Heavy Quark Diffusion from 2+1 Flavor Lattice QCD with 320 MeV Pion Mass

Area of Science:

• Nuclear Physics
• High Energy Physics
• Quantum Chromodynamics

Background:

• Understanding the properties of quark-gluon plasma (QGP) is crucial for comprehending the early universe.
• Heavy quarks are essential probes for studying the QGP due to their mass.
• Lattice QCD provides a non-perturbative framework to study the properties of strongly interacting matter.

Purpose of the Study:

• To compute the heavy flavor diffusion coefficient using lattice QCD with light dynamical quarks.
• To compare these results with previous theoretical and phenomenological estimates.
• To investigate the implications for heavy quark dynamics in the QGP.

Main Methods:

• Utilizing lattice quantum chromodynamics (QCD) simulations.
• Employing light dynamical quarks with a pion mass of approximately 320 MeV.
• Performing calculations for temperatures in the range of 195 MeV < T < 352 MeV.

Main Results:

• The heavy quark spatial diffusion coefficient was calculated for the first time with light dynamical quarks.
• Results indicate a significantly smaller diffusion coefficient compared to quenched lattice QCD and phenomenological models.
• The calculated diffusion coefficient is substantially lower than prior estimates.

Conclusions:

• The findings suggest that heavy quarks hydrodynamize very rapidly in the QGP.
• This implies a stronger interaction between heavy quarks and the QGP medium than previously thought.
• The study provides crucial insights into the transport properties of the QGP.