Simulating jets and heavy quarks in the glasma using the colored particle-in-cell method

Abstract

We explore the impact of strong classical color fields, which occur in the earliest stages of heavy-ion collisions and are known as the glasma, on the classical transport of hard probes, namely heavy quarks and jets. To achieve this, we simulate SU(3) color fields using classical real-time lattice gauge theory and couple them to an ensemble of test particles whose dynamics are described by Wong’s equations. We provide an overview of how classical color algebras are constructed and introduce a method to generate random classical SU(3) color charges. We extensively test our numerical particle solver in the limits of infinitely massive heavy quarks and ultrarelativistic lightlike jets and obtain excellent quantitative agreement with previous studies. Going towards realistic masses and initial momenta, we extract longitudinal and transverse momentum broadening for heavy quarks and jets. The resulting accumulated momenta and the anisotropy of these dynamical hard probes exhibit deviations from limiting scenarios, showing that the full dynamics have a significant effect.