6,742 research outputs found
Azimuthal and transverse single spin asymmetries in hadronic collisions
We give a short overview of the phenomenology of azimuthal and transverse
single spin asymmetries in (un)polarized high-energy hadronic collisions. We
briefly summarize a transverse momentum dependent, generalized parton model
approach to these polarization phenomena, and discuss some of its applications.
Finally, open points and future developments will be outlined.Comment: 8 pages; Talk given at the "5th International Workshop on Quantum
Chromodynamics - Theory and Experiment (QCD@Work 2010)", 20-23 June 2010,
Martina Franca, Valle d'Itria, Italy; to be published in the AIP Conference
Proceedings Serie
Transverse Momentum Dependent Distributions in Hadronic Collisions: p(transv. polarized) p --> D + X and p(transv. polarized) p --> gamma + X
Our understanding of the transverse spin structure of hadrons might
definitely get improved by the information we gather on transverse momentum
dependent (TMD) distributions. These new functions could also be crucial for a
description of the observed transverse single spin asymmetries (SSA). In a hard
scattering model for inclusive hadronic reactions, based on a generalized QCD
factorization scheme, many mechanisms - namely the Sivers, Collins,
Boer-Mulders effects - might contribute to a SSA. We show how the k_T dependent
phases arising from the partonic kinematics together with a suitable choice of
experimental configurations could help in disentangling the above mentioned
effects. We discuss their potential role in two inclusive hadronic processes:
heavy meson and photon production in pp and p pbar collisions.Comment: LaTeX 2e, 4 pages, 4 ps figures, uses aipproc.cls. Talk delivered by
U. D'Alesio at the "17th International Spin Physics Symposium", SPIN2006,
October 2-7, 2006, Kyoto, Japa
Parton intrinsic motion: unpolarized cross sections and the Sivers effect in inclusive particle production
We present a detailed study, performed in the framework of LO perturbative
QCD with the inclusion of spin and k_T effects, of unpolarized cross sections
for the Drell-Yan process and for inclusive pion and photon production in
hadronic collisions, in different kinematical situations. We find a
satisfactory agreement between theoretical predictions and experimental data.
This supports the study of spin effects and transverse single spin asymmetries
(SSA) within the same scheme. We then present results for SSA, generated by the
so-called Sivers effect, in inclusive pion production in proton-proton
collisions.Comment: LaTeX2e, 4 pages, 4 ps figures, uses ws-procs9x6. Talk delivered by
F. Murgia at the ``16th International Spin Physics Symposium'', SPIN2004,
October 10-16, 2004, Trieste, Ital
Phenomenology of single transverse spin asymmetries
A unified and consistent phenomenological approach to single transverse spin
asymmetries in the framework of perturbative QCD, with the inclusion of a new
class of spin and k_T dependent distribution and fragmentation functions, is
presented. As an example, results on A_N(p(pol) p --> pion X) and P_Lambda(p p
-->Lambda(pol) X) are shown.Comment: 8 pages, 3 figures, uses epsfig.sty. Talk delivered by U. D'Alesio at
the ``VIII Convegno su Problemi di Fisica Nucleare Teorica'', October 18-20,
2000, Cortona, Ital
Single spin asymmetries, unpolarized cross sections and the role of partonic transverse momentum
Partonic intrinsic transverse momentum can be essential for the explanation
of large single spin asymmetries in hadronic reactions in the framework of
perturbative QCD. The status of an ongoing program investigating in a
consistent way the role of intrinsic transverse momentum both in unpolarized
and polarized processes is discussed. We compute inclusive cross sections for
hadron and photon production in hadronic collisions and for Drell-Yan
processes; the results are compared with available experimental data in several
different kinematical situations.Comment: LaTeX, 6 pages, 4 ps figures, uses graphicx.sty. Talk delivered by U.
D'Alesio at the ``15th International Spin Physics Symposium'', SPIN2002,
September 9-14, 2002, Brookhaven National Laboratory, Upton (NY), US
Cross sections and single spin asymmetries in hadronic collisions with intrinsic transverse momentum effects
The role of intrinsic transverse momentum both in unpolarized and polarized
processes is discussed. We consider inclusive cross sections for pion
production in hadronic collisions and for Drell-Yan processes; the results are
compared with available experimental data in several different kinematical
situations. We reanalyze transverse single spin asymmetries (SSA) observed in
inclusive pion production, p(transv. polarized) p --> pion + X, in terms of
Sivers effect and show how it can be disentangled in polarized Drell-Yan
processes by suitably integrating over some final configurations. Estimates for
RHIC experiments are given.Comment: LaTeX, 8 pages, 4 ps figures, uses epsfig.sty. Talk delivered by F.
Murgia at the "IX Convegno su Problemi di Fisica Nucleare Teorica", October
9-12, 2002, Cortona, Ital
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
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