346,112 research outputs found
Status of the ANTARES Project
The ANTARES collaboration is constructing a neutrino telescope in the
Mediterranean Sea at a depth of 2400 metres, about 40 kilometres off the French
coast near Toulon. The detector will consist of 12 vertical strings anchored at
the sea bottom, each supporting 25 triplets of optical modules equipped with
photomultipliers, yielding sensitivity to neutrinos with energies above some 10
GeV. The effective detector area is roughly 0.1 square kilometres for neutrino
energies exceeding 10 TeV. The measurement of the Cherenkov light emitted by
muons produced in muon-neutrino charged-current interactions in water and
under-sea rock will permit the reconstruction of the neutrino direction with an
accuracy of better than 0.3 degrees at high energies. ANTARES will complement
the field of view of neutrino telescopes at the South Pole in the
low-background searches for point-sources of high-energy cosmic neutrinos and
will also be sensitive to neutrinos produced by WIMP annihilation in the Sun or
the Galactic centre.Comment: 3 pages, 3 figures, to appear in Proc. HEP2003 Europhysics Conf.,
Aachen, Germany, 17-23 July 200
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
Thermal hadron production in pp and p{\bar p} collisions
It is shown that the hadron production in high energy pp and p{\bar p}
collisions, calculated by assuming that particles originate in hadron gas
fireballs at thermal and partial chemical equilibrium, agrees very well with
the data. The temperature of the hadron gas fireballs, determined by fitting
hadron abundances, does not seem to depend on the centre of mass energy, having
a nearly constant value of about 170 MeV. This value is in agreement with that
obtained in e^+e^- collisions and supports a universal hadronization mechanism
in all kinds of reactions consisting in a parton-hadron transition at critical
values of temperature and pressure.Comment: 41 pages, 11 .eps figures, published in Z. Phys. C Revision -
Corrections of two formulae in Sect.
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
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