Probing the Mechanisms of Baryon Number Transport from RHIC to the EIC

A central open question in Quantum Chromodynamics (QCD) concerns the true carrier of baryon number within the nucleon. While the conventional quark model attributes this quantum number to the three valence quarks, non-perturbative QCD proposes an intriguing alternative: the baryon junction, a Y-shaped gluonic configuration that could play a pivotal role in baryon number transport. In this talk, we present a phenomenological study aimed at unraveling the mechanisms behind baryon transport, with a two-fold focus: (i) interpreting recent STAR experimental results [1] and (ii) outlining critical future measurements at RHIC and the upcoming Electron-Ion Collider (EIC) [2]. Leveraging the PYTHIA-8 event generator for heavy-ion collisions, we show that models incorporating advanced color reconnection and color flow, key features that emulate baryon junction dynamics, are necessary to account for the observed enhancement of baryon-to-charge transport at mid-rapidity reported by STAR. Looking ahead, we propose a targeted set of measurements for the EIC using the BeAGLE model framework, designed to unambiguously probe baryon number transport mechanisms in a new kinematic regime. By integrating insights from current RHIC data with these forward-looking EIC studies, we outline a comprehensive strategy to address the longstanding puzzle of baryon number transport in high-energy nuclear interactions.

[1] Niseem Magdy, Abhay Deshpande, Roy Lacey, Wenliang Li, Prithwish Tribedy, Zhangbu Xu, Search for baryon junctions in e+A collisions at the electron ion collider, Eur. Phys. J. C 84 (2024) 12, 1326

[2] Niseem Magdy, Prithwish Tribedy, Chun Yuen Tsang, Zhangbu Xu, Understanding the Baryon Stopping at the Relativistic Heavy Ion Collider, e-Print: 2504.09826