An Improved Core-Corona Model for Λ and Λ Polarization in Relativistic Heavy-Ion Collisions

Particles

article

Alejandro Ayala¹  Isabel Dominguez⁴  Ivonne Maldonado⁵  Maria Elena Tejeda-Yeomans⁶ 

[1] Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México;Centre for Theoretical and Mathematical Physics, Department of Physics, University of Cape Town;Departamento de Física, Universidade Federal de Santa Maria;Facultad de Ciencias Físico-Matemáticas, Universidad Autónoma de Sinaloa, Avenida de las Américas y Boulevard Universitarios, Ciudad Universitaria;Joint Institute for Nuclear Research;Facultad de Ciencias—CUICBAS, Universidad de Colima

关键词: hyperon;    global polarization;    core-corona;    heavy-ion collisions;    spin;   

DOI  :  10.3390/particles6010022

学科分类：社会科学、人文和艺术（综合）

来源: mdpi

【 摘 要 】

Due to its sensitivity to the dynamics of strongly interacting matter subject to extreme conditions, hyperon global polarization has become an important observable to study the system created in relativistic heavy-ion collisions. Recently, the STAR and HADES collaborations have measured the global polarization of bothΛand Λ ¯ produced in semi-central collisions in a wide range of collision energies. The polarization excitation functions show an increasing trend as the collision energy decreases, with the increase being more pronounced for the Λ ¯. In this work, we make a summary of a core-corona model that we have developed to quantify the global polarization contributions fromΛand Λ ¯ created in different regions of the fireball. The core-corona model assumes thatΛ s and Λ ¯s are produced in both regions, the high-density core and the lower density corona, with different relative abundances which modulate the polarization excitation function. We have shown that the model works well for the description of experimental results. The global polarization excitation functions computed with the model show a peak at different collision energies in the region sN N≤ 10 GeV. Finally, we discuss and report on the model global polarization predictions for BES-II, NICA and CBM at FAIR and HADES energies.

【 授权许可】

CC BY