A heavy bottom (b) quark and anti-bottom quark bound together form a meson called bottomonium at low temperature. Theorists have carried out computations to anticipate the temperature level at which bottomonium mesons will melt. Bottomonium mesons are particles made of one of the 6 types of quark: a heavy bottom quark bound to its antimatter partner, an antibottom quark. To figure out the temperature at which bottomonium states melt in the quark-gluon plasma, researchers at Brookhaven Lab, Homi Bhabha National Institute in India, and Humboldt-University in Berlin determined meson correlation functions. These functions are a measure of the interaction in between the quark and antiquark making up bottomonium.
Summary
To determine the temperature level at which bottomonium mentions melt in the quark-gluon plasma, researchers at Brookhaven Lab, Homi Bhabha National Institute in India, and Humboldt-University in Berlin calculated meson connection functions. These functions are a procedure of the interaction between the quark and antiquark making up bottomonium. The researchers utilized effective supercomputers and a technique called lattice quantum chromodynamics (QCD) to design the interactions in one of the spatial measurements. They found that this connection function decays exponentially in the spatial separation. The rate of this exponential decay is related to the screening mass. The value of the screening mass is related to the binding energy in between the bottom (b) quark and the anti-b quark. The temperature dependence of this screening mass is very different depending on whether the heavy quark and anti-quark are bound inside a meson or move separately in QGP as an unbound pair (such as if the meson has melted).
The smallest bottomonium (one five times smaller than a proton) only melts at this temperature level. This may discuss the substantial bottomonium yield at both RHIC and LHC.
Referral: “Bottomonium melting from screening correlators at high temperature level” by Peter Petreczky, Sayantan Sharma and Johannes Heinrich Weber, 24 September 2021, Physical Review D.DOI: 10.1103/ PhysRevD.104.054511.
This research study was funded by the Department of Energy Office of Science, Nuclear Physics program.
By U.S. Department of Energy
June 11, 2023
A heavy bottom (b) quark and anti-bottom quark bound together form a meson called bottomonium at low temperature. Bottomoniums may melt at greater temperature levels. Credit: Brookhaven National Laboratory
Researchers calculations indicate that bottomonium mesons, formed by a bottom quark and its antimatter counterpart, require temperature levels above 5.8 trillion degrees Celsius to melt. This provides insight into why fewer bottomonium particles are observed in high-energy accidents at the Large Hadron Collider compared to the Relativistic Heavy Ion Collider, and provides new opportunities for studying quark-gluon plasma properties.
The Science
Theorists have performed computations to predict the temperature level at which bottomonium mesons will melt. Bottomonium mesons are particles made of one of the six types of quark: a heavy bottom quark bound to its antimatter partner, an antibottom quark.
The Impact
The findings offer a possible explanation for why scientists observe fewer bottomonium particles in heavy ion collisions at the Large Hadron Collider (LHC) than at the Relativistic Heavy Ion Collider (RHIC). The LHC particle accelerator is at CERN in Europe, and the RHIC is a Department of Energy user center at Brookhaven National Laboratory. Crashes in between atomic nuclei at both facilities can melt protons and neutrons to release the quarks and gluons within. However, the resulting quark-gluon plasma ( QGP) may not be adequately hot to completely melt bottomonium. These accidents can still produce bottomonium particles, albeit at a lower rate. This theoretical assistance might advance using bottomonium melting as a tool for studying the homes of QGP.
