Physicists have made a significant breakthrough in understanding the creation of quark-gluon plasma (QGP), an extraordinary state of matter. By colliding gold nuclei at varying energies, they have discovered that the formation of QGP ceases at the remarkably low collision energy of 3 GeV. This finding not only contributes to the delineation of different phases of nuclear matter but also aids in identifying the conditions necessary for QGP existence and its transition from ordinary matter.
The Study
Physicists have the ability to generate a peculiar state of matter called quark-gluon plasma (QGP) by colliding gold nuclei. By systematically adjusting the collision energy, scientists have demonstrated that QGP can be formed at energies ranging from 200 billion electron volts (GeV) all the way down to 19.6 GeV. However, an intriguing observation is that QGP production seems to be “switched off” at the lowest collision energy, specifically 3 GeV. This “off” signal manifests as a change in sign, from negative to positive, in the data describing the distribution of protons produced during these collisions.
The Significance
The analysis involved comparing the collected data with numerical simulations incorporating QGP formation. If the data aligns with the predicted outcomes, it provides evidence for the creation of QGP. Consequently, the change in sign at the lowest collision energy indicates that QGP formation is halted at that energy level. These findings are invaluable for physicists in mapping the different phases of nuclear matter, understanding the temperature and density conditions necessary for QGP existence, as well as comprehending the transitions between ordinary matter and QGP.
Summary
This recent analysis employed data obtained by the Relativistic Heavy Ion Collider (RHIC) STAR detector during the initial phase of the RHIC Beam Energy Scan. Scientists from the STAR Collaboration meticulously measured the production of protons minus antiprotons on an event-by-event basis, along with various characteristics of the net-proton distribution. These observations were then compared to “first-principles” calculations based on the equations of quantum chromodynamics (QCD), which is the theory describing quark and gluon interactions. This computational approach, known as lattice QCD, simulates quark-gluon interactions within a four-dimensional space-time lattice.
The data at collision energies of 200, 62.4, 54.4, 39, 27, and 19.6 GeV were consistent with the presence of QGP. Below 19.6 GeV, the data continued to match the predicted outcomes, albeit with larger error margins indicating a higher level of uncertainty. However, at the lowest energy of 3 GeV, a remarkable shift was observed. The hierarchy among the analyzed characteristics was reversed, and correspondingly, the sign of the key relationships switched from negative to positive. This sign alteration, substantiated by the first-principles calculations, suggests that the formation of QGP is quashed at the RHIC’s minimum collision energy.
For further details on this research, refer to “When the Universe Changes Its Mind: Critical Point in Matter Transformation.”
Reference: “Beam Energy Dependence of Triton Production and Yield Ratio (Nt×Np/N2d) in Au+Au Collisions at RHIC” by M. I. Abdulhamid et al. (STAR Collaboration), 16 May 2023, Physical Review Letters.
DOI: 10.1103/PhysRevLett.130.202301
This research received funding from the Department of Energy Office of Science, Nuclear Physics program, the National Science Foundation, and several international organizations and agencies listed in the related paper. The STAR team utilized computing resources at the Scientific Data and Computing Center at Brookhaven National Laboratory, the National Energy Research Scientific Computing Center (NERSC) at Lawrence Berkeley National Laboratory, and the Open Science Grid consortium.
Table of Contents
Frequently Asked Questions (FAQs) about quark-gluon plasma
What is quark-gluon plasma (QGP)?
Quark-gluon plasma (QGP) is an exotic state of matter that can be created by colliding gold nuclei at high energies. It consists of liberated quarks and gluons, which are the fundamental building blocks of protons and neutrons.
What did physicists discover about QGP in this study?
Physicists found that the creation of QGP halts at the lowest collision energy of 3 GeV. This means that QGP formation is “turned off” at that energy level, as indicated by a change in sign from negative to positive in the data describing the distribution of protons produced during the collisions.
How does this discovery contribute to our understanding of matter?
This discovery helps in mapping out the different phases of nuclear matter and identifying the conditions under which QGP can exist. It also sheds light on the transitions between ordinary matter and the exotic state of QGP, enhancing our understanding of the fundamental properties of matter.
What methods were used in this study?
The study utilized the Relativistic Heavy Ion Collider (RHIC) STAR detector to collect data from gold nuclei collisions at various energies. The data were then compared to numerical simulations based on the equations of quantum chromodynamics (QCD), the theory describing quark and gluon interactions.
What are the implications of this research?
The research provides valuable insights into the behavior of nuclear matter and the formation of exotic states like QGP. It contributes to the broader field of high-energy physics and can potentially inform future experiments and theoretical models related to particle collisions and the nature of matter.
More about quark-gluon plasma
- “When the Universe Changes Its Mind: Critical Point in Matter Transformation” – Link
- “Beam Energy Dependence of Triton Production and Yield Ratio (Nt×Np/N2d) in Au+Au Collisions at RHIC” – Link
- Relativistic Heavy Ion Collider (RHIC) – Link
5 comments
wow, this study is so cool! physicists found that qgp stops forming at 3 gev! that’s like, super low energy! helps us understand matter better!
omg, they used the rhic star detector to collect data from gold nuclei collisions. so interesting! now we know more about qgp and its formation! awesome research!
this research provides insights into nuclear matter phases. and they used first-principles calculations based on qcd equations. fascinating stuff! can’t wait to see what other discoveries this leads to!
the study reveals the transition from ordinary matter to qgp. they measured protons and antiprotons production. qgp formation “off” at 3 gev. understanding different nuclear matter phases is mind-boggling!
qgp, an exotic state of matter, is formed when they collide gold nuclei. they found that qgp stops at 3 gev, lowest energy! amazing data analysis and simulations! expanding our knowledge of the universe!