Estimating the Color Lifetime of Energetic Quarks

Understand

Using a simple geometric framework with a realistic nuclear density distribution, we fit published HERMES data to determine fundamental properties of hadronization using the nuclear medium as a spatial analyzer.

• Our approach uses a fit to the transverse momentum broadening observable and the hadronic multiplicity ratio; the simultaneous fit to two different observables strongly constrains the outcome.
• Using the known sizes of the target nuclei, we extract the color lifetime, finding a z$\mathrm{_h}$-dependent range of values from 2 to 8 fm/c for these data.
• We also extract estimates for the $\hat{q}$ transport coefficient characterizing the strength of the interaction between the quark and the cold nuclear medium, finding an average value of 0.035$\pm$0.011 GeV$\mathrm{^2}$/fm.