In the realm of high-energy physics, a team of researchers from the Institute of Physics, Bhubaneswar, India, has delved into the intricate dynamics of particle collisions. The team, comprising S. Biswal, M. A. Bhat, A. Nayak, S. I. Sahoo, D. Dutta, D. K. Mishra, and P. K. Sahu, has published their findings in the journal Physical Review C.
The researchers have conducted a comprehensive study on the initial energy density in xenon-xenon (Xe-Xe) collisions at an energy level of 5.44 TeV per nucleon pair. This energy density, known as the Bjorken initial energy density, was estimated using data on charged-particle multiplicity and a generalized transverse overlap geometry that is applicable beyond the most central collisions. The study also examined the dependence of the extracted energy density by adopting both a constant formation time and a centrality-dependent formation time derived from lead-lead (Pb-Pb) collisions at an energy level of 5.02 TeV per nucleon pair. Corresponding Bjorken energy density estimates for Pb-Pb collisions were also presented for comparison.
Taking the Bjorken energy density and formation time as initial conditions, the researchers studied the subsequent longitudinal evolution of the quark-gluon plasma (QGP) formed in these collisions. Both ideal and first-order viscous boost-invariant hydrodynamics were employed to assess the influence of dissipation. The findings revealed that viscous effects slow the longitudinal expansion and lead to entropy production dominated by early-time dynamics. The lifetime of the QGP was observed to increase with centrality and is substantially enhanced by viscous effects. These effects were found to be highly sensitive to the choice of formation time, particularly in peripheral collisions.
A comparative analysis of Xe-Xe and Pb-Pb collisions demonstrated that the longitudinal evolution is primarily controlled by the initial energy density scale set by the Bjorken prescription. Consequently, when this scale is comparable, both systems exhibit nearly identical evolution patterns, while appreciable distinctions emerge in peripheral collisions due to system-size and geometric effects.
The practical applications of this research for the energy sector are not immediately apparent, as this study is more aligned with fundamental physics research. However, understanding the behavior of matter under extreme conditions, such as those created in high-energy particle collisions, can have broader implications for various fields, including energy research. For instance, insights gained from studying the properties of QGP could potentially inform the development of new materials or technologies that can withstand or operate in extreme environments. Moreover, the advanced computational and analytical techniques used in such studies can also be applied to complex problems in energy systems.
Source: Physical Review C
This article is based on research available at arXiv.