2,969 research outputs found
Cosmic rays in magnetized intracluster plasma
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
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
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 â whether they be social movements, trade unions or professional groups â 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
The most recent data on the weighted transverse single spin asymmetry
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 and quarks is possible and is performed.
Comparisons with models are made. Based on the extracted Sivers functions,
predictions for 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
Recent data on the transverse single spin asymmetry measured by the
STAR Collaboration for 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
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