Constraining nucleon effective masses with flow and stopping observables from the S$\pi$RIT experiment

Autor: Tsang, C. Y., Kurata-Nishimura, M., Tsang, M. B., Lynch, W. G., Zhang, Y. X., Barney, J., Estee, J., Jhang, G., Wang, R., Kaneko, M., Lee, J. W., Isobe, T., Murakami, T., Ahn, D. S., Atar, L., Aumann, T., Baba, H., Boretzky, K., Brzychczyk, J., Cerizza, G., Chiga, N., Fukuda, N., Gasparic, I., Hong, B., Horvat, A., Manfredi, J., McIntosh, A. B., Morfouace, P., Nakamura, T., Nakatsuka, N., Nishimura, S., Otsu, H., Pawlowski, P., Pelczar, K., Rossi, D., Sakurai, H., Santamaria, C., Sato, H., Scheit, H., Shane, R., Shimizu, Y., Simon, H., Snoch, A., Sochocka, A., Sumikama, T., Suzuki, H., Suzuki, D., Takeda, H., Tangwancharoen, S., Törnqvist, H., Togano, Y., Xiao, Z. G., Yennello, S. J., Zhang, Y., collaboration, S$π$RIT
Rok vydání: 2023
Předmět:
Druh dokumentu: Working Paper
Popis: Properties of the nuclear equation of state (EoS) can be probed by measuring the dynamical properties of nucleus-nucleus collisions. In this study, we present the directed flow ($v_1$), elliptic flow ($v_2$) and stopping (VarXZ) measured in fixed target Sn + Sn collisions at 270 AMeV with the S$\pi$RIT Time Projection Chamber. We perform Bayesian analyses in which EoS parameters are varied simultaneously within the Improved Quantum Molecular Dynamics-Skyrme (ImQMD-Sky) transport code to obtain a multivariate correlated constraint. The varied parameters include symmetry energy, $S_0$, and slope of the symmetry energy, $L$, at saturation density, isoscalar effective mass, $m_{s}^*/m_{N}$, isovector effective mass, $m_{v}^{*}/m_{N}$ and the in-medium cross-section enhancement factor $\eta$. We find that the flow and VarXZ observables are sensitive to the splitting of proton and neutron effective masses and the in-medium cross-section. Comparisons of ImQMD-Sky predictions to the S$\pi$RIT data suggest a narrow range of preferred values for $m_{s}^*/m_{N}$, $m_{v}^{*}/m_{N}$ and $\eta$.
Databáze: arXiv