6,051 research outputs found
Results on angular distributions of thermal dileptons in nuclear collisions
The NA60 experiment at the CERN SPS has studied dimuon production in 158 AGeV
In-In collisions. The strong pair excess above the known sources found in the
mass region GeV has been previously interpreted as thermal
radiation. In this paper results on the associated angular distributions for
GeV, as measured in the Collins-Soper reference frame, are presented. The
structure function parameters , , are consistent with zero
and the projected polar and azimuth angle distributions are uniform. The
absence of any polarization is consistent with the interpretation of the excess
dimuons as thermal radiation from a randomized system.Comment: 4 pages, 4 figures - To appear in the conference proceedings for
Quark Matter 2009, March 30 - April 4, Knoxville, Tennesse
J/psi production in p-A and A-A collisions at fixed target experiments
Charmonia suppression is one of the main signatures for the formation of a
deconfined medium. However, also nuclear effects, not related to the production
of a hot medium, can affect the J/psi yield. The determination, from the study
of p-A collisions, of the J/psi behaviour in nuclear matter is, therefore,
extremely important to correctly quantify the amount of charmonia suppression
induced by the deconfined medium. In this paper the new NA60 results collected
at 158 GeV incident energy, i.e. under the same kinematical conditions as the
In-In (NA60) and Pb-Pb (NA50) data, are presented and compared with p-A
measurements from other fixed target experiments. Results on A-A collisions are
also reviewed taking into account the new available information on the
influence of cold nuclear matter on the J/psi production yield. Finally,
results on the J/psi polarization are shown for p-A and A-A collisions.Comment: 8 pages, 8 figures - To appear in the conference proceedings for
Quark Matter 2009, March 30 - April 4, Knoxville, Tennesse
J/Psi and Psi(2S) production in Pb-Pb collisions with the ALICE Muon Spectrometer at the LHC
Charmonium states are considered important signatures of the strongly
interacting medium created in heavy-ion collisions. In the ALICE experiment,
these probes can be investigated in the mu^+mu^- decay channel, in the forward
rapidity region (2.5<y<4) down to zero transverse momentum. Results on
charmonia production in Pb-Pb collisions at sqrt(s_NN)=2.76 TeV are presented.
The centrality and transverse momentum dependence of the inclusive J/Psi
nuclear modification factor are shown and compared with theoretical models.
Finally, first ALICE results on the Psi(2S) production in Pb-Pb collisions are
also discussed.Comment: 4 pages, 4 figures, contribution to the proceedings of the Quark
Matter 2012 International Conference, Washington D.C., August 13-18, 201
Dileptons and Direct Photons at SPS
The study of dilepton and direct photon emission was one of the main topics
of the experimental program at the SPS devoted to the search of signals for QGP
formation. Three generations of experiments, Helios-3, NA38/NA50, CERES and
NA60 measured e+e- or mu+mu- production in various colliding systems and at
different energies. While lepton pair production in p-A collisions was found to
be reasonably well described by the expected sources, all experiments observed
in nuclear collisions an excess of the yield above the extrapolation from p-A.
As a result of this joint experimental effort we have currently a large amount
of information characterizing this excess: its mass spectrum over the full
range from 0.2 GeV/c^2 up to the J/psi, its transverse momentum spectra
including their mass dependence, its angular distributions, its dependence on
collision centrality over the complete range etc. Putting together all this
information leads to the conclusion that what we observe is the long-sought
thermal radiation from the fireball.Comment: 8 pages, 6 figures - To appear in the conference proceedings for
Quark Matter 2009, March 30 - April 4, Knoxville, Tennesse
Responsible Research and Innovation between \u201cnew governance\u201d and fundamental rights
This chapter frames RRI as an emerging governance approach in the EU regulatory context. We argue that reference to fundamental rights makes RRI a distinctive approach to responsibility compared to other existing paradigms and that human rights, in particular those laid down in the Charter of Fundamental Rights of the European Union, are not necessarily a constraint but can instead be a catalyst of innovation. Eventually we maintain that a governance framework based on the complementarity between legal norms and voluntary commitments might successfully combine the respect of fundamental rights with the openness and flexibility of the innovation process
Virtual Environments for Training: From Individual Learning to Collaboration with Humanoids
The next generation of virtual environments for training is oriented towards
collaborative aspects. Therefore, we have decided to enhance our platform for
virtual training environments, adding collaboration opportunities and
integrating humanoids. In this paper we put forward a model of humanoid that
suits both virtual humans and representations of real users, according to
collaborative training activities. We suggest adaptations to the scenario model
of our platform making it possible to write collaborative procedures. We
introduce a mechanism of action selection made up of a global repartition and
an individual choice. These models are currently being integrated and validated
in GVT, a virtual training tool for maintenance of military equipments,
developed in collaboration with the French company NEXTER-Group
The Muon Spectrometer of the ALICE experiment
The main goal of the Muon Spectrometer of the ALICE experiment is the
measurement of heavy quarks in pp, pA and AA collisions at LHC energies, via
the muonic channel. Physics motivations, the apparatus and its physics
performances are presented in this talk.Comment: 5 pages, 4 figures. Talk presented in Phase transitions in strongly
interacting matter Prague, 23.8.-29.8. 2004 18th Nuclear Physics Division
Conference of the EPS (NPDC18) Europhysics Conferenc
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