The Grainger College of Engineering
Nuclear Physics Group

ATLAS

ATLAS Research Project

http://atlas.ch/
CERN - Geneva, Switzerland

The Illinois group on the ATLAS experiment is studying the structure of quark gluon plasma (QGP) produced in the collisions of large nuclei using jets. These measurements provide unique information about the short range interactions between quarks and gluons from which the low viscosity liquid behavior of the QGP must arise. The high collision energies at the LHC provide access to the largest kinematic range and highest rates of jets produced in heavy ion collisions.  

For more about the ATLAS Heavy Ion program and it’s motivations see the recent ATLAS feature article (https://atlas.cern/Updates/Feature/Heavy-Ion-Physics) co-authored by Prof. Sickles and the youtube live talk (https://www.youtube.com/watch?v=5lAtJ6Lfbmo). For more about using jets to study the QGP see the recent review article co-authored by Prof. Sickles (https://inspirehep.net/literature/1953399).

We are also interested in measurements of proton-nucleus and proton-proton collisions both as reference systems for nucleus-nucleus collisions and as a place to look for the color glass condensate. We also use proton-nucleus collisions to study cold nuclear matter effects on the nucleon structure and to investigate fluctuations in the proton's size and interaction strength. 

Our group takes an active role in ATLAS data-taking, with group members typically traveling to CERN for periods during the heavy-ion running.  We have been involved in the trigger operation and validating the data quality.  In January 2020, we hosted an ATLAS Heavy Ion Jet Workfest in Urbana.

Our group is also playing a leading role in the operations of the current ATLAS Zero Degree Calorimeter (ZDC), in the design and construction of a new Reaction Plane Detector (RPD) for ATLAS heavy ion program in Run 3, and in the joint ATLAS-CMS ZDC Upgrade project, that will design and construct the next generation of radiation-hard ZDCs & RPDs for the High-Luminosity LHC era. 

Former members of our group have gone onto faculty and staff positions, postdocs at universities and labs and industry jobs.

Papers written primarily by members of our group include:

sPHENIX/ATLAS Interview

Faculty on this project

Riccardo Longo
Research Scientist

Post-Docs on this project

Grad students on this project

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Figure 1: Graduate Student Michael Phipps and  Post-Doctoral Research Associate Sebastian Tapia Araya in the ATLAS Control Room during the 2018 Heavy Ion data taking. 

Support of Heavy Ion
Runs at CERN 

Our group actively support all the Heavy Ion related data taking (A+A, p+A and low-u p+p) with on-site presence of graduate students and post-docs. 

Figure 2: Post-Doctoral Research Associate Riccardo Longo installing the ATLAS ZDC in the LHC for the joint ZDC-LHCf run during September 2022. 
Figure 2: Post-Doctoral Research Associate Riccardo Longo installing the ATLAS ZDC in the LHC for the joint ZDC-LHCf run during September 2022. 

 

Figure 2: from left to right Graduate Student Matthew  Housenga, Post-Doctoral Research Associate Riccardo Longo, Undergraduate Student Farah Mohammed Rafee, and Graduate Students Chad Lantz and Mason Housenga
Figure 3: from left to right Graduate Student Matthew Hoppesch, Post-Doctoral Research Associate Riccardo Longo, Undergraduate Student Farah Mohammed Rafee, and Graduate Students Chad Lantz and Mason Housenga

Test beams at CERN and FermiLab 

We run test beam campaign at CERN and FNAL to calibrate existing ZDC and RPD detectors and to test new radiation-hard prototypes to be used for ATLAS and CMS in the HL-LHC era 

Figure 4: Graduate Student Akshat Puri presenting results from his analysis in a poster session at Quark Matter 2018 hosted in Venice, Italy
Figure 4: Graduate Student Akshat Puri presenting results from his analysis in a poster session at Quark Matter 2018 hosted in Venice, Italy

Students and Post-Docs travel to discuss their work at international conferences and meetings