Improved opacity expansion at NNLO for medium induced gluon radiation
Abstract When an energetic parton propagates in a hot and dense QCD medium it loses energy by elastic scatterings or by medium-induced gluon radiation. The gluon radiation spectrum is suppressed at high frequency due to the LPM effect and encompasses two regimes that are known analytically: at high...
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doaj-3cc1479ae370403fb1f5cbb39c81dd2b2020-11-25T03:58:15ZengSpringerOpenJournal of High Energy Physics1029-84792020-10-0120201012710.1007/JHEP10(2020)176Improved opacity expansion at NNLO for medium induced gluon radiationJoão Barata0Yacine Mehtar-Tani1Physics Department, Brookhaven National LaboratoryPhysics Department, Brookhaven National LaboratoryAbstract When an energetic parton propagates in a hot and dense QCD medium it loses energy by elastic scatterings or by medium-induced gluon radiation. The gluon radiation spectrum is suppressed at high frequency due to the LPM effect and encompasses two regimes that are known analytically: at high frequencies ω > ω c = q ̂ L 2 $$ \omega >{\omega}_c=\hat{q}{L}^2 $$ , where q ̂ $$ \hat{q} $$ is the jet quenching transport coefficient and L the length of the medium, the spectrum is dominated by a single hard scattering, whereas the regime ω < ω c is dominated by multiple low momentum transfers. In this paper, we extend a recent approach (dubbed the Improved Opacity Expansion (IOE)), which allows an analytic (and systematic) treatment beyond the multiple soft scattering approximation, matching this result with the single hard emission spectrum. We calculate in particular the NNLO correction analytically and numerically and show that it is strongly suppressed compared to the NLO indicating a fast convergence of the IOE scheme and thus, we conclude that it is sufficient to truncate the series at NLO. We also propose a prescription to compare the GW and the HTL potentials and relate their parameters for future phenomenological works.http://link.springer.com/article/10.1007/JHEP10(2020)176Heavy Ion PhenomenologyJets |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
João Barata Yacine Mehtar-Tani |
spellingShingle |
João Barata Yacine Mehtar-Tani Improved opacity expansion at NNLO for medium induced gluon radiation Journal of High Energy Physics Heavy Ion Phenomenology Jets |
author_facet |
João Barata Yacine Mehtar-Tani |
author_sort |
João Barata |
title |
Improved opacity expansion at NNLO for medium induced gluon radiation |
title_short |
Improved opacity expansion at NNLO for medium induced gluon radiation |
title_full |
Improved opacity expansion at NNLO for medium induced gluon radiation |
title_fullStr |
Improved opacity expansion at NNLO for medium induced gluon radiation |
title_full_unstemmed |
Improved opacity expansion at NNLO for medium induced gluon radiation |
title_sort |
improved opacity expansion at nnlo for medium induced gluon radiation |
publisher |
SpringerOpen |
series |
Journal of High Energy Physics |
issn |
1029-8479 |
publishDate |
2020-10-01 |
description |
Abstract When an energetic parton propagates in a hot and dense QCD medium it loses energy by elastic scatterings or by medium-induced gluon radiation. The gluon radiation spectrum is suppressed at high frequency due to the LPM effect and encompasses two regimes that are known analytically: at high frequencies ω > ω c = q ̂ L 2 $$ \omega >{\omega}_c=\hat{q}{L}^2 $$ , where q ̂ $$ \hat{q} $$ is the jet quenching transport coefficient and L the length of the medium, the spectrum is dominated by a single hard scattering, whereas the regime ω < ω c is dominated by multiple low momentum transfers. In this paper, we extend a recent approach (dubbed the Improved Opacity Expansion (IOE)), which allows an analytic (and systematic) treatment beyond the multiple soft scattering approximation, matching this result with the single hard emission spectrum. We calculate in particular the NNLO correction analytically and numerically and show that it is strongly suppressed compared to the NLO indicating a fast convergence of the IOE scheme and thus, we conclude that it is sufficient to truncate the series at NLO. We also propose a prescription to compare the GW and the HTL potentials and relate their parameters for future phenomenological works. |
topic |
Heavy Ion Phenomenology Jets |
url |
http://link.springer.com/article/10.1007/JHEP10(2020)176 |
work_keys_str_mv |
AT joaobarata improvedopacityexpansionatnnloformediuminducedgluonradiation AT yacinemehtartani improvedopacityexpansionatnnloformediuminducedgluonradiation |
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1724458332114124800 |