ALICE potential for direct photon measurements in p-p and Pb-Pb collisions

The production of direct photons, not coming from hadron decays, at large transverse momentum pT > 2 GeV/c in proton-proton collisions at the LHC, is an interesting process to test the predictions of perturbative Quantum Chromodynamics at the highest energies ever and to put constraints on the gluon density in the proton. Furthermore, they provide a baseline reference for quark-gluon-plasma studies in Pb-Pb collisions. We will present the experimental capabilities of the ALICE electromagnetic calorimeter EMCal to reconstruct the direct and isolated photon spectra in p-p and Pb-Pb collisions

Modelling the Determinants of Job Creation: Microeconometric Models Accounting for Latent Entrepreneurial Ability

During the last decades, most developed countries have shown a remarcable increase in entrepreneurship rates. Recent research suggests that this increase is, for a considerable part, caused by an increase in the share of solo self-employed. Nowadays, for example, more than half of all Dutch business owners are solo self-employed. This raises the question which factors determine whether an entrepreneur becomes an employer or remains solo self-employed. A recent study by EIM investigates the decision of entrepreneurs whether or not to become an employer and the decision of employers to hire a certain number of employees. The first decision is examined by estimating duration models that model the duration of the time spent as solo entrepreneur before the transition to employer is made. The estimations are performed on a panel of Dutch start-ups in 1998, 1999 and 2000. We find that entrepreneurs who founded a firm to improve their work-life balance are less likely to make the transition to employership. The remaining factors that we found to influence the employer decision do this all in a positive way. These factors include whether or not the entrepreneur has the objective to maximize revenue, experience within the industry in which he operates, his entrepreneurial experience, selfefficacy, risk attitude and the time that is spent in the company. We also find that the likelihood of becoming a job creator is positively related to the business cycle. The second decision is examined by estimating count models that model the number of employees that are hired in the first year of employership. We find that higher levels of educational, entrepreneurial experience and self-efficacy of the entrepreneur lead to a greater firm size. Another factor that increases firm size is innovativeness. The moment in time at which the transition from soloentrepreneur to employer is made, also plays are role. For the first few years we find a negative relationship with firm age, indicating that the faster the switch is made, the more personnel will be employed. Also, for the employee decision we find a positive relation with the business cycle. �

Sensitivity of isolated photon production at TeV hadron colliders to the gluon distribution in the proton

We compare the single inclusive spectra of isolated photons measured at high transverse energy in proton-antiproton collisions at sqrt(s)=1.96 TeV with next-to-leading order perturbative QCD predictions with various parametrizations of the parton distribution functions (PDFs). Within the experimental and theoretical uncertainties, the Tevatron data can be reproduced equally well by the recent CTEQ6.6, MSTW08 and NNPDF1.2 PDF sets. We present also the predictions for isolated gamma spectra in proton-proton collisions at sqrt(s)=14TeV for central (y=0) and forward (y=4) rapidities relevant for LHC experiments. Different proton PDFs result in maximum variations of order 30% in the expected E_T-differential isolated gamma cross sections. The inclusion of the isolated photon data in global PDF fits will place extra independent constraints on the gluon density.Comment: Minor modifications. Matches published version. 13 pages, 10 figure

New Firm Performance: Does the Age of Founders Affect Employment Creation?

The ageing population increasingly becomes a challenge for policy makers. Given the expected changes in the age decomposition of the workforce, it becomes more pressing to understand the nature of the relationship between age and entrepreneurship. More specifically: what are the consequences of an ageing (entrepreneurial) population on entrepreneurial performance?� A recent study by EIM investigates the effect of the age of the entrepreneur at start-up on the size of newly started firms. A distinction is made between the decision of entrepreneurs whether or not to become an employer, and the decision of employers to hire a certain number of employees. To examine to which extent age has a direct and/or indirect effect on these two decision, a sample of 849 new firms has been used that survived the first three years after start-up.� A first conclusion of the empirical analysis is that it is important to make the distinction between the two decisions: the decision of entrepreneurs whether or not to become an employer depends on other factors than the decision of employers regarding the number of employees. A second conclusion is that age has a negative relationship with the outcome of both decisions, but that these relationships are completely mediated by the mediating variables included in the study. Entrepreneurs who start at older age are less likely to work fulltime in their new venture, are less willing to take risks and have a lower perception of their entrepreneurial skills. Each of these factors has, in turn, a positive impact on the probability of employing personnel. For the number of employees a negative indirect effect of age exists, through the effect of age on the perception of entrepreneurial skills. �

What determines the volume of informal venture finance investment and does it vary by gender?

We estimate a two-equation model to jointly determine the number of informal investors and the amount of money that they invest over the last 3 years. Our model uses data on 126,189 individuals in 21 highly developed countries in the period 2002-2006. We delve deeper into the hypothesis of Burke et al (2010) that ‘the demand for informal venture finance tends to generate its own supply’. To our knowledge, we undertake the first research to move analysis of the supply of informal venture finance investment beyond estimating the propensity for a person to become an informal investor and onto the core concern which is the total volume of venture finance. We find that a one per cent increase in entrepreneurial activity increases the number of informal investors by 1.702 per cent. However, the average invested amount declines by 0.827 per cent leading to a net positive total increase by 0.861 per cent. This result indicates that, to a considerable extent, demand for informal investment creates its own supply. This effect is stronger for males than females. We also find that the level of venture capital investment has a net positive effect on the level of informal investment and that this effect is stronger for females than males.

X-ray diffraction study of cadmium hydroxyapatite

Solid solutions of cadmium and calcium hydroxyapatite [Ca10−x Cdx (PO4)6 (OH)2 (0 ≤ x ≤ 10)] were synthesized by a wet process in a basic medium. The lattice dimensions of these compounds vary linearly with the atom percent cadmium. The distribution of the calcium and cadmium ions between two non- equivalent crystallographic sites, (1) and (2), were determined by the Rietveld method. The site-occupancy factors of atoms indicate a slight preference of cadmium for site (2) in the apatite structure

Studies of isolated photon production in simulated proton-proton collisions with ALICE-EMCal

The production of prompt photons at high transverse momentum in proton-proton collisions (p-p) is a useful tool to study perturbative Quantum-Chromo-Dynamics (pQCD). In particular, they yield valuable information about parton distribution functions in the proton. The experimental measurement of prompt photons is a difficult task due to the large background of decay photons from neutral mesons, mainly pi0. We present a full simulation and reconstruction study of prompt photons identification in p-p at sqrt(s) = 14 TeV in the ALICE electromagnetic calorimeter EMCal, giving details on the methods developed to separate them from decay photons with the help of shower-shape and isolation cuts. We present Monte Carlo predictions for signal and background. The method used to extract the final isolated corrected cross-section is presented and the calculation of various experimental corrections is outlined.Comment: 4 pages, 6 figures. Proceedings Hot Quarks 2010 La-Londe-les-Maures (France), JPG submitte

France

Racial and ethnic inequalities remain an underdeveloped area of research in France. This situation can mainly be attributed to the fact that researchers have been strongly influenced, on the one hand, by a political model of integration (presented in more detail in Section 12.3.3) that has led France ‘to ignore itself as a country of immigration’ (Noiriel, 1988) and encouraged a colorblind approach to social reality (Lorcerie, 1994a) and, on the other hand, by Marxist political and scientific perspectives giving central importance to class in the study of society. However, since the 1980s, due to important changes in the immigrant population and in policy towards immigrants, as well as to the arrival of a new generation of researchers and the growing internationalization of French research, the number of studies in this domain has increased and diversified. There are however very few reviews of the existing scientific literature (Lorcerie, 1995, 2003; Payet, 2003; Payet and van Zanten, 1996; van Zanten, 1997b) and only one in English (van Zanten, 1997a). Therefore, the following critical survey, based on a systematic sampling of the literature and covering 30 years of research, including very recent studies, should prove useful to various, and especially anglophone, audiences. [Chapter's first paragraph

Immigrants' educational attainment: A mixed picture, but often higher than the average in their country of origin

The immigrants living in France and the refugees who arrived in Austria are more educated than most of the population in their country of origin. By comparison with the population in the host country, the picture is more mixed: some groups, such as immigrants from Portugal living in France, are relatively low educated, while others, such as Romanians, have more frequently completed higher education than people born in France