STAR results on strangeness and electric charge-dependent splitting of rapidity-odd directed flow

Rapidity-odd directed flow ([Formula: see text]) of multi-strange baryons ([Formula: see text] and [Formula: see text]) at mid-rapidity is reported for Au+Au collisions as recorded by the STAR detector at the Relativistic Heavy Ion Collider (RHIC). We focus on particle species where all constituent quarks are produced, such as [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text], and demonstrate using a novel analysis method that the coalescence sum rule holds in a common kinematic region for hadron combinations with identical quark content. We examine the coalescence sum rule as a function of rapidity for nonidentical quark content having the same quark-level mass but different strangeness ([Formula: see text]) and electric charge ([Formula: see text]). The difference in the directed flow of different quark and anti-quark combinations, e.g., [Formula: see text], is a measure of coalescence sum rule violation, and we call it directed flow splitting ([Formula: see text]). We measure [Formula: see text] and [Formula: see text] dependence of the [Formula: see text] slope ([Formula: see text]) between produced quarks and anti-quarks in Au+Au collisions at [Formula: see text][Formula: see text]GeV and 200[Formula: see text]GeV. Measurements have been compared with A Multi-Phase Transport (AMPT) and Parton-Hadron String Dynamics (PHSD) models with electromagnetic field calculations.