needs of Chinese market. In this paper, new weather indices for China financial markets are experimentally created through simulated machine learning to assess the ability of the weather indices to reduce risk. Through a simulation test from 2008 to 2017, the indices were found to successfully match 98% of the risk with the situation across two dimensions: i). changing Chinese weather data; and ii). a connection with US weather indices

The Quantified NTO Analysis for the Electronic Excitations of Molecular Many-Body Systems

We show that the origin of electronic transitions of molecular many-body systems can be revealed by a quantified natural transition orbitals (QNTO) analysis and the electronic excitations of the total system can be mapped onto a standard orbitals set of a reference system. We further illustrate QNTO on molecular systems by studying the origin of electronic transitions of DNA moiety, thymine and thymidine. This QNTO analysis also allows us to assess the performance of various functionals used in time-dependent density functional response theory.Comment: Main Text+Supplemental Material; G09 reference correcte

A Hybrid Model to Analyze Air Pollution Spread Scales in Xi\u27 an and Surrounding Cities

Air quality analysis and prediction are very important in environmental research as airborne pollution has become a significant health threat, especially in Chinese urban agglomerations. Most previous analysis systems have been based on direct factors, such as pollutant concentrations, wind speeds and direction, relative humidity, and temperature; however, the air quality in a city is also affected by the air quality conditions in surrounding areas. This paper proposes a novel strategy for the analysis and forecast of air quality levels, for which Artificial Neural Networks (ANNs) are employed to elucidate the complex relationships between air quality and meteorological predictor variables. The experimental results in the study demonstrated that the normalized EEMD-ANN model outperformed other models in terms of the Precise, MAE and MAPE. The proposed model, therefore, demonstrated its potential as an administrative tool for issuing air pollution forecasts and for designing suitable abatement strategies