Improving MadGraph5 importance sampling efficiency by using neural networks

In this work, we present a two-staged unweighting method for Monte Carlo event generation. This method is based on the use of an Artificial neural network surrogate, which is trained to predict the events weights. The surrogate is used in a first unweighting step in order to avoid the evaluation of the true weights for the rejected events. Then, a second unweighting accounts for the error committed by the surrogate. This algorithm can accelerate the unweighting thanks to the much faster evaluation of the surrogate in respect to the evaluation of true weight, and to a small allowed overweight in the final sample. We test this algorithm for two scattering processes at 13 TeV, which are: pp → t ̄t and pp → e−e+ggd ̄d

Methods to study event-by-event fluctuations in the NA61/SHINE experiment at the CERN SPS

Theoretical calculations locate the critical point of strongly interacting matter (CP) at energies accessible at the CERN SPS. Event-by-event transverse momentum and multiplicity fluctuations are considered as one of the most important tools to search for the CP. Pilot studies of the energy dependence and the system size dependence of both $p_T$ and multiplicity fluctuations were performed by the NA49 experiment. The NA61/SHINE ion program is a continuation of these efforts. After briefly recalling the essential NA49 results on fluctuations we will discuss the technical methods (removing Non-Target interactions) which we plan to apply for future transverse momentum and multiplicity fluctuation analyses.Comment: Proceedings of CPOD 2010, 23-29 August, JINR, Dubn

Status and plans of the ion program of NA61 at the CERN SPS

The NA61/SHINE at the CERN SPS is a new experiment to study hadron production in p+p p+A, h+A and A+A interactions. The main goal of the NA61 ion program is to explore the phase diagram (T - mu_B) of strongly interacting matter. In particular, we plan to study the properties of the onset of deconfinement and to search for the signatures of the critical point. A two-dimensional scan of the phase diagram will be performed by varying the energy (13A-158A GeV) and system size (p+p, Be+Be, Ar+Ca, Xe+La) of collisions. This paper summarizes the status and plans of the NA61/SHINE ion program. In particular the detector upgrades, data taking schedule and the first results on spectra and correlations are discussed.Comment: Proceedings of "Critical Point and Onset of Deconfinement - CPOD 2011", Wuhan, November 7-11, 2011, version accepted by Central European Journal of Physic

Event by Event Analysis and Entropy of Multiparticle Systems

The coincidence method of measuring the entropy of a system, proposed some time ago by Ma, is generalized to include systems out of equilibrium. It is suggested that the method can be adapted to analyze multiparticle states produced in high-energy collisions.Comment: 13 pages, 2 figure

The Local Emergence and Global Diffusion of Research Technologies: An Exploration of Patterns of Network Formation

Grasping the fruits of "emerging technologies" is an objective of many government priority programs in a knowledge-based and globalizing economy. We use the publication records (in the Science Citation Index) of two emerging technologies to study the mechanisms of diffusion in the case of two innovation trajectories: small interference RNA (siRNA) and nano-crystalline solar cells (NCSC). Methods for analyzing and visualizing geographical and cognitive diffusion are specified as indicators of different dynamics. Geographical diffusion is illustrated with overlays to Google Maps; cognitive diffusion is mapped using an overlay to a map based on the ISI Subject Categories. The evolving geographical networks show both preferential attachment and small-world characteristics. The strength of preferential attachment decreases over time, while the network evolves into an oligopolistic control structure with small-world characteristics. The transition from disciplinary-oriented ("mode-1") to transfer-oriented ("mode-2") research is suggested as the crucial difference in explaining the different rates of diffusion between siRNA and NCSC

Equation of State for Hot and Dense Matter: σ\sigma-ω\omega-ρ\rho Model with Scaled Hadron Masses and Couplings

The proposed earlier relativistic mean-field model with hadron masses and coupling constants depending on the $\sigma$-meson field is generalized to finite temperatures. Within this approach we simulate the in-medium behavior of the hadron masses motivated by the Brown-Rho scaling. The high-lying baryon resonances and boson excitations as well as excitations of the $\sigma$, $\omega$ and $\rho$ fields interacting via mean fields are incorporated into this scheme. Thermodynamic properties of hot and dense hadronic matter are elaborated with the constructed equation of state. Even at zero baryon density, effective masses of $\sigma$-$\omega$-$\rho$-$N$ excitations abruptly drop down for T\gsim 170 MeV and reach zero at a critical temperature $T=T_{c\sigma}\sim 210$ MeV. Below $T_{c\sigma}$ (at $T\sim 190$ MeV) the specific heat gets a peak like at crossover. We demonstrate that our EoS can be matched with that computed on the lattice for high temperatures provided the baryon resonance couplings with nucleon are partially suppressed. In this case the quark liquid would masquerade as the hadron one. The model is applied to description of heavy ion collisions in a broad collision energy range. It might be especially helpful for studying phase diagram in the region near possible phase transitions.Comment: 53 pages, 16 figures; minor changes made, references adde

The development and growth of the software industry in Ireland: an institutionalized relationship approach

peer-reviewedIreland's software industry emerged in the 1970s and 1980s due to significant international developments and, more importantly, the industrial policy approach adopted in Ireland. The attraction of software foreign direct investment during these decades was followed by the emergence of an internationally competitive Irish software sector. A multitude of factors combine to explain the trajectory of software in Ireland: from developments related to globalization and international trade, to policy makers' efforts to promote an industry where Ireland could forge a comparative advantage internationally. An analysis of industrial dynamics and institutionalized relationships (IRs) furthers our understanding of significant developments in the industry in terms of interactions between firms, government and other stakeholders. This paper makes a novel contribution by analysing Ireland's software industry within the IR framework. The IR approach we employ focuses on the finance IR, the purchase IR, the employment IR, and the commercial IR. The adoption of the IR framework approach is particularly insightful in the Irish case as it facilitates a multifaceted analysis of the complex relationships that have moulded the Irish software industry. Such an approach also facilitates a study of the policy implications and policy prescriptions that are pertinent to the software sector.ACCEPTEDpeer-reviewe

The Triple Helix in the context of global change: dynamics and challenges

Understanding how economies change through interactions with science and government as different spheres of activity requires both new conceptual tools and methodologies. In this paper, the evolution of the metaphor of a Triple Helix of university–industry–government relations is elaborated into an evolutionary model, and positioned within the context of global economic changes. We highlight how Triple Helix relations are both continuing and mutating, and the conditions under which a Triple Helix might be seen to be unraveling in the face of pressures on each of the three helices – university, industry, and government. The reciprocal dynamics of innovation both in the Triple Helix thesis and in the global economy are empirically explored: we find that footlooseness of high technology manufacturing and knowledge-intensive services counteract the embeddedness prevailing in medium technology manufacturing. The geographical level at which synergy in Triple Helix relations can be expected and sustained varies among nations and regions

Bringing 'place' back in: regional clusters, project governance, and new product outcomes

We examine new product outcomes in the context of regional clusters. Based on past research on marketing relationships, clusters, and social networks, we propose that the overall configuration of a cluster helps promote particular governance practices among its members. These practices have distinct value-creating properties, and when they are brought to bear on a specific new product development project within a cluster, they promote performance outcomes like product novelty and speed to market. Ultimately, these performance effects are reinforced by the configuration of the cluster itself. In general, we propose that new product outcomes follow from complex interactions between a cluster's macro-level configuration and its micro-level governance processes. More broadly, our framework points to the importance of geographical variables and to the role of “place” in marketing decision-making