Estimating the Color Lifetime of Energetic Quarks

Abstract

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$0.011 GeV${}^2$/fm. With a three-parameter model we obtain satisfactory fits to the data with a goodness-of-fit parameter ${\chi }^2$/dof of 1.1 or less. In a secondary fit of the results from that model we independently find a value for the Lund String Model string tension of 1.00$\pm$0.05 GeV/fm. We evaluated the sensitivity for extracting quark energy loss and effective in-medium hadronic cross sections using four-parameter variants of the model, finding large uncertainties in both cases. Our results suggest that hadronic interaction of forming hadrons in the nuclear medium is the primary dynamical cause of meson attenuation in the HERMES data, with quark energy loss playing a more minor role.

13 pages in total, 5 figures, 1 table, supplementary material starting page 11, Physics Letters B, Volume 816, 2021, 136171

References in corpus (17)

• PYTHIA 6.4 Physics and Manual
• Global analysis of fragmentation functions for pions and kaons and their uncertainties
• The theory and phenomenology of perturbative QCD based jet quenching
• Global Analysis of Fragmentation Functions for Protons and Charged Hadrons
• Parton-to-Pion Fragmentation Reloaded
• Short Range Correlations and the EMC Effect
• Isoscalar $\pi \pi$ scattering and the $\sigma$ meson resonance from QCD
• Towards a resolution of the proton form factor problem: new electron and positron scattering data
• ${}^6$He nucleus in halo effective field theory
• Time Dependent Hadronization via HERMES and EMC Data Consistency
• Nucleon structure in a light-front quark model consistent with quark counting rules and data
• The energy and scale dependence of $\hat{q}$ and the JET puzzle
• Nuclear physics in soft-wall AdS/QCD: Deuteron electromagnetic form factors
• A global extraction of the jet transport coefficient in cold nuclear matter
• The in-medium scale evolution in jet modification
• Spacetime development of in-medium hadronization: Scenario for leading hadrons
• Average formation length in string model

Cited by in corpus (4)

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• Strong Interaction Physics at the Luminosity Frontier with 22 GeV Electrons at Jefferson Lab
• Observation of azimuth-dependent suppression of hadron pairs in electron scattering off nuclei