scholarly journals ON ANGULAR ORDERING IN MEDIUM-INDUCED RADIATION

2011 ◽  
Vol 20 (07) ◽  
pp. 1600-1604
Author(s):  
KONRAD TYWONIUK
Keyword(s):  
Perturbative Qcd ◽  
First Principles ◽  
Heavy Ion Collisions ◽  
Heavy Ion ◽  
Differential Spectrum ◽  
Opening Angle ◽  
Gluon Emission ◽  
Collinear Singularity ◽  
Ion Collisions ◽  
Jet Observables

As an attempt to understand color coherence effects in medium from first principles, we calculate the double differential spectrum of medium-induced gluon emission off a quark–antiquark antenna in the framework of perturbative QCD. Within this setup we find a soft singularity, analogous to the vacuum spectrum, yet, as opposed to the vacuum, the collinear singularity is regulated by the pair opening angle, leading to a strict anti-angular ordering. We comment on the possible consequences of this new contribution for reconstructed jet observables in heavy-ion collisions.

scholarly journals Heavy and light flavor jet quenching in heavy-ion collisions in a perturbative QCD approach

2021 ◽  
Vol 1005 ◽  
pp. 121829
Author(s):  
Wen-Jing Xing ◽  
Shanshan Cao ◽  
Guang-You Qin ◽  
Hongxi Xing
Keyword(s):  
Perturbative Qcd ◽  
Heavy Ion Collisions ◽  
Heavy Ion ◽  
Jet Quenching ◽  
Ion Collisions

scholarly journals Medium response to jets in heavy ion collisions

2018 ◽  
Vol 172 ◽  
pp. 05009
Author(s):  
Yasuki Tachibana
Keyword(s):  
Heavy Ion Collisions ◽  
Recent Progress ◽  
Heavy Ion ◽  
Jet Quenching ◽  
Short Overview ◽  
Ion Collisions ◽  
Jet Observables ◽  
Work Done

A short overview on recent progress in studies of medium response to jet quenching in heavy ion collisions is presented. We show the typical features of medium response and give comment on their connection to jet observables by introducing the work done by the author and collaborators as an example.

ARE NARROW POSITRON-ELECTRON LINES CREATED BY DECAY OF EXCITED VACUUM-LIKE SYSTEMS FORMED FROM A COHERENT PIONIC PHASE PRESENT IN HEAVY-ION COLLISIONS?

1992 ◽  
Vol 07 (20) ◽  
pp. 1843-1853 ◽  
Author(s):  
SAUL BARSHAY
Keyword(s):  
Heavy Ion Collisions ◽  
Electron Pair ◽  
Experimental Tests ◽  
Heavy Ion ◽  
Opening Angle ◽  
Vacuum Condensate ◽  
Final State ◽  
Correlated Electron ◽  
Ion Collisions ◽  
Electron Positron

A novel description of several narrow, correlated electron-positron lines observed in heavy-ion collisions, arises from a physical picture involving the decay of a group of related, excited coherent bosonic states, which resemble an excited, chira σ vacuum-condensate. These systems are formed in the collision of a coherent pionic phase present in the heavy ions. Further experimental tests of the idea, involve the specific form of the opening angle correlation between the positron-electron pair, and possibly, the nature of the charge states of the final-state ions.

scholarly journals Deep learning jet modifications in heavy-ion collisions

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Yi-Lun Du ◽  
Daniel Pablos ◽  
Konrad Tywoniuk
Keyword(s):  
Deep Learning ◽  
Transverse Momentum ◽  
Energy Loss ◽  
Heavy Ion Collisions ◽  
Heavy Ion ◽  
Loss Ratio ◽  
Ion Collisions ◽  
Learning Techniques ◽  
Jet Observables ◽  
The Impact

Abstract Jet interactions in a hot QCD medium created in heavy-ion collisions are conventionally assessed by measuring the modification of the distributions of jet observables with respect to the proton-proton baseline. However, the steeply falling production spectrum introduces a strong bias toward small energy losses that obfuscates a direct interpretation of the impact of medium effects in the measured jet ensemble. Modern machine learning techniques offer the potential to tackle this issue on a jet-by-jet basis. In this paper, we employ a convolutional neural network (CNN) to diagnose such modifications from jet images where the training and validation is performed using the hybrid strong/weak coupling model. By analyzing measured jets in heavy-ion collisions, we extract the original jet transverse momentum, i.e., the transverse momentum of an identical jet that did not pass through a medium, in terms of an energy loss ratio. Despite many sources of fluctuations, we achieve good performance and put emphasis on the interpretability of our results. We observe that the angular distribution of soft particles in the jet cone and their relative contribution to the total jet energy contain significant discriminating power, which can be exploited to tailor observables that provide a good estimate of the energy loss ratio. With a well-predicted energy loss ratio, we study a set of jet observables to estimate their sensitivity to bias effects and reveal their medium modifications when compared to a more equivalent jet population, i.e., a set of jets with similar initial energy. Finally, we also show the potential of deep learning techniques in the analysis of the geometrical aspects of jet quenching such as the in-medium traversed length or the position of the hard scattering in the transverse plane, opening up new possibilities for tomographic studies.

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