In-medium loop corrections and longitudinally polarized gauge bosons in high-energy showers

Journal Article · Wed Dec 19 00:00:00 EST 2018 · Journal of High Energy Physics (Online)

DOI:https://doi.org/10.1007/JHEP12(2018)120· OSTI ID:1611005

Arnold, Peter ^[1]; Iqbal, Shahin ^[2]

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1. Univ. of Virginia, Charlottesville, VA (United States)
2. Quaid-i-Azam Univ. (Pakistan)

The splitting processes of bremsstrahlung and pair production in a medium are coherent over large distances in the very high energy limit, which leads to a suppression known as the Landau-Pomeranchuk-Migdal (LPM) effect. We continue study of the case when the coherence lengths of two consecutive splitting processes overlap (which is important for understanding corrections to standard treatments of the LPM effect in QCD), avoiding soft-emission approximations. In this particular paper, we show (i) how the “instantaneous” interactions of Light-Cone Perturbation Theory must be included in the calculation to account for effects of longitudinally-polarized gauge bosons in intermediate states, and (ii) how to compute virtual corrections to LPM emission rates, which will be necessary in order to make infrared-safe calculations of the characteristics of in-medium QCD showering of high-energy partons. In order to develop these topics in as simple a context as possible, we will focus in the current paper not on QCD but on large-N_f QED, where N_f is the number of electron flavors.

• Research Organization: Univ. of Virginia, Charlottesville, VA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), High Energy Physics (HEP)
• Grant/Contract Number: SC0007984
• OSTI ID: 1611005
• Journal Information: Journal of High Energy Physics (Online), Vol. 2018, Issue 12; ISSN 1029-8479
• Publisher: Springer Berlin
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
Quark-Gluon Plasma
Perturbative QCD