Transport Model Comparison Studies of Intermediate-Energy Heavy-Ion Collisions

• Main Authors: Wolter, Hermann, Colonna, Maria, Cozma, Dan, Danielewicz, Pawel, Ko, Che Ming, Kumar, Rohit, Ono, Akira, Tsang, ManYee Betty, Xu, Jun, Zhang, Ying-Xun, Bratkovskaya, Elena, Feng, Zhao-Qing, Gaitanos, Theodoros, Fèvre, Arnaud Le, Ikeno, Natsumi, Kim, Youngman, Mallik, Swagata, Napolitani, Paolo, Oliinychenko, Dmytro, Ogawa, Tatsuhiko, Papa, Massimo, Su, Jun, Wang, Rui, Wang, Yong-Jia, Weil, Janus, Zhang, Feng-Shou, Zhang, Guo-Qiang, Zhang, Zhen, Aichelin, Joerg, Cassing, Wolfgang, Chen, Lie-Wen, Cheng, Hui-Gan, Elfner, Hannah, Gallmeister, K, Hartnack, Christoph, Hashimoto, Shintaro, Jeon, Sangyong, Kim, Kyungil, Kim, Myungkuk, Li, Bao-An, Lee, Chang-Hwan, Li, Qing-Feng, Li, Zhu-Xia, Mosel, Ulrich, Nara, Yasushi, Niita, Koji, Ohnishi, Akira, Sato, Tatsuhiko, Song, Taesoo, Sorensen, Agnieszka, Wang, Ning, Xie, Wen-Jie
• Format: Journal Article
• Language: English
• Published: 04-05-2022
• Subjects: Physics - Nuclear Experiment; Physics - Nuclear Theory
• DOI: 10.48550/arxiv.2202.06672

Prog. Part. Nucl. Phys. 125 (2022) 103962 Transport models are the main method to obtain physics information from low
to relativistic-energy heavy-ion collisions. The Transport Model Evaluation
Project (TMEP) has been pursued to test the robustness of transport model
predictions in reaching consistent conclusions from the same type of physical
model. Calculations under controlled conditions of physical input and set-up
were performed with various participating codes. These included both
calculations of nuclear matter in a box with periodic boundary conditions, and
more realistic calculations of heavy-ion collisions. In this intermediate
review, we summarize and discuss the present status of the project. We also
provide condensed descriptions of the 26 participating codes, which contributed
to some part of the project. These include the major codes in use today. We
review the main results of the studies completed so far. They show, that in box
calculations the differences between the codes can be well understood and a
convergence of the results can be reached. These studies also highlight the
systematic differences between the two families of transport codes, known as
BUU and QMD type codes. However, when the codes were compared in full heavy-ion
collisions using different physical models, as recently for pion production,
they still yielded substantially different results. This calls for further
comparisons of heavy-ion collisions with controlled models and of box
comparisons of important ingredients, like momentum-dependent fields, which are
currently underway. We often indicate improved strategies in performing
transport simulations and thus provide guidance to code developers. Results of
transport simulations of heavy-ion collisions from a given code will have more
significance if the code can be validated against benchmark calculations such
as the ones summarized in this review.