Road pricing as a citizen-candidate game

We construct a political economy model to analyze the political acceptability of road pricing policies. We use a citizen-candidate framework with a population composed by three groups differing for their income level. We show that road pricing policies are never applied when there is no redistribution of the resources in favour of other modes of transport or when the congestion of these types of transport is relatively high. The results suggest that the efficiency of the redistribution of resources from road to the alternative types of transport as well as the fraction of the population that uses the road transport are key factors in explaining the adoption of road pricing schemes

Comparative study of three-nucleon force models in A=3,4A=3,4 systems

Using modern nucleon-nucleon interactions in the description of the $A=3,4$ nuclei, it is not possible to reproduce both the three- and four-nucleon binding energies simultaneously. This is one manifestation of the necessity of including a three-nucleon force in the nuclear Hamiltonian. In this paper we will perform a comparative study of some, widely used, three-nucleon force models. We will analyze their capability to describe the aforementioned binding energies as well as the $n-d$ doublet scattering length. A correct description of these quantities can be considered a stringent requirement for a nuclear Hamiltonian containing two- and three-nucleon interaction terms. As we will show, this requirement is not fulfilled by several of the models available in the literature. To satisfy it, we propose modifications in the parametrization of the three-nucleon forces and we study their effects on few selected $N-d$ low energy scattering observables.Comment: 30 pages, 10 figure

The α+d→ 6Li+γ\alpha + d \rightarrow ~ ^6\mathrm{Li} + \gamma astrophysical SS-factor and its implications for Big Bang Nucleosynthesis

The \alpha+d\rightarrow\, ^6{\rm Li}+\gamma radiative capture is studied in order to predict the $^6$Li primordial abundance. Within a two-body framework, the $\alpha$ particle and the deuteron are considered the structureless constituents of $^6$Li. Five $\alpha+d$ potentials are used to solve the two-body problem: four of them are taken from the literature, only one having also a tensor component. A fifth model is here constructed in order to reproduce, besides the $^6$Li static properties as binding energy, magnetic dipole and electric quadrupole moments, also the $S$-state asymptotic normalization coefficient (ANC). The two-body bound and scattering problem is solved with different techniques, in order to minimize the numerical uncertainty of the present results. The long-wavelength approximation is used, and therefore only the electric dipole and quadrupole operators are retained. The astrophysical $S$-factor is found to be significantly sensitive to the ANC, but in all the cases in good agreement with the available experimental data. The theoretical uncertainty has been estimated of the order of few % when the potentials which reproduce the ANC are considered, but increases up to $\simeq 20$ % when all the five potential models are retained. The effect of this $S$-factor prediction on the $^6$Li primordial abundance is studied, using the public code PArthENoPE. For the five models considered here we find $^6{\rm Li}/$H$= (0.9 - 1.8) \times 10^{-14}$, with the baryon density parameter in the 3-$\sigma$ range of Planck 2015 analysis, $\Omega_b h^2= 0.02226 \pm 0.00023$.Comment: 26 pages, 9 figure

Effect of three nucleon forces in p-3He scattering

The effect of the inclusion of different models of three nucleon (3N) forces in p-3He elastic scattering at low energies is studied. Two models have been considered: one derived from effective field theory at next-to-next-to-leading order and one derived from a more phenomenological point of view -- the so-called Illinois model. The four nucleon scattering observables are calculated using the Kohn variational principle and the hyperspherical harmonic technique and the results are compared with available experimental data. We have found that with the inclusion of both 3N force models the agreement with the experimental data is improved, in particular for the proton vector analyzing power A_y.Comment: 8 pages, 4 figures, talk presented at the 20th International IUPAP Conference on Few-Body Problems in Physics, 20 - 25 August, 2012, Fukuoka, Japa

Effect of three-nucleon interaction in p-3He elastic scattering

We present a detailed study of the effect of different three-nucleon interaction models in p-3He elastic scattering at low energies. In particular, two models have been considered: one derived from effective field theory at next-to-next-to-leading order and one derived from a more phenomenological point of view -- the so-called Illinois model. The four-nucleon scattering observables are calculated using the Kohn variational principle and the hyperspherical harmonics technique and the results are compared with available experimental data. We have found that the inclusion of either one of the other force model improves the agreement with the experimental data, in particular for the proton vector analyzing power.Comment: 4 pages, 3 figure

Implication of the proton-deuteron radiative capture for Big Bang Nucleosynthesis

The astrophysical $S$-factor for the radiative capture $d(p,\gamma)^3$He in the energy-range of interest for Big Bang Nucleosynthesis (BBN) is calculated using an {\it ab-initio} approach. The nuclear Hamiltonian retains both two- and three-nucleon interactions - the Argonne $v_{18}$ and the Urbana IX, respectively. Both one- and many-body contributions to the nuclear current operator are included. The former retain for the first time, besides the $1/m$ leading order contribution ($m$ is the nucleon mass), also the next-to-leading order term, proportional to $1/m^3$. The many-body currents are constructed in order to satisfy the current conservation relation with the adopted Hamiltonian model. The hyperspherical harmonics technique is applied to solve the $A=3$ bound and scattering states. A particular attention is used in this second case in order to obtain, in the energy range of BBN, an uncertainty on the astrophysical $S$-factor of the order or below $\sim$1 %. Then, in this energy range, the $S$-factor is found to be $\sim$10 % larger than the currently adopted values.Part of this increase (1-3 %) is due to the $1/m^3$ one-body operator, while the remaining is due to the new more accurate scattering wave functions. We have studied the implication of this new determination for the $d(p,\gamma)^3$He $S$-factor on deuterium primordial abundance. We find that the predicted theoretical value for $^2$H/H is in excellent agreement with its experimental determination, using the most recent determination of baryon density of Planck experiment, and with a standard number of relativistic degrees of freedom $N_{\rm eff}=3.046$ during primordial nucleosynthesis.Comment: 5 pages, 2 figures, submitted to Phys. Rev. Let

DESIGN OF A STATED RANKING EXPERIMENT TO STUDY INTERACTIVE FREIGHT BEHAVIOUR: AN APPLICATION TO ROME'S LTZ

City logistics policies require an understanding of several issues (e.g. freight distribution context, preferences and relationship among agents) seldom accounted for in current research. Policies run the risk of producing unsatisfactory results because behavioural and contextual aspects are not considered. The acquisition of relevant data is crucial to test hypothesis and forecast agents' reactions to policy changes. Despite recent methodological advances in modelling interactive behaviour the development of apt survey instruments is still lacking to test innovative policies acceptability. This paper expands and innovate the methodological literature by describing a stated ranking experiment to study freight agent interactive behaviour and discusses the experimental design implemented to incorporate agent-specific priors when efficient design techniques are employed.urban freight distribution, group decision making, agent-specific interaction, stated preference, stated ranking experiments

Navigating Unfamiliar Terrain: Reconciling Conflicting Impressions of China’s Intellectual Property Regime in an Effort to Aid Foreign Right Holders

While imperial China was a notably inventive place, formal intellectual property protections analogous to those in the West failed to emerge there of their own accord. The deep influence of Confucianism on imperial Chinese society brought about a culture that subordinated individual desires to group harmony and perceived original creations as products not of individual people but of the society to which they belonged. Moreover, Confucianism\u27s influence on education and literature rendered verbatim copying not merely an accepted practice but a fundamental aspect of scholarship. Buddhism\u27s close connection to the emergence of printing in China also served to delay by centuries the first claims by authors of ownership interests in their works. Accordingly, the impetus for China\u27s modern intellectual property regime came from abroad. After China\u27s defeat in the Opium War, foreign investment in China increased dramatically and Western commercial interests began to press China for the legal recognition of their intellectual property rights. An effective enforcement regime, however, eluded China until the birth of the PRC. Since the late 1970s, the PRC has taken efforts to integrate China\u27s intellectual property regime with international institutions. China acceded to TRIPS in 1999 and joined the WTO in 2001. In tandem with these legal developments, China\u27s economy has rapidly become the world\u27s second largest, a fact attributable largely to foreign direct investment. China\u27s economic rise especially affects foreign holders of intellectual property rights. Commentators, however, differ starkly in their assessments of the ability of China\u27s intellectual property institutions to combat infringement. On the one hand, China\u27s apologists claim that such institutions are -- or imminently will be -- sufficient to provide for the just and efficient resolution of disputes arising out of infringement. On the other hand, China\u27s critics, particularly those in the United States, contend that China\u27s intellectual property regime fails to deter and remedy infringement. Ultimately, the views of China\u27s apologists are misleading. China\u27s specialized intellectual property tribunals have proven to be relatively effective, but insufficient resources, judicial corruption, and the inability of judges to act independent of the Chinese Communist Party hinder the effectiveness of China\u27s judiciary. China\u27s fragmented administrative enforcement bureaucracy, which handles the overwhelming majority of disputes arising out of infringement, suffers from a host of problems that work to the detriment of right holders. Criminal enforcement almost always results in convictions, yet procedural inefficiencies render such convictions frustratingly difficult to achieve. These shortcomings may be attributed to certain historical phenomena. Specifically, the Chinese state, in administering China\u27s intellectual property regime, has adopted an approach that comports with Confucianism\u27s elevation of state prerogatives at the expense of individual interests. Trends in patent law reform, trade secret litigation, and trademark enforcement bolster this conception of the Chinese state\u27s motivations. Foreign right holders, therefore, cannot reasonably expect China\u27s intellectual property regime to serve their interest in combating infringement. Consequently, foreign victims of infringement should seek to reverse the trend of anemic foreign litigation in China and employ China\u27s courts, especially the intellectual property tribunals, to vindicate their rights. Indeed, the Chinese government appears disinclined to take foreign perspectives under consideration in drafting new intellectual property legislation, a trend that may render the courts the only venue where foreign right holders can air their grievances. Finally, foreign right holders might also attempt to initiate private criminal prosecutions against infringers, although this avenue of enforcement is less likely to deliver favorable results

Electrodisintegration of 3^3He below and above deuteron breakup threshold

Recent advances in the study of electrodisintegration of 3He are presented and discussed. The pair-correlated hyperspherical harmonics method is used to calculate the initial and final state wave functions, with a realistic Hamiltonian consisting of the Argonne v18 two-nucleon and Urbana IX three-nucleon interactions. The model for the nuclear current and charge operators retains one- and many-body contributions. Particular attention is made in the construction of the two-body current operators arising from the momentum-dependent part of the two-nucleon interaction. Three-body current operators are also included so that the full current operator is strictly conserved. The present model for the nuclear current operator is tested comparing theoretical predictions and experimental data of pd radiative capture cross section and spin observables.Comment: 5 pages, 5 figures, submitted to Eur. Phys. J.