https://doi.org/10.1140/epja/s10050-020-00264-z
Regular Article – Theoretical Physics
Azimuthal anisotropy and multiplicities of hard photons and free nucleons in intermediate-energy heavy-ion collisions
1
Key Laboratory of Nuclear Physics and Ion-beam Application (MOE), Institute of Modern Physics, Fudan University, Shanghai, 200433, China
2
Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, 201800, China
3
University of Chinese Academy of Sciences, Beijing, 100049, China
4
Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai, 201210, China
5
Institute of Particle and Nuclear Physics, Henan Normal University, Xinxiang, 453007, China
* e-mail: mayugang@fudan.edu.cn
Received:
10
June
2020
Accepted:
27
September
2020
Published online:
6
October
2020
Anisotropic flow can offer significant information of evolution dynamics in heavy-ion collisions. A systematic study of the directed flow $$v_1$$ and elliptic flow $$v_2$$ of hard photons and free nucleons is performed for $$^{40}$$Ca + $$^{40}$$Ca collisions in a framework of isospin-dependent quantum molecular dynamics (IQMD) model. The study firstly reveals that thermal photons emitted in intermediate-energy heavy-ion collisions have the behaviors of directed and elliptic flows. The interesting phenomena of incident energy dependence of $$v_1$$ and $$v_2$$ for thermal photons in central collisions also confirmed that it can be regarded as a good probe of evolution dynamics. Moreover, the multiplicities of hard photons and free nucleons and their correlation are also investigated. We find that direct photon emission is positively related to free nucleons emission, however, there exists an anti-correlation for thermal photons with free nucleons.
© Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature, 2020
