This title appears in the Scientific Report :
2020
Please use the identifier:
http://dx.doi.org/10.1016/j.nuclphysa.2018.09.052 in citations.
Please use the identifier: http://hdl.handle.net/2128/24544 in citations.
Multi-differential pattern of low-mass e+e− excess from s NN = 2.4 GeV Au+Au collisions with HADES
Multi-differential pattern of low-mass e+e− excess from s NN = 2.4 GeV Au+Au collisions with HADES
The matter formed in central heavy-ion collisions at a few GeV per nucleon is commonly understood as resonance matter, a gas of nucleons and excited baryon states with a substantial contribution from mesonic, mostly pionic excitations. Yet, in the initial phase of the reaction the system is compress...
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Personal Name(s): | Harabasz, Szymon |
---|---|
HADES Collaboration / Ritman, James (Corresponding author) | |
Contributing Institute: |
Experimentelle Hadronstruktur; IKP-1 |
Published in: |
Nuclear physics |
Imprint: |
Amsterdam
North-Holland Publ. Co.
2019
|
Physical Description: |
771-774 |
DOI: |
10.1016/j.nuclphysa.2018.09.052 |
Conference: | 27th International Conference on Ultrarelativistic Nucleus-Nucleus Collisions (Quark Matter), Venice (Italy), 2018-05-13 - 2018-05-19 |
Document Type: |
Contribution to a conference proceedings Journal Article |
Research Program: |
Cosmic Matter in the Laboratory |
Link: |
OpenAccess OpenAccess |
Publikationsportal JuSER |
Please use the identifier: http://hdl.handle.net/2128/24544 in citations.
The matter formed in central heavy-ion collisions at a few GeV per nucleon is commonly understood as resonance matter, a gas of nucleons and excited baryon states with a substantial contribution from mesonic, mostly pionic excitations. Yet, in the initial phase of the reaction the system is compressed to beyond nuclear ground state density and hence substantial modifications of the hadron properties are expected to occur. The spectral distribution of virtual photons measured in Au+Au collisions at 2.4 GeV center of mass energy indicates strong medium effects beyond pure superposition of individual NN collisions. We present multi-differential distributions of low-mass electron pairs. This radiation is remarkably well described assuming emission from a thermalized system. To gain deeper understanding of the microscopic origin of the radiation, we extracted the centrality dependent true (not blue-shifted) temperature, its azimuthal distribution, as well as mass-dependent effective slope parameter. Virtual photon spectra are confronted with available model calculations. |