Low-momentum direct-photon measurement in Cu + Cu collisions at sNN =200 GeV
(2018) In Physical Review C 98(5).- Abstract
- We measured direct photons for pT<5GeV/c in minimum bias and 0%–40% most-central events at midrapidity for Cu+Cu collisions at √sNN=200GeV. The e+e− contribution from quasireal direct virtual photons has been determined as an excess over the known hadronic contributions in the e+e− mass distribution. A clear enhancement of photons over the binary scaled p+p fit is observed for pT<4GeV/c in Cu+Cu data. The pT spectra are consistent with the Au+Au data covering a similar number of participants. The inverse slopes of the exponential fits to the excess after subtraction of the p+p baseline are 285±53(stat)±57(syst)MeV/c and 333±72(stat)±45(syst)MeV/c for minimum bias and 0%–40% most-central events, respectively. The rapidity density,... (More)
- We measured direct photons for pT<5GeV/c in minimum bias and 0%–40% most-central events at midrapidity for Cu+Cu collisions at √sNN=200GeV. The e+e− contribution from quasireal direct virtual photons has been determined as an excess over the known hadronic contributions in the e+e− mass distribution. A clear enhancement of photons over the binary scaled p+p fit is observed for pT<4GeV/c in Cu+Cu data. The pT spectra are consistent with the Au+Au data covering a similar number of participants. The inverse slopes of the exponential fits to the excess after subtraction of the p+p baseline are 285±53(stat)±57(syst)MeV/c and 333±72(stat)±45(syst)MeV/c for minimum bias and 0%–40% most-central events, respectively. The rapidity density, dN/dy, of photons demonstrates the same power law as a function of dNch/dη observed in Au+Au at the same collision energy. (Less)
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https://lup.lub.lu.se/record/083a1e0b-bb22-41ce-8f94-d32b1489cd34
- author
- Adare, A. ; Gustafsson, Hans-Åke LU ; Haslum, Eva LU ; Oskarsson, Anders LU ; Rosendahl, Sarah LU ; Silvermyr, David LU ; Stenlund, Evert LU and Zou, L.
- author collaboration
- organization
- publishing date
- 2018
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Physical Review C
- volume
- 98
- issue
- 5
- article number
- 054902
- publisher
- American Physical Society
- external identifiers
-
- scopus:85057133067
- ISSN
- 2469-9985
- DOI
- 10.1103/PhysRevC.98.054902
- language
- English
- LU publication?
- yes
- additional info
- Export Date: 4 December 2018
- id
- 083a1e0b-bb22-41ce-8f94-d32b1489cd34
- date added to LUP
- 2018-12-04 08:49:45
- date last changed
- 2023-04-08 23:52:49
@article{083a1e0b-bb22-41ce-8f94-d32b1489cd34, abstract = {{We measured direct photons for pT<5GeV/c in minimum bias and 0%–40% most-central events at midrapidity for Cu+Cu collisions at √sNN=200GeV. The e+e− contribution from quasireal direct virtual photons has been determined as an excess over the known hadronic contributions in the e+e− mass distribution. A clear enhancement of photons over the binary scaled p+p fit is observed for pT<4GeV/c in Cu+Cu data. The pT spectra are consistent with the Au+Au data covering a similar number of participants. The inverse slopes of the exponential fits to the excess after subtraction of the p+p baseline are 285±53(stat)±57(syst)MeV/c and 333±72(stat)±45(syst)MeV/c for minimum bias and 0%–40% most-central events, respectively. The rapidity density, dN/dy, of photons demonstrates the same power law as a function of dNch/dη observed in Au+Au at the same collision energy.}}, author = {{Adare, A. and Gustafsson, Hans-Åke and Haslum, Eva and Oskarsson, Anders and Rosendahl, Sarah and Silvermyr, David and Stenlund, Evert and Zou, L.}}, issn = {{2469-9985}}, language = {{eng}}, number = {{5}}, publisher = {{American Physical Society}}, series = {{Physical Review C}}, title = {{Low-momentum direct-photon measurement in Cu + Cu collisions at sNN =200 GeV}}, url = {{http://dx.doi.org/10.1103/PhysRevC.98.054902}}, doi = {{10.1103/PhysRevC.98.054902}}, volume = {{98}}, year = {{2018}}, }