Feb 5 – 11, 2017
Hyatt Regency Chicago
America/Chicago timezone

Holographic jet shapes and their evolution in strongly coupled plasma

Feb 7, 2017, 12:00 PM
Regency D

Regency D


Jasmine Brewer (MIT)


Recently our group analyzed how the probability distribution for the jet
opening angle is modified in an ensemble of jets that has propagated
through an expanding cooling droplet of plasma [1]. Each jet in the
ensemble is represented holographically by a string in the dual 4+1-
dimensional gravitational theory with the distribution of initial energies and
opening angles in the ensemble given by perturbative QCD. In [1], the full
string dynamics were approximated by assuming that the string moves at
the speed of light. We are now able to analyze the full string dynamics for
a range of possible initial conditions, giving us access to the dynamics of
holographic jets just after their creation. We show that, after a period of
time that we compute, the string nullifies: the force of gravity accelerates
each section of string until it approaches the speed of light. The
nullification timescale and the features of the string when it has nullified
are all results of the string evolution. This emboldens us to analyze the full jet shape, rather than just the opening angle of each jet in the ensemble as in [1]. We find the
striking result that the jet shape scales with the opening angle at any
particular energy. We construct an ensemble of dijets with energies and
energy asymmetry distributions taken from events in proton-proton
collisions, opening angle distribution as in [1], and jet shape taken from
proton-proton collisions and scaled according to our result. We study how
all of these observables are modified after we send the ensemble of dijets
through the strongly-coupled plasma.

[1] Krishna Rajagopal, Andrey V. Sadofyev, Wilke van der Schee, "Evolution of the jet opening angle distribution in holographic plasma", PRL 116, 211603 (2016)

Collaboration Not applicable
Preferred Track Jets and High pT Hadrons

Primary author

Presentation materials