# High Energy Physics Seminars

**Join Zoom Meeting:**##### https://virginia.zoom.us/j/92287909487

**Meeting ID:** 922 8790 9487

**Password:** HEPseminar

**Meeting ID:**

**Password:**Wednesday, April 21, 2021

4:00 PM

Online, Room via Zoom

Note special room.

## "Is double gluon bremsstrahlung in a quark-gluon plasma accurately described by the N_{color} = ∞ approximation to QCD?"

**Omar Elgedawy , University of Virginia - Department of Physics**

[Host: Peter Arnold]

ABSTRACT:

QCD jets produced from colliding two heavy nuclei play an important role in understanding properties of the Quark Gluon Plasma produced in these energetic collisions. During their travel through the medium, high energy partons lose their energy due to interactions with the medium through elastic collisions and medium-induced splitting processes like bremsstrahlung and pair production. In the high energy limit, these splitting processes are coherent over large distances and can no longer be treated as quantum mechanically independent, leading to a suppression of the splitting rate known as the Landau-Pomeranchuk-Migdal effect. An important question that arises is whether consecutive splittings of the high energy particle overlap within the formation time of an individual splitting. This case has been analyzed in the

*N*_{c}= ∞ limit within the thick medium approximation. To see if this result applies for real QCD with*N*_{c}= 3, we calculate the next to leading order correction (i.e. O(1/*N*^{2})) to the gluon double-splitting. We have already completed a subset of the diagrams known as*sequential*diagrams. In this talk, I will report first results on whether the*N*_{c}= ∞ approximation to the differential rate of overlapping double bremsstrahlung of gluons is reliable, and in particular whether the correction is large or small compared to the naive expectation of 1/*N*2c`∼`

10% for N_{c}= 3.VIDEO:

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