Anne M Sickles

Associate Professor


Anne M Sickles

Primary Research Area

  • Nuclear Physics
403 Loomis Laboratory

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Professor Sickles received her bachelor's degree in physics from Gonzaga University in 2001 and her Ph.D. in physics from Stony Brook University in 2005. She was a postdoctoral researcher at Brookhaven National Lab from 2005 to 2009. In 2009 she joined the scientific staff of Brookhaven first as an Assistant Physicist and then Associate Physicist (2011). She joined the Department of Physics at the University of Illinois as an assistant professor in 2014.

Professor Sickles' research is in the field of relativistic heavy ion collisions. She is the convener of the ATLAS Heavy Ion Working Group (2018-2020) at the Large Hadron Collider at CERN and a member of the sPHENIX Experiment at the Relativistic Heavy Ion Collider at Brookhaven.

Research Statement

My research is focused on experimental studies of the matter created in relativistic heavy ion collisions, the quark gluon plasma. This matter is created when temperatures are sufficiently high that colorless hadrons are no longer the relevant degrees of freedom. This matter is characterized by strong interactions between the constituents and is better described as a liquid than a gas.

Recently, evidence of fluid-like behavior in proton-Pb collisions at the LHC was found. This was not expected given that any initial system has a size no bigger than the size of the smaller nucleus. The signature test of this is to vary the geometry of the initial collision region by changing the initial geometry of the system. I led the first measurement to do this by analyzing deuteron-Au collisions at PHENIX. In this case the elongated geometry of the deuteron would lead to an elliptic initial shape for the QGP. We found evidence for this in the particle correlations and the result was published in Phys. Rev. Lett. Taking this further I am interested in He3-Au collisions in which the initial QGP would have a triangular shape. Investigating the small size limit of the QGP provides a new frontier in determining its properties and particularly how the matter itself is formed on such a short timescale.

High energy jets from the hard scattering of quarks and gluons are a very powerful tool with which to study the QGP. In heavy ion collisions the jets propagate through the plasma and the jets are found to "lose" energy during this process. Of course the energy isn't gone, but it is moved away from the jet axis. My group has measured how the jets are modified and where particles are, both within and around the jets, this information is key to understanding the modification of the jets by the QGP and how the QGP reacts to the presence of a jet. The wealth of ATLAS data from Run 2 allow more detailed studies of jets.

My group also works on the the sPHENIX detector. sPHENIX is a new detector at RHIC which is expected to start data taking in 2023. It is designed specifically to measure jets and will allow direct comparisons with jet measurements at the LHC. Illinois is the primary construction site for the electromagnetic calorimeter blocks.

It will be especially exciting to have measurements at both RHIC and the LHC. The different collision energies mean different initial temperatures are achieved in the collisions. Jet quenching measurements at both colliders provide the best path to constrain the physics of jet quenching.

Semesters Ranked Excellent Teacher by Students

Spring 2015PHYS 211

Selected Articles in Journals

Related news

  • In the Media
  • Research
  • High Energy Physics

Sickles is a collaborator on the ATLAS experiment at CERN and studies what happens when particles of light meet inside the Large Hadron Collider. For most of the year, the LHC collides protons, but for about a month each fall, the LHC switches things up and collides heavy atomic nuclei, such as lead ions. The main purpose of these lead collisions is to study a hot and dense subatomic fluid called the quark-gluon plasma, which is harder to create in collisions of protons. But these ion runs also enable scientists to turn the LHC into a new type of machine: a photon-photon collider.

  • Research
  • High Energy Physics
  • Particle Physics
The lead ion run is under way. On 8 November at 21:19, the four experiments at the Large Hadron Collider - ALICE, ATLAS, CMS and LHCb - recorded their first collisions of lead nuclei since 2015. For three weeks and a half, the world’s biggest accelerator will collide these nuclei, comprising 208 protons and neutrons, at an energy of 5.02 teraelectronvolts (TeV) for each colliding pair of nucleons (protons and neutrons). This will be the fourth run of this kind since the collider began operation. In 2013 and 2016, lead ions were collided with protons in the LHC.

Anne Sickles is co-convener of the ATLAS Heavy Ion Working Group, which will use these data.
  • Research
  • Nuclear Physics

Tracking particles created in subatomic smashups takes precision. So before the components that make up detectors at colliders like the Relativistic Heavy Ion Collider (RHIC) get the chance to see a single collision, physicists want to be sure they are up to the task. A group of physicists and students hoping to one day build a new detector at RHIC—a DOE Office of Science User Facility for nuclear physics research at the U.S. Department of Energy’s Brookhaven National Laboratory—recently spent time at DOE’s Fermi National Accelerator Laboratory putting key particle-tracking components to the test.

  • Research
  • Nuclear Physics

Scientists at Brookhaven National Laboratory will work to understand the emergent properties of the superhot primordial soup called "quark-gluon plasma" (QGP), generated at the Relativistic Heavy Ion Collider (RHIC). QGP's perfect fluidity and other collective properties are a mystery.To address that mystery, a group of nuclear physicists has formed a new scientific collaboration that will expand on discoveries made by RHIC’s existing STAR and PHENIX research groups. This new collaboration, made up of veterans of the field and researchers just beginning their careers, has precise ideas about the measurements its members would like to make—and hopes of upgrading the PHENIX detector to make those measurements at RHIC.