Records |
Author |
HADES Collaboration (Agakishiev, G. et al); Diaz, J.; Gil, A. |
Title |
Origin of the low-mass electron pair excess in light nucleus-nucleus collisions |
Type |
Journal Article |
Year |
2010 |
Publication  |
Physics Letters B |
Abbreviated Journal |
Phys. Lett. B |
Volume |
690 |
Issue |
2 |
Pages |
118-122 |
Keywords |
Virtual bremsstrahlung; Dileptons; Nucleon-nucleon collisions |
Abstract |
We report measurements of electron pair production in elementary p + p and d + p reactions at 1.25 GeV/mu with the HADES spectrometer. For the first time, the electron pairs were reconstructed for n + p reactions by detecting the proton spectator from the deuteron breakup. We find that the yield of electron pairs with invariant mass Me+e- > 0.15 GeV/c(2) is about an order of magnitude larger in n + p reactions as compared to p + p. A comparison to model calculations demonstrates that the production mechanism is not sufficiently described yet. The electron pair spectra measured in C + C reactions are compatible with a superposition of elementary n + p and p + p collisions, leaving little room for additional electron pair sources in such light collision systems. |
Address |
[Froehlich, I.; Galatyuk, T.; Goebel, K.; Lorenz, M.; Markert, J.; Michel, J.; Muentz, C.; Pachmayer, Y. C.; Stroebele, H.; Stroth, J.; Sturm, C.; Tarantola, A.; Teilab, K.] Goethe Univ Frankfurt, Inst Kernphys, D-60438 Frankfurt, Germany, Email: t.galatyuk@gsi.de |
Corporate Author |
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Thesis |
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Publisher |
Elsevier Science Bv |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0370-2693 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
ISI:000279513800003 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ elepoucu @ |
Serial |
413 |
Permanent link to this record |
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Author |
HADES Collaboration (Agakishiev, G. et al); Diaz, J.; Gil, A. |
Title |
Study of the quasi-free np -> np pi(+)pi(-) reaction with a deuterium beam at 1.25 GeV/nucleon |
Type |
Journal Article |
Year |
2015 |
Publication  |
Physics Letters B |
Abbreviated Journal |
Phys. Lett. B |
Volume |
750 |
Issue |
|
Pages |
184-193 |
Keywords |
Two-pion production; np collisions; Resonance excitations |
Abstract |
The tagged quasi-free np -> np pi(+)pi(-) reaction has been studied experimentally with the High Acceptance Di-Electron Spectrometer (HADES) at GSI at a deuteron incident beam energy of 1.25 GeV/nucleon (root S similar to 2.42 GeV/c for the quasi-free collision). For the first time, differential distributions of solid statistics for pi(+)pi(-) production in np collisions have been collected in the region corresponding to the large transverse momenta of the secondary particles. The invariant mass and angular distributions for the np -> np pi(+)pi(-) reaction are compared with different models. This comparison confirms the dominance of the t-channel with Delta Delta contribution. It also validates the changes previously introduced in the Valencia model to describe two-pion production data in other isospin channels, although some deviations are observed, especially for the pi(+)pi(-) invariant mass spectrum. The extracted total cross section is also in much better agreement with this model. Our new measurement puts useful constraints for the existence of the conjectured dibaryon resonance at mass M similar to 2.38 GeV and with width Gamma similar to 70 MeV. (C) 2015 The Authors. Published by Elsevier B.V. |
Address |
[Finocchiaro, P.] Ist Nazl Fis Nucl, Lab Nazl Sud, I-95125 Catania, Italy, Email: akurilkin@jinr.ru; |
Corporate Author |
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Thesis |
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Publisher |
Elsevier Science Bv |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0370-2693 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000364250600031 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
2469 |
Permanent link to this record |
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Author |
NEXT Collaboration (Henriques, C.A.O. et al); Gomez-Cadenas, J.J.; Alvarez, V.; Benlloch-Rodriguez, J.; Botas, A.; Carcel, S.; Carrion, J.V.; Diaz, J.; Felkai, R.; Ferrario, P.; Laing, A.; Liubarsky, I.; Lopez-March, N.; Martin-Albo, J.; Martinez, A.; Muñoz Vidal, J.; Musti, M.; Nebot-Guinot, M.; Novella, P.; Palmeiro, B.; Perez, J.; Querol, M.; Renner, J.; Rodriguez, J.; Serra, L.; Simon, A.; Sorel, M.; Torrent, J.; Yahlali, N. |
Title |
Secondary scintillation yield of xenon with sub-percent levels of CO2 additive for rare-event detection |
Type |
Journal Article |
Year |
2017 |
Publication  |
Physics Letters B |
Abbreviated Journal |
Phys. Lett. B |
Volume |
773 |
Issue |
|
Pages |
663-671 |
Keywords |
Double beta decay; Neutrino; Rare event detection; Electroluminescence; Secondary scintillation; Xenon |
Abstract |
Xe-CO2 mixtures are important alternatives to pure xenon in Time Projection Chambers (TPC) based on secondary scintillation (electroluminescence) signal amplification with applications in the important field of rare event detection such as directional dark matter, double electron capture and double beta decay detection. The addition of CO2 to pure xenon at the level of 0.05-0.1% can reduce significantly the scale of electron diffusion from 10 mm/root m to 2.5 mm/root m, with high impact on the discrimination of the events through pattern recognition of the topology of primary ionization trails. We have measured the electroluminescence (EL) yield of Xe-CO2 mixtures, with sub-percent CO2 concentrations. We demonstrate that the EL production is still high in these mixtures, 70% and 35% relative to that produced in pure xenon, for CO2 concentrations around 0.05% and 0.1%, respectively. The contribution of the statistical fluctuations in EL production to the energy resolution increases with increasing CO2 concentration, being smaller than the contribution of the Fano factor for concentrations below 0.1% CO2. |
Address |
[Henriques, C. A. O.; Freitas, E. D. C.; Mano, R. D. P.; Jorge, M. R.; Fernandes, L. M. P.; Monteiro, C. M. B.; dos Santos, J. M. F.] Univ Coimbra, Phys Dept, LIBPhys, Rua Larga, P-3004516 Coimbra, Portugal, Email: cristina@gian.fis.uc.pt |
Corporate Author |
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Thesis |
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Publisher |
Elsevier Science Bv |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0370-2693 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000413294200099 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
3342 |
Permanent link to this record |
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Author |
HADES Collaboration (Lapidus, K. et al); Diaz, J.; Gil, A. |
Title |
The HADES-at-FAIR project |
Type |
Journal Article |
Year |
2012 |
Publication  |
Physics of Atomic Nuclei |
Abbreviated Journal |
Phys. Atom. Nuclei |
Volume |
75 |
Issue |
5 |
Pages |
589-593 |
Keywords |
|
Abstract |
After the completion of the experimental program at SIS18 the HADES setup will migrate to FAIR, where it will deliver high-quality data for heavy-ion collisions in an unexplored energy range of up to 8 A GeV. In this contribution, we briefly present the physics case, relevant detector characteristics and discuss the recently completed upgrade of HADES. |
Address |
[Lapidus, K.; Chen, J. C.; Epple, E.; Fabbietti, L.; Lalik, R.; Muenzer, R.; Schmah, A.; Siebenson, J.] Excellence Cluster Origin & Struct Universe, Garching, Germany, Email: kirill.lapidus@ph.tum.de |
Corporate Author |
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Thesis |
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Publisher |
Maik Nauka/Interperiodica/Springer |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
ISSN |
1063-7788 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
|
Notes |
WOS:000304621800011 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
1046 |
Permanent link to this record |