The study of dilepton production in heavy-ion collisions at the CERN SPS provided some of the most interesting observations done so far in the search for the quark gluon plasma. However, several ...aspects of the understanding of these measurements need to be clarified. For example, the study of the J/$\psi$ production in different colliding systems should help to distangle which is the variable driving the J/$_psi$ suppression. The NA60 experiment, with a new radiation tolerant Silicon pixel detector, studied Indium-Indium interactions in the year 2003. In this paper, we present the J/$\psi$/DY ratio, integrated over all the centralities of the collisions, together with a first study of the J/$\psi$ transverse momentum and polarization.
The NA60 silicon pixel telescope Keil, M.; Arnaldi, R.; Banicz, K. ...
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment,
09/2005, Letnik:
549, Številka:
1
Journal Article, Conference Proceeding
Recenzirano
The NA60 experiment studies the production of open charm and prompt dimuons in proton–nucleus and nucleus–nucleus collisions at the CERN SPS. The main goal of NA60 is the study of various possible ...signatures of the transition from hadronic to deconfined partonic matter, e.g. anomalous charmonium suppression, dimuons from thermal radiation and modifications of vector meson properties. Reaching these goals is facilitated by the use of new state-of-the-art silicon detectors in the vertex region.
Downstream of the target and inside a 2.5
T dipole magnetic field a pixel telescope measures the charged tracks originating from the collisions. The full pixel telescope consists of 16 planes with 96 ALICE1LHCb pixel detector assemblies in total. This paper describes the setup of the pixel telescope, results from tests as well as the expected implications of the operation of the silicon detectors in the harsh radiation environment of the NA60 experiment, with heavy-ion collisions.
The response of the Euroball Cluster detector to γ-radiation up to 10 MeV Wilhelm, M.; Eberth, J.; Pascovici, G. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
11/1996, Letnik:
381, Številka:
2
Journal Article
Recenzirano
The Euroball Cluster detector consists of seven closely packed hexagonal encapsulated germanium detectors which are mounted in a common cryostat and surrounded by a BGO suppression shield. By adding ...back the Compton scattered events between the seven germanium detectors the detector system behaves similar as a single germanium detector with a volume of 2000 cm
3. The response of this very large germanium detector to γ-rays up to 10 MeV has been measured using a short lived
24Al source produced at the Cologne FN Tandem accelerator. At 10 MeV the efficiency of the Cluster detector is nearly one order of magnitude larger than that of a 30% germanium detector.
The NA60 experiment at the CERN SPS has studied low-mass dimuon production in 158A GeV In-In collisions. An excess of pairs above the known meson decays has been reported before. We now present ...precision results on the associated transverse momentum spectra. The slope parameter Teff extracted from the spectra rises with dimuon mass up to the rho, followed by a sudden decline above. While the initial rise is consistent with the expectations for radial flow of a hadronic decay source, the decline signals a transition to an emission source with much smaller flow. This may well represent the first direct evidence for thermal radiation of partonic origin in nuclear collisions.
The NA60 experiment studied low-mass muon pair production in proton–nucleus (p–A) collisions using a 400 GeV proton beam at the CERN SPS. The low-mass dimuon spectrum is well described by the ...superposition of the two-body and Dalitz decays of the light neutral mesons η, ρ, ω, η′ and ϕ, and no evidence of in-medium effects is found. A new high-precision measurement of the electromagnetic transition form factors of the η and ω was performed, profiting from a 10 times larger data sample than the peripheral In–In sample previously collected by NA60. Using the pole-parameterisation |F(M)|2=(1−M2/Λ2)−2 we find Λη−2=1.934±0.067 (stat.) ±0.050 (syst.) (GeV/c2)−2 and Λω−2=2.223±0.026 (stat.) ±0.037 (syst.) (GeV/c2)−2. An improved value of the branching ratio of the Dalitz decay ω→μ+μ−π0 is also obtained, with BR(ω→μ+μ−π0)=1.41±0.09 (stat.)±0.15 (syst.)×10−4. Further results refer to the ρ line shape and a new limit on ρ/ω interference in hadron interactions.
The NA60 experiment studied low-mass muon pair production in proton–nucleus (p–A) collisions using a 400 GeV proton beam at the CERN SPS. The low-mass dimuon spectrum is well described by the ...superposition of the two-body and Dalitz decays of the light neutral mesons η , ρ , ω , η′ and ϕ , and no evidence of in-medium effects is found. A new high-precision measurement of the electromagnetic transition form factors of the η and ω was performed, profiting from a 10 times larger data sample than the peripheral In–In sample previously collected by NA60. Using the pole-parameterisation |F(M)|2=(1−M2/Λ2)−2 we find Λη−2=1.934±0.067 (stat.) ±0.050 (syst.) (GeV/c2)−2 and Λω−2=2.223±0.026 (stat.) ±0.037 (syst.) (GeV/c2)−2 . An improved value of the branching ratio of the Dalitz decay ω→μ+μ−π0 is also obtained, with BR(ω→μ+μ−π0)=1.41±0.09 (stat.)±0.15 (syst.)×10−4 . Further results refer to the ρ line shape and a new limit on ρ/ω interference in hadron interactions.
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