A phenomenological approach to direct K^* production and hadronic medium effects in nucleus-nucleus collisions at high baryon density

@misc{li2026phenomenological,
  title = {{A phenomenological approach to direct $\rmK^*$ production and hadronic medium effects in nucleus-nucleus collisions at high baryon density}},
  author = {Hongcan Li and Yun Liu and Guangyu Zheng and Yaping Wang and Guannan Xie and Gao-chan Yong},
  howpublished = {arXiv},
  year = {2026},
  month = sep,
  doi = {10.48550/arxiv.2609.07442},
  eprint = {2609.07442},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2609.07442},
  note = {CC BY 4.0},
}

TY  - UNPB
TI  - A phenomenological approach to direct K^* production and hadronic medium effects in nucleus-nucleus collisions at high baryon density
AU  - Hongcan Li
AU  - Yun Liu
AU  - Guangyu Zheng
AU  - Yaping Wang
AU  - Guannan Xie
AU  - Gao-chan Yong
PY  - 2026
DA  - 2026/09/07
PB  - arXiv
DO  - 10.48550/arxiv.2609.07442
UR  - https://arxiv.org/abs/2609.07442
AB  - Short-lived hadron resonances serve as sensitive probes of the late-stage hadronic medium in heavy-ion collisions. Using the AMPT-HC model, we study K^*(892) production and its hadronic medium effects in Au+Au collisions at √(s_NN) = 3 GeV, a region of high baryon density. We introduce a phenomenological direct-production mechanism for K^* by replacing a fraction of the final-state kaons produced in the NN → NYK and MN → YK channels with K^* resonances, with the substitution fraction controlled by a parameter α while conserving four-momentum. The direct K^* is produced early, at about 6 fm/c, with little centrality dependence, whereas resonance fusion via K+π→K^* occurs later, with the mean production time increasing from about 8 to 10 fm/c toward central collisions. Consequently, direct K^* mesons suffer stronger daughter rescattering, leading to a pronounced decrease in reconstruction efficiency toward central collisions, while the K^* survival rate remains close to unity. Elastic scattering of the daughters also shifts the invariant mass away from the resonance peak, contributing to the background-like component. The K^*/K centrality dependence reflects the competition between direct production and resonance fusion and is sensitive to α. At 3 GeV, a moderate direct-production contribution may result in an increasing K^*/K ratio toward central collisions, providing a testable prediction for future measurements.
ER  -