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Article
Report number	arXiv:1308.2186 ; CERN-PH-TH-2013-171 ; CERN-PH-TH-2013-171
Title	Coherence phenomena between initial and final state radiation in a dense QCD medium
Author(s)	Armesto, Néstor (Santiago de Compostela U., IGFAE ; CERN) ; Ma, Hao (Santiago de Compostela U., IGFAE) ; Martinez, Mauricio (Santiago de Compostela U., IGFAE ; CERN) ; Mehtar-Tani, Yacine (Saclay, SPhT) ; Salgado, Carlos A. (Santiago de Compostela U., IGFAE)
Publication	2013
Imprint	09 Aug 2013
Number of pages	34
Note	Comments: 33 pages, 2 figures. Fix typos and updated references. Discussion in the introduction updated. Accepted for publication in JHEP 34pages, 2 figures. Fixed typos and updated references. Discussion in the introduction updated.
In:	JHEP 12 (2013) 052
DOI	10.1007/JHEP12(2013)052
Subject category	Particle Physics - Phenomenology
Abstract	In this work we investigate medium modifications to the interference pattern between initial and final state radiation. We compute single gluon production off a highly energetic parton that undergoes a hard scattering and subsequently crosses a dense QCD medium of finite size. We extend our previous studies obtained at first order in opacity by providing general results for multiple soft scatterings and their specific formulation within the harmonic oscillator approximation. We show that there is a gradual onset of decoherence between the initial and final state radiation due to multiple scatterings, that opens the phase space for large angle emissions. By examining the multiplicity of produced gluons, we observe a potentially large double logarithmic enhancement for dense media and small opening angles. This result points to a possible modification of the evolution equations due to a QCD medium of finite size. We briefly comment on the phenomenological consequences of this setup in high-energy nuclear collisions.
Copyright/License	Preprint: © 2013-2025 CERN (License: CC-BY-3.0)

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