One of the main goals of the HADES experiment is to achieve a detailed understanding of dielectron emission from hadronic systems at moderate bombarding energies. Results obtained on electron pair ...production in elementary
N+
N collisions pave the way to a better understanding of the origin of the pair excess seen in heavy-ion collisions. This puzzling excess, reported first by the former DLS experiment, is now being investigated systematically by HADES.
The emission of e+e− pairs from C+C collisions at an incident energy of 1 GeV per nucleon has been investigated. The measured production probabilities, spanning from the π0-Dalitz to the ρ/ω ...invariant-mass region, display a strong excess above the cocktail of standard hadronic sources. The bombarding-energy dependence of this excess is found to scale like pion production, rather than like eta production. The data are in good agreement with results obtained in the former DLS experiment.
A sectioned spectrometer of fast neutrons Abdurashitov, D. N.; Gavrin, V. N.; Matushko, V. L. ...
Instruments and experimental techniques (New York),
2009/1, Letnik:
52, Številka:
1
Journal Article
Recenzirano
Development of a capture gated spectrometer on the basis of a liquid organic scintillator doped with enriched
6
Li is discussed. Particular interest is evoked by the good pulse height resolution of ...the spectrometer for 14-MeV neutrons, which is expected to be very high, ∼10–15%. This resolution is attained by compensating for the nonlinearity of the light yield in the scintillator owing to the use of separate optically isolated sections, which independently detect scintillations from each recoil proton. The detector is sensitive to fluence rates ranging from 10
−4
to 10
2
cm
−2
s
−1
above a threshold of 500 keV under conditions of uncorrelated γ-ray background at a level of up to 10
2
s
−1
(
E
> 100 keV). A pilot model of the detector based on a scintillator without a lithium dopant has been produced and tested. The detector efficiency is governed by the scintillator volume (∼1.2 l); for 3-MeV neutrons, its value is 0.2–0.5%. The response of the pilot detector to neutrons from a Pu-α-Be source with energies of up to 10 MeV has been measured. Initial testing indicates a low threshold at an ∼600-keV energy of a recoil proton. A good spectral response is obtained using the criterion that three optical sections of the detector operate at a time. This spectrometer can find application in low-background experiments in basic physics research, as well as in space research and nuclear medicine for measuring the parameters of the neutron flux.
Dielectron spectroscopy at 1-2 AGeV with HADES Spataro, S.; Agodi, C.; Belver, D. ...
European physical journal. A, Hadrons and nuclei (Print),
11/2008, Letnik:
38, Številka:
2
Journal Article, Conference Proceeding
Recenzirano
The HADES spectrometer at GSI (Darmstadt) is investigating the
e
+
e
-
pair production in p+p,
p
+
A
and
A
+
A
collisions. In this contribution we would like to highlight the physics motivations and ...the experiments performed so far, focusing mainly on the first results coming from
12
C +
12
C collisions at 1 and 2AGeV, and on preliminary results from
p
+
p
/
d
+
p
collisions at 1.25AGeV.
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