Measurement of kaon directed flow in Au+Au collisions in the high baryon density region

Authors

• B. E. Aboona, Texas AandM University
• J. Adam, Czech Technical University in Prague
• G. Agakishiev, Joint Institute for Nuclear Research, Dubna
• I. Aggarwal, Panjab University
• M. M. Aggarwal, Panjab University
• Z. Ahammed, Variable Energy Cyclotron Centre
• A. Aitbayev, Joint Institute for Nuclear Research, Dubna
• I. Alekseev, Alikhanov Institute for Theoretical and Experimental Physics
• E. Alpatov, Moscow Engineering Physics Institute
• A. K. Alshammri, Kent State University
• A. Aparin, Joint Institute for Nuclear Research, Dubna
• S. Aslam, Fudan University
• J. Atchison, Abilene Christian University
• G. S. Averichev, Joint Institute for Nuclear Research, Dubna
• V. Bairathi, Universidad de Tarapaca
• X. Bao, Shandong University
• P. Barik, Indian Institute of Science Education and Research (IISER)
• K. Barish, University of California Riverside
• S. Behera, Indian Institute of Science Education and Research (IISER) Tirupati
• P. Bhagat, University of Jammu
• A. Bhasin, University of Jammu
• S. Bhatta, Stony Brook University
• I. G. Bordyuzhin, Alikhanov Institute for Theoretical and Experimental Physics
• J. D. Brandenburg, Ohio State University
• A. V. Brandin, Moscow Engineering Physics Institute
• C. Broodo, University of Houston
• X. Z. Cai, Chinese Academy of Sciences
• H. Caines, Yale University
• M. Calderón de la Barca Sánchez, University of California Davis
• D. Cebra, University of California Davis
• J. Ceska, Czech Technical University in Prague

Abstract

Rapidity-odd directed flow v ₁ measurements are presented for K ^± and K_S⁰ in Au + Au collisions for s_NN from 3.0 to 3.9 GeV with the STAR experiment. For comparison, v ₁ of π ^± , protons, and Λ from the same collisions are also discussed. The mid-rapidity v ₁ slope dv₁/dy|_y=0 for protons and Λ is positive in these collisions. On the other hand, v ₁ slope of kaons exhibits a strong p_T dependence: negative at p_T< 0.6 GeV/ c and positive at higher p_T. A similar p_T dependence is also evident for the v ₁ slope of charged pions. Compared to the spectator-removed calculations in Au+Au collisions at s_NN= 3.0–3.9 GeV, the JAM model demonstrates a pronounced shift of the v ₁ slopes of mesons towards the negative direction. It suggests that the shadowing effect of the spectators plays an important role in the observed kaon anti-flow at low p_T in the high baryon density region of non-central collisions.

Document Type

Article

Publication Date

4-1-2026

Notes/Citation Information

Publisher Copyright: © 2026 The Authors.

Digital Object Identifier (DOI)

10.1016/j.physletb.2026.140353

Archival?

Archival

Repository Citation

Aboona, B. E.; Adam, J.; Agakishiev, G.; Aggarwal, I.; Aggarwal, M. M.; Ahammed, Z.; Aitbayev, A.; Alekseev, I.; Alpatov, E.; Alshammri, A. K.; Aparin, A.; Aslam, S.; Atchison, J.; Averichev, G. S.; Bairathi, V.; Bao, X.; Barik, P.; Barish, K.; Behera, S.; Bhagat, P.; Bhasin, A.; Bhatta, S.; Bordyuzhin, I. G.; Brandenburg, J. D.; Brandin, A. V.; Broodo, C.; Cai, X. Z.; Caines, H.; Calderón de la Barca Sánchez, M.; Cebra, D.; and Ceska, J., "Measurement of kaon directed flow in Au+Au collisions in the high baryon density region" (2026). Physics and Astronomy Faculty Publications. 783.
https://uknowledge.uky.edu/physastron_facpub/783