3,012 research outputs found

    Heavy-Flavor Measurements by the PHENIX Experiment at RHIC

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    In recent years, PHENIX has studied many important observables related to heavy-flavor physics through their leptonic decay measurements including the invariant yield of electrons from nonphotonic sources, and prompt single muons, both of which are dominated by D and B mesons. Charm and beauty cross-sections were measured and compared through single lepton, and lepton-hadron correlations in p+p collisions at s\sqrt{s} = 200 GeV. Observables for quarkonia production such as invariant yield and polarization were also measured in p+p collisions. In Au+Au collisions, preliminary results for the RAAR_{AA} for single electrons and a 90% CL upper limit for the suppression of Υ\Upsilons were produced. And in dd+Au collisions, a preliminary RCPR_{CP} study for J/ψJ/\psi production in different centrality ranges was extracted.Comment: 8 pages, 9 figures, International Conference on Strangeness in Quark Matter Conference 2009 Proceeding

    On the Impact of COVID-19-Related Uncertainty

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    3noCOVID-19 has generated a substantial increase in the level of economic policy uncertainty (EPU) around the World. Recent empirical investigations suggest that the COVID-19 has played a key role in amplifying the overall level of political uncertainty. In Italy, where anti-COVID-19 measures were implemented with some delay and were badly communicated, EPU rose dramatically. We examine the implications of rising COVID-19-related uncertainty for company revenues, gross operating margin and employment in 16 different Italian sectors. Our findings indicate construction, education, manufacturing activities and hospitality as the most hit sectors, with an average short-term drop in company revenues of around 4% in annual terms and a recovery time of almost two years. Thus, COVID-19-related uncertainty is found to be a significant business cycle driver.openopenGufler, Ivan; Donadelli, Michael; Castellini, MartaGufler, Ivan; Donadelli, Michael; Castellini, Mart

    The macro and asset pricing implications of rising Italian uncertainty: Evidence from a novel news-based macroeconomic policy uncertainty index

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    We develop a new monthly and daily index of economic policy uncertainty for Italy based on articles from the Sole 24 Ore (a popular Italian business daily newspaper). VAR investigations document that an unexpected rise in the Sole 24 Ore news-based EPU index (EPU24) has mild effects on the real economic activity. Cross-sectional asset pricing tests then show that both monthly and daily EPU24 shocks command a positive risk premium. A standard event study finally indicates the presence of statistically significant positive cumulative abnormal returns (CARs) in the energy sector following different categories of policy-related events. Negative and significant CARs in the financial sector are instead found to be generated by international-related events and political elections

    Computing Macro-Effects and Welfare Costs of Temperature Volatility: A Structural Approach

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    We produce novel empirical evidence on the relevance of temperature volatility shocks for the dynamics of productivity, macroeconomic aggregates and asset prices. Using two centuries of UK temperature data, we document that the relationship between temperature volatility and the macroeconomy varies over time. First, the sign of the causality from temperature volatility to TFP growth is negative in the post-war period (i.e., 1950–2015) and positive before (i.e., 1800–1950). Second, over the pre-1950 (post-1950) period temperature volatility shocks positively (negatively) affect TFP growth. In the post-1950 period, temperature volatility shocks are also found to undermine equity valuations and other main macroeconomic aggregates. More importantly, temperature volatility shocks are priced in the cross section of returns and command a positive premium. We rationalize these findings within a production economy featuring long-run productivity and temperature volatility risk. In the model temperature volatility shocks generate non-negligible welfare costs. Such costs decrease (increase) when coupled with immediate technology adaptation (capital depreciation)

    The impact of knowledge loss on software projects: turnover, customer found defects, and dormant files

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    The success of a software project is dependent on the expertise and knowledge of its developers. In this dissertation, we use empirical studies to develop an understanding of the impact of knowledge loss on software projects. First, we studied the damage done to projects from turnover, the susceptibility of the project to future turnover, and the suggestion of potential successors to assume abandoned files. Based on the project vulnerability to turnover, project leaders can induce key developers to stay with the project and to mitigate files abandonment. Second, we did an empirical research on the impact of turnover on the quality of a software project. Third, we performed an examination of the impact of inactive files (dormant files). Our findings on the first research topic showed that the greater the spread of knowledge the less likely a project is to be affected by turnover. Moreover, we found that knowledgeable developers, rather than newcomers, take over abandoned code. In our second study, we observed an unexpected result that in the Chrome web-browser project, the number of developers who leave and join both decreased the number of post-release defects. We discuss this unexpected result. The third study on dormant files, i.e. inactive files, contrasted a legacy system with a popular system. We found that for a legacy system, the developers that take on dormant files were experienced developers

    European green policy announcements and sectoral stock returns

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    To fulfill the Paris Agreement commitments and stimulated by an unprecedented amount of public resources put in place to recover from the COVID-induced recession, European governments have recently announced sizable green policy plans. In this paper, we examine the behavior of green and brown portfolios around green policy-related announcements (GPAs) made by major European governments in 2020 via a standard event study analysis and the use of returns of stocks listed in the “STOXX 100 All Europe”. Our main empirical findings indicate the presence of positive cumulative abnormal returns (CARs) both in the green and brown sectors following GPAs. However, the estimated positive sentiment effect is stronger in the former sector. A size effect in terms of the amount of resources announced to be allocated for a specific category of policy is also observed. We find that the observed positive sentiment is mainly driven by announcements on climate change mitigation-related policies, which account for 70% of the total allocated funds. At the sector level, positive and significant CARs due to GPAs are found in the (i) energy, (ii) financial and (iii) industrial sectors. At the country level, GPAs are found to drive a significant positive sentiment effect in the following European countries: Switzerland, Spain, UK, Ireland and Italy. Sector- and country-level analyses confirm the presence of larger benefits from GPAs among more sustainable portfolios
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