Directed Flow of Protons and Deuterons in Xe+Cs(I) Collisions: Preliminary BM@N Data and THESEUS Modeling

Abstract

Preliminary BM@N results on the directed flow ($v_1$) of protons and deuterons in Xe+Cs(I) collisions at 3.8$A$ GeV are presented for the 10-40% centrality interval. The measured rapidity dependence of $v_1$ is compared with calculations from the THESEUS event generator, where deuterons are produced thermodynamically on an equal basis with hadrons using a late freeze-out scenario. While THESEUS well describes the proton $v_1$ data, it shows a slight but systematic overestimation of the deuteron flow at low and intermediate rapidities. This comparison tests both the collective dynamics of baryon-rich matter and the thermodynamic mechanism of light-nucleus formation at Nuclotron energies.

Comments: 4 pages, 1 figure, MMCP 2026 proceedings