In the realm of high-energy physics, a team of researchers from the University of Catania, Italy, has been delving into the intricate dynamics of proton-nucleus collisions. Gabriele Parisi, Fabrizio Murgana, Vincenzo Greco, and Marco Ruggieri have been investigating the behavior of charm quarks in the early stages of these collisions, with their findings recently published in the journal Physical Review C.
The researchers focused on the initial, pre-equilibrium stage of high-energy proton-nucleus collisions, modeling it within the Color Glass Condensate framework as an evolving glasma. This stage was initialized through the McLerran–Venugopalan model, with subnucleonic fluctuations implemented as constituent-quark hotspots for both the proton and the nuclear participants. Charm quarks were then propagated in the evolving non-Abelian background by solving the relativistic Wong equations for their coordinates, momenta, and color charges.
Firstly, the team computed the nuclear modification factor of charm quarks, observing a slight migration towards higher transverse momentum (pT) states, consistent with previous research. The study then turned to the azimuthal anisotropies acquired through the interaction with glasma fields. The researchers found that glasma-induced momentum anisotropies are efficiently transmitted to heavy quarks within approximately 0.4 femtoseconds per centimeter (fm/c), leading to a significant charm-quark elliptic flow (v2). The magnitude of this flow increases with the strength of the initial fields and with the number of nuclear participants.
Remarkably, the study demonstrated that the early-stage contribution alone can account for a significant fraction of the experimentally observed J/ψ elliptic flow in proton-lead (p-Pb) collisions. This indicates that pre-hydrodynamic dynamics can play a non-negligible role in the final-state heavy-flavor collectivity, especially in small systems.
While this research is primarily of academic interest, understanding the behavior of charm quarks and their interactions in high-energy collisions can have implications for the energy industry. For instance, the insights gained from these studies can contribute to the development of more accurate models for particle interactions, which can be crucial for advancing technologies like particle accelerators and other high-energy systems. Moreover, the understanding of quark-gluon plasma and its properties can potentially lead to innovations in energy production and management, although these applications are still in the realm of theoretical exploration.
In conclusion, the work of Parisi, Murgana, Greco, and Ruggieri sheds light on the complex dynamics of charm quarks in the early stages of proton-nucleus collisions, highlighting the importance of pre-hydrodynamic dynamics in heavy-flavor collectivity. Their findings, published in Physical Review C, contribute to the broader understanding of high-energy physics and its potential applications in the energy sector.
This article is based on research available at arXiv.