2,874 research outputs found

    Cosmic rays in magnetized intracluster plasma

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    Recent results are reported on Magnetic Fields in Clusters of Galaxies, Diffuse Radio Emission, and Radio - X-ray connection in Radio Halos.Comment: 2 pages, 1 figure, Invited talk at the JD15 "Magnetic Fields in Diffuse Media", IAU XXVII General Assembly, Rio de Janeir

    Non-Standard Time Reversal for Particle Multiplets and the Spin-Flavor Structure of Hadrons

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    We show that a system of quarks interacting with chiral fields provides a physical representation of a ``non-standard'' time reversal for particle multiplets proposed by Weinberg. As an application, we argue that, if the internal structure of hadrons is described by a chiral lagrangian, the so-called time-reversal-odd quark distribution functions might not be forbidden by time-reversal invariance.Comment: 2 pages, proceedings of "The Spin Structure of the Proton", ECT - Trento, July 2001. Eds. S Bass, A De Roeck and A Deshpand

    Representations of Precarity in Italy

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    This contribution is focused on collective and individual stories of precarity in Italy. At the present time, when work and the imaginaries socially constructed around it are more and more individualised and fragmented, imaginaries and collective references – whether they be social movements, trade unions or professional groups – have given way to ever more particularistic and singular experiences, which hinder the construction of a coherent identity for workers. In this scenario the question to be asked is then: how is it possible to elaborate a new collective imaginary of precarity and reclaim new rights? After a focus on the phenomenon of precarity in Italy, this contribution move to consider the activities of the network of San Precario, a cultural phenomenon that managed to develop new kinds of social claims based on bottom-up and horizontal practices. It is then discussed that the current return to an almost exclusively individual approach to the question of precarity, which forces subjects to bear the management of their professional life trajectories. Finally, an analysis of social movements' recent efforts of self-organisation and some reflections on the possible role of social sciences in elaborating tools for planning a renewed welfare system are offere

    Extracting the Sivers function from polarized SIDIS data and making predictions

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    The most recent data on the weighted transverse single spin asymmetry AUTsin⁥(ϕh−ϕS)A_{UT}^{\sin(\phi_h-\phi_S)} from HERMES and COMPASS collaborations are analysed within LO parton model with unintegrated parton distribution and fragmentation functions; all transverse motions are taken into account, with exact kinematics, in the elementary interactions. The overall quality of the data is such that, for the first time, a rather well constrained extraction of the Sivers function for uu and dd quarks is possible and is performed. Comparisons with models are made. Based on the extracted Sivers functions, predictions for AUTsin⁥(ϕh−ϕS)A_{UT}^{\sin(\phi_h-\phi_S)} asymmetries at JLab are given; suggestions for further measurements at COMPASS, with a transversely polarized hydrogen target and selecting favourable kinematical ranges, are discussed. Predictions are also presented for Single Spin Asymmetries (SSA) in Drell-Yan processes at RHIC and GSI.Comment: 18 pages, 10 figures, version published in PRD, one figure and comments adde

    Study of the sign change of the Sivers function from STAR Collaboration W/Z production data

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    Recent data on the transverse single spin asymmetry ANA_N measured by the STAR Collaboration for p↑ p→W±/Z0 Xp^\uparrow \, p \to W^\pm/Z^0 \, X reactions at RHIC allow the first investigation of the Sivers function in Drell-Yan processes and of its expected sign change with respect to SIDIS processes. A new extraction of the Sivers functions from the latest SIDIS data is performed and a critical assessment of the significance of the STAR data is attempted.Comment: 17 pages, 16 pdf figures, uses jheppub.st