Slow proton production in semi-inclusive DIS off nuclei: the role of final state interaction

The effects of the final state interaction on the production of slow protons in semi-inclusive deep-inelastic lepton scattering off nuclei is considered within the spectator mechanism and a realistic approach in which the rescattering in the medium of both the recoiling proton and the hadronizing nucleon debris are taken into account.Comment: 4 pages, 4 figures, to appear in the Proceedings of the "Fifth International Conference on Perspectives in Hadronic Physics" held at ICTP, Trieste, 22 - 26 May 200

Nucleon-Nucleon Correlations and Final State Interaction in Inclusive Quasi-Elastic Electron Scattering off Nuclei at x>1

Inclusive quasi-elastic electron scattering off nuclei is investigated at high momentum transfer (Q^2>1 (GeV/c)^2) and x>1 adopting a consistent treatment of nucleon-nucleon correlations in initial and final states. It is shown that in case of light as well as complex nuclei the inclusive cross section at 1.3<x<2 is dominated by the absorption of the virtual photon on a pair of correlated nucleons and by their elastic rescattering in the continuum, whereas at x>2 it is governed by the rescattering of the outgoing off-mass-shell nucleon in the complex optical potential generated by the ground state of the residual (A-1)-nucleon system.Comment: 06100 Perugia, Italy (b) Istituto Nazionale di Fisica Nucleare, Sezione Sanita', Viale Regina Elena 299, I-00161 Roma, Italy 8 pages, preprint INFN-ISS 94/1, January 1994 (to appear in Phys. Lett. B

Creative Destruction and Cultural Lag in the Digital Age

Recently, there has been renewed interest in the two ideas of \u201ccreative destruction\u201d and \u201ccultural lag\u201d both brought together in this article to analyze cutting-edge changes in the digital world, especially as they relate to consumption. Several studies have documented that we are increasingly living in a hybridized environment of swiftly evolving devices and technologies. Within this context, cultural lag refers both to the conflict between digital versus material consumerist developments, as well as to the subsequent delays in social understanding. Creative destruction describes the introduction of new forms of consumption that eliminate existing ones. However while all destruction tends to lead to cultural lag, this is especially true in the case of creative destruction. The article will also suggest at the end that not all destruction, especially, but not exclusively, as it relates to the environment, is necessarily creative. It can also be mainly, if not exclusively and totally, destructive

Motivations to volunteer and social capital: the role of intrinsic motivations in promoting networks of cooperative relations

Although intrinsic motivations receive increasing attention in explaining human actions, our knowledge on their causes and effects is incomplete. Quite surprisingly, the existing literature fails to consider the relationship between intrinsic motivations and social capital formation. The present paper increases understanding on the effect of intrinsic motivations by studying the role that different motivations to volunteer have on the creation of volunteers’ social capital which is intended as networks of cooperative relations. Our empirical analysis considers three indices of social capital, aimed at measuring both the quantitative (number) and the qualitative (degree of familiarity and cooperation) character of social relations, and intrinsic and extrinsic motivations to volunteer (ideal motivations, the desire to feel useful to others, the pursuit of social recognition and the desire to increase the number of acquaintances or friends). We find that the creation of social capital through participation in voluntary associations is not indifferent to the motivations which induced the volunteer to start his/her unpaid activity. In particular, we show that intrinsic motivations enable people to extend their social networks by creating relations characterized by a significant degree of familiarity. By contrast, extrinsic motivations, and in particular the decision to join an association in order to increase the number of acquaintances or friends, promote the creation of networks from a quantitative point of view, but they do not facilitate the creation of relations based on a particular degree of confidence.Intrinsic Motivations, Social Capital, Volunteer Work, Social Networks

Universality of many-body two-nucleon momentum distributions: the correlated nucleon spectral function of complex nuclei revisited

Realistic NN interactions and many-body approaches have been used to calculate ground-state properties of nuclei with A=3, 4, 12, 16, 40, with particular emphasis on various kinds of momentum distributions. It is shown that at proper values of the relative (rel) and center-of-mass (c.m.) momenta, the two-nucleon momentum distribution n_A^{N_1N_2} (k_{rel}, K_{c.m.}, \theta) exhibits the property of factorization, namely n_A^{N_1N_2} (k_{rel}, K_{c.m.}, \theta) \simeq n_{rel}(k_{rel}) n_(c.m.)( K{c.m.}). The factorization of the momentum distributions , bearing a universal character, results from a general property of realistic nuclear wave functions, namely their factorization at short inter-nucleon separations. The factorization of the two-nucleon momentum distribution allows one to develop the correlated part of the nucleon spectral function P(k,E) in terms of a convolution integral involving the product of the many-body, parameter-free relative and c.m. momentum distributions of a given nucleus. It is shown that: (i) the obtained spectral function perfectly satisfies the momentum sum rule, i.e. when it is integrated over the removal energy E, it fully reproduces the momentum distributions obtained from realistic many-body wave functions , (ii) in order to saturate the momentum sum rule at high values of the momentum (k \simeq 5 fm^{-1}) the spectral function has to be integrate up to E \simeq 400 MeV. To sum up a realistic, parameter-free many-body Spectral function has been developed such that : i) a phenomenological convolution spectral function developed in the past is fully justified from a many-body point of view , and (ii) the model dependence which might be present in calculations of inclusive electroweak processes could be reduced by the use of the convolution spectral function developed here.Comment: 42 pages, 15 figure

A theoretical analysis of the relationship between social capital and corporate social responsibility: concepts and definitions

The paper studies the relationship between social capital (SC) and Corporate Social Responsibility (CSR) by investigating the idea of a virtuous circle, between the level of SC and the implementation of CSR practices, that fosters socio-economic development by generating social inclusion and social networks based on trust and trustworthiness. Following the literature on SC that stresses its multidimensional character, both a cognitive and a structural idea of SC are considered. The first one essentially refers to the dispositional characters of agents that affect their propensity to behave in different ways. The latter refers to social networks connecting agents. With regard to the concept of CSR, a contractarian approach is adopted and CSR is considered as an extended model of corporate governance, based on the fiduciary duties owed to all the firm’s stakeholders. Among stakeholders, a original distinction between “strong” and “weak” stakeholders is introduced. The key element that allows to distinguish between strong and weak stakeholders concerns the consequences that the break in the relationship with the firm produces both on the stakeholder and on the firm. Both these two categories have made specific investments in the firm. However, strong stakeholders are precious for the firm because they bring in strategic assets. On the contrary, weak stakeholders do not bring strategic assets into the firm and firms have material incentives at defecting in the relationship with them. Considering the notions of cognitive and structural SC, a contractarian approach to CSR and the distinction between weak and strong stakeholders, the paper shows that: a) the level of cognitive SC plays a key role in inducing the firm to adopt and observe CSR practices that respect all the stakeholders; b) the decision of adopting formal instruments of CSR contributes to create cognitive SC that is endogenously determined in the model; c) the level of cognitive SC and the decision of adopting CSR practices creates structural SC in terms of a long term relationship between the firm and the weak and strong stakeholders.Social capital, Corporate Social Responsibility, Social network, Ideal utility, Cooperation, Trust.