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arXiv · 1009.2965

Antiangular Ordering of Gluon Radiation in QCD Media

Yacine Mehtar-Tani·Carlos A. Salgado·Konrad Tywoniuk
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Abstract

We investigate angular and energy distributions of medium-induced gluon emission off a quark-antiquark antenna in the framework of perturbative QCD as an attempt toward understanding, from first principles, jet evolution inside the quark-gluon plasma. In-medium color coherence between emitters, neglected in all previous calculations, leads to a novel mechanism of soft-gluon radiation. The structure of the corresponding spectrum, in contrast with known medium-induced radiation, retains some properties of the vacuum case; in particular, it exhibits a soft divergency. However, as opposed to the vacuum, the collinear singularity is regulated by the pair opening angle, leading to a strict angular separation between vacuum and medium-induced radiation, denoted as antiangular ordering. We comment on the possible consequences of this new contribution for jet observables in heavy-ion collisions.

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Yacine Mehtar-Tani, Carlos A. Salgado, Konrad Tywoniuk. 2011-03-16. Antiangular Ordering of Gluon Radiation in QCD Media. https://doi.org/10.1103/physrevlett.106.122002

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