利用Sn+Sn系统产π介子研究对称能
核实验
2020-12-23 v1 核理论
摘要
在过去二十年中，重离子碰撞高密度区产生的π介子被预测对核状态方程中的对称能项在高密度下敏感，这一性质是我们理解中子星的关键。在一项旨在研究对称能的新实验中，使用SπRIT时间投影室以高精度测量了中心Sn+Sn、Sn+Sn和Sn+Sn碰撞在下的带负电和带正电π介子的多重数。虽然单个π介子多重数的不确定度测量为4%，但带电π介子多重数比值的不确定度测量为2%。我们将这些数据与七个主要输运模型的预测进行比较。这些计算定性地再现了多重数及其比值对碰撞系统中总中子与质子数依赖关系。然而，来自不同代码的输运模型的预测差异过大，无法从数据中可靠地提取对称能的约束条件。这一发现可能解释先前从Au+Au系统的π介子数据获得的关于对称能约束的矛盾结论。这些新结果呼吁更好地理解输运代码之间的差异，以及寻找对对称能密度依赖性更敏感的新观测量。
引用
@article{arxiv.2012.06976,
title = {Symmetry energy investigation with pion production from Sn+Sn systems},
author = {G. Jhang and J. Estee and J. Barney and G. Cerizza and M. Kaneko and J. W. Lee and W. G. Lynch and T. Isobe and M. Kurata-Nishimura and T. Murakami and C. Y . Tsang and M. B. Tsang and R. Wang and D. S. Ahn and L. Atar and T. Aumann and H. Baba and K. Boretzky and J. Brzychczyk and N. Chiga and N. Fukuda and I. Gasparic and B. Hong and A. Horvat and K. Ieki and N. Inabe and Y. J. Kim and T. Kobayashi and Y. Kondo and P. Lasko and H. S. Lee and Y. Leifels and J. Łukasik and J. Manfredi and A. B. McIntosh and P. Morfouace and T. Nakamura and N. Nakatsuka and S. Nishimura and R. Olsen and H. Otsu and P. Pawłowski and K. Pelczar and D. Rossi and H. Sakurai and C. Santamaria and H. Sato and H. Scheit and R. Shane and Y. Shimizu and H. Simon and A. Snoch and A. Sochocka and Z. Sosin and T. Sumikama and H. Suzuki and D. Suzuki and H. Takeda and S. Tangwancharoen and H. Toernqvist and Y. Togano and Z. G. Xiao and S. J. Yennello and J. Yurkon and Y. Zhang and Maria Colonna and Dan Cozma and Paweł Danielewicz and Hannah Elfner and Natsumi Ikeno and Che Ming Ko and Justin Mohs and Dmytro Oliinychenko and Akira Ono and Jun Su and Yong Jia Wang and Hermann Wolter and Jun Xu and Ying-Xun Zhang and Zhen Zhang},
journal= {arXiv preprint arXiv:2012.06976},
year = {2020}
}
备注
8 pages, 4 figures, 1 table (accepted for publication in PLB)