https://doi.org/10.1140/epja/s10050-020-00269-8
Regular Article – Theoretical Physics
Deuteron and antideuteron coalescence in heavy-ion collisions: energy dependence of the formation geometry
1
School of Physics and Center of Excellence in High Energy Physics and Astrophysics, Suranaree University of Technology, Nakhon Ratchasima, 30000, Thailand
2
Institut für Theoretische Physik, Johann Wolfgang Goethe-Universität, Max-von-Laue-Str. 1, 60438, Frankfurt am Main, Germany
3
Helmholtz Research Academy Hesse for FAIR, Campus Frankfurt, Max-von-Laue-Str. 12, 60438, Frankfurt am Main, Germany
4
University of Sarajevo, Obala Kulina bana 7/II, 71000, Sarajevo, Bosnia and Herzegovina
* e-mail: apiwitkitti@g.sut.ac.th
Received:
2
June
2020
Accepted:
5
October
2020
Published online:
27
October
2020
We investigate the collision energy dependence of deuteron and antideuteron emission in the RHIC-BES low- to mid-energy range $$\sqrt{s_{NN}}$$ = 4.6–200 GeV where the formation rate of antinuclei compared to nuclei is strongly suppressed. In the coalescence picture, this can be understood as bulk emission for nuclei in contrast to surface emission for antinuclei. By comparison with experimental data on the coalescence parameter $$B_2$$, we are able to extract the respective source geometries. This interpretation is further supported by results from the UrQMD transport model, and establishes the following picture: At low energies, nucleons freeze out over the total fireball volume, while antinucleons are annihilated inside the nucleon-rich fireball and can only freeze out on its surface. Towards higher energies, this annihilation effect becomes less significant because of the enhanced meson production in the reaction. Thus, the nucleon and antinucleon freeze-out distributions become similar with increasing energy.
© Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature, 2020
