Dielectron production in C12+C12 collisions at 2AGeV with the HADES spectrometer

Krücken, R.; Agakichiev, G.; Agodi, C.; Alvarez-Poll, H.; Bałanda, A.; Bertini, D.; Bielčík, Jaroslav; Bellia, G.; Böhmer, M.; Bokemeyer, H.; Boyard, J. L.; Braun-Munzinger, P.; Cabanelas, Pablo; Chernenko, S.; Christ, T.; Coniglione, R.; Cosentino, L.; Diáz, J.; Dohrmann, F.; Durán, I.; Eberl, T.; Enghardt, W.; Fabbietti, L.; Fateev, O.; Fernandez, C.; Finocchiaro, P.; Friese, J.; Fröhlich, I.; Fuentes, B.; Garabatos, Chilo; Garzón, J. A.; Gernhäuser, R.; Gilardi, C.; Golubeva, M.; González-Díaz, D.; Grosse, E.; Guber, F.; Hennino, T.; Hlavac, S.; Holzmann, R.; Homolka, J.; Ierusalimov, A.; Iori, I.; Ivashkin, A.; Jaskuła, M.; Jurkovic, M.; Kagarlis, M.; Kajetanowicz, M.; Kämpfer, B.; Kanaki, K.; Karavicheva, T.; Kastenmüller, A.; Kidoń, L.; Kienle, P.; Koenig, I.; Koenig, W.; Körner, H. J.; Kolb, B. W.; Kotte, R.; Kugler, A.; Kühn, W.; Kulessa, R.; Kurepin, A.; Lang, S.; Lange, S.; Lehnert, J.; Lins, E.; Magestro, D.; Maiolino, C.; Malarz, A.; Markert, J.; Metag, V.; Mousa, J.; Münch, M.; Müntz, C.; Naumann, L.; Nekhaev, A.; Novotny, J.; Otwinowski, J.; Pachmayer, Y. C.; Pechenov, V.; Pérez, T.; Piattelli, P.; Pietraszko, J.; Pleskac, R.; Płoskoń, M.; Pospísil, V.; Prokopowicz, W.; Przygoda, W.; Ramstein, B.; Reshetin, A.; Ritman, J.; Roy-Stephan, M.; Rustamov, A.; Sadovsky, A.; Sailer, B.; Salabura, P.; Sánchez, M.; Sapienza, P.; Schmah, A.; Schön, H.; Schön, W.; Schröder, C.; Schwab, E.; Simon, R. S.; Smolyankin, V.; Smykov, L.; Spataro, S.; Spruck, B.; Ströbele, H.; Stroth, J.; Sturm, C.; Sudoł, M.; Suk, M.; Taranenko, A.; Tlusty, P.; Toia, A.; Traxler, M.; Tsertos, Haralambos; Vassiliev, D.; Vázquez, A.; Wagner, V.; Waluś, W.; Wiśniowski, M.; Wójcik, T.; Wüstenfeld, J.; Zanevsky, Y.; Zeitelhack, K.; Zovinec, D.; Zumbruch, P.

doi:10.1103/PhysRevLett.98.052302

Article

Date

2007

Author

Krücken, R.
Agakichiev, G.
Agodi, C.
Alvarez-Poll, H.
Bałanda, A.
Bertini, D.
Bielčík, Jaroslav
Bellia, G.
Böhmer, M.
Bokemeyer, H.
Boyard, J. L.
Braun-Munzinger, P.
Cabanelas, Pablo
Chernenko, S.
Christ, T.
Coniglione, R.
Cosentino, L.
Diáz, J.
Dohrmann, F.
Durán, I.
Eberl, T.
Enghardt, W.
Fabbietti, L.
Fateev, O.
Fernandez, C.
Finocchiaro, P.
Friese, J.
Fröhlich, I.
Fuentes, B.
Garabatos, Chilo
Garzón, J. A.
Gernhäuser, R.
Gilardi, C.
Golubeva, M.
González-Díaz, D.
Grosse, E.
Guber, F.
Hennino, T.
Hlavac, S.
Holzmann, R.
Homolka, J.
Ierusalimov, A.
Iori, I.
Ivashkin, A.
Jaskuła, M.
Jurkovic, M.
Kagarlis, M.
Kajetanowicz, M.
Kämpfer, B.
Kanaki, K.
Karavicheva, T.
Kastenmüller, A.
Kidoń, L.
Kienle, P.
Koenig, I.
Koenig, W.
Körner, H. J.
Kolb, B. W.
Kotte, R.
Kugler, A.
Kühn, W.
Kulessa, R.
Kurepin, A.
Lang, S.
Lange, S.
Lehnert, J.
Lins, E.
Magestro, D.
Maiolino, C.
Malarz, A.
Markert, J.
Metag, V.
Mousa, J.
Münch, M.
Müntz, C.
Naumann, L.
Nekhaev, A.
Novotny, J.
Otwinowski, J.
Pachmayer, Y. C.
Pechenov, V.
Pérez, T.
Piattelli, P.
Pietraszko, J.
Pleskac, R.
Płoskoń, M.
Pospísil, V.
Prokopowicz, W.
Przygoda, W.
Ramstein, B.
Reshetin, A.
Ritman, J.
Roy-Stephan, M.
Rustamov, A.
Sadovsky, A.
Sailer, B.
Salabura, P.
Sánchez, M.
Sapienza, P.
Schmah, A.
Schön, H.
Schön, W.
Schröder, C.
Schwab, E.
Simon, R. S.
Smolyankin, V.
Smykov, L.
Spataro, S.
Spruck, B.
Ströbele, H.
Stroth, J.
Sturm, C.
Sudoł, M.
Suk, M.
Taranenko, A.
Tlusty, P.
Toia, A.
Traxler, M.

Tsertos, Haralambos
Vassiliev, D.
Vázquez, A.
Wagner, V.
Waluś, W.
Wiśniowski, M.
Wójcik, T.
Wüstenfeld, J.
Zanevsky, Y.
Zeitelhack, K.
Zovinec, D.
Zumbruch, P.

Source

Physical Review Letters

Volume

Abstract

The invariant-mass spectrum of e+e- pairs produced in C12+C12 collisions at an incident energy of 2 GeV per nucleon has been measured for the first time. The measured pair production probabilities span over 5 orders of magnitude from the π0-Dalitz to the ρ/ω invariant-mass region. Dalitz decays of π0 and η account for all the yield up to 0.15GeV/c2, but for only about 50% above this mass. A comparison with model calculations shows that the excess pair yield is likely due to baryon-resonance and vector-meson decays. Transport calculations based on vacuum spectral functions fail, however, to describe the entire mass region. © 2007 The American Physical Society.