NPL News

Publishing during the pandemic

PhD student Travis Dore and Assistant Professor Jaki Noronha-Hostler wrote a paper on the effects of shear and bulk viscosity and their influence on the search for the Quantum Chromodynamics critical point. We used relativistic hydrodynamics and studied at what point hydrodynamics breaks down as one approaches a critical point and also how out out-of-equilibrium effects influence the search for the critical point. This was recently accepted for publication in Phys. Rev. D:
https://arxiv.org/pdf/2007.15083.pdf

PhD student Patrick Carzon and former Postdoc Dr. Matt Sievert (who recently left for a professorship at New Mexico State University) and Assistant Professor Jaki Noronha-Hostler published a paper on the possibility of a deformed 208^Pb nucleus. Most people assume lead 208 is spherical because it has double magic numbers but there is an unresolved puzzle in ultra-central heavy-ion collisions that a pear shape lead nucleus may resolve. However, from our study we find that it does not capture the correct fluctuations of the nucleus. This was accepted for publication in Phy Rev. C
https://arxiv.org/pdf/2007.00780.pdf
Published on 10/19/2020

ICASU Welcomes New Graduate Fellow

The Illinois Center for Advanced Studies of the Universe (ICASU) welcomes the first ICASU graduate fellow, Debora Mroczek. Debora joins Professor Jacquelyn Noronha-Hostler’s research group, where she will use machine learning to map the Quantum Chromodynamic (QCD) phase diagram. https://icasu.illinois.edu/news/icasu-welcomes-new-graduate-fellow
Published on 10/19/2020

Mr. Marco Meyer Successfully Defends Thesis

Mr. Marco Meyer, a graduate student at University of Paris-Saclay in France, has successfully defended his Ph.D thesis on November, 21st, 2019. Dr. Meyer's Ph.D thesis research was based on the COMPASS experiment at CERN. He led the effort to extract the absolute Drell-Yan cross sections using the 190 GeV pion beam on several targets. New information on the pion valence quark distributions as well as the nuclear modifications of parton distributions has been obtained from this research. Marco's Ph.D research supervisors are Dr. Stephane Platchkov at CEA Saclay, and Prof. Jen-Chieh Peng at UIUC. Marco spent one year at UIUC during 2018-2019 to complete the final phase of his Ph.D research. 
Author: Jen-Chieh Peng
Published on 11/25/2019

Nuclear Physics Laboratory - Updates

sPHENIX: Current EMCal block production per week is at 25. The complex production and testing chain work well, with a few quirks here and there. We have 22 undergrad students working on the project with an increasing trend. Recently, some of the students were assigned to help later stages (than early stage fiber filling) within the production chain.  Duties performed are mold cleaning, mold loading, and tungsten powder filling. The EMCal schedule anticipates production of 60 blocks per week beginning April or May 2020.
Author: Mike Suchor
Published on 11/15/2019

Dr. Robert Heitz successfully defends his thesis

Congratulations to Dr. Robert Heitz, who successfully defended his thesis on Tue. Apr. 30 before the committee of Liang Yang (chair), Matthias Perdekamp, Caroline Riedl (advisors), Alexey Bezryadin and John Stack. Dr. Heitz’s thesis, entitled “Transverse Momentum Dependent Nucleon Structure from Pions Impinged on a Transversely Polarized Proton Target” describes results from the data collected during the 2015 run of the COMPASS experiment at CERN: left-right asymmetries in Drell-Yan- or J/Psi-production with respect to the transverse target spin direction. Prior to analyzing the data, Dr. Heitz was part of the UIUC team that built a new drift chamber for COMPASS and he was responsible for aligning the several hundred tracking planes of COMPASS.
Author: C. Riedl
Published on 7/23/2019

Dr. Thomas Rao successfully defends thesis

Congratulations to Dr. Thomas Rao who successfully defended his thesis on Tue. Apr. 23 before the committee of Jen-Chieh Peng (chair), Doug Beck (advisor), Gordon Baym and Russ Giannetta.  Dr. Rao’s thesis, entitled “Transport of 3He for the nEDM experiment at the SNS” described the results of an experiment to measure the diffusion constant of 3He in superfluid 4He.  The experiment was carried out at the Harvard laboratory of Ike Silvera, and with the assistance of our technical staff: John Blackburn, Peter Sobel, Eric Thorsland together with Jaakko Koivuniemi and Steve Williamson from NPL, Weijun Yao from ORNL, and James Maxwell from MIT (now JLab).
Author: Prof. Doug Beck
Published on 4/26/2019

New results on sea-quark asymmetry from SeaQuest


The Fermilab SeaQuest experiment, designed to measure the light sea-quark flavor structure covering the large Bjorken-x region (up to x=0.45), has completed data-taking in July, 2016. The up and down sea-quark distributions are measured using 120 GeV proton beam interacting with liquid hydrogen and deuterium targets. The new result from an analysis of roughly half of the SeaQuest data was just announced in the Deep-Inelastic-Scattering Conference (April 8-12) in Italy. Jason Dove, a UIUC graduate student, presented this new result on behalf of the SeaQuest Collaboration. His talk can be found at:
https://indico.cern.ch/event/749003/contributions/3344635/attachments/1826425/2989273/DIS_slides_v14.pdf
The current UIUC members of the SeaQuest Collaboration include Jason Dove, Hugo Leung, Naomi Makins, Shivangi Prasad, Andrew Chen, and Jen-Chieh Peng
Author: Professor Jen-Chieh Peng
Published on 4/18/2019

A new review article on "Physics with Reactor Neutrinos"

A review article dedicated to the subject of "Physics with Reactor Neutrino", coauthored by Xin Qian at BNL and Jen-Chieh Peng at UIUC, was recently published in 'Report of Progress in Physics'. This article presents the history and highlights of reactor neutrino experiments, including the Daya Bay Neutrino Oscillation experiment, of which UIUC has been a member since inception. The review article, published in Rep. Prog. Phys. 82, 036201 (2019), can be found at:
https://arxiv.org/pdf/1801.05386.pdf
Author: Professor Jen-Chieh Peng
Published on 4/18/2019

Lepton angular distributions in Drell-Yan and Z-boson production

Two recent articles aiming at providing new insights on the origins of the lepton angular distribution in the Drell-Yan and vector-boson production were published. In a series of four articles, the long-standing puzzle of the origins of the violation of the "Lam-Tung" relation in the Drell-Yan process was explained using an intuitive "geometric" picture. This approach is currently being extended to other high-energy hard-scattering processes. The two latest articles appear in Phys. Lett. B789, 356 (2019) and Phys. Rev. D99, 014032 (2019). They can be found at:
https://arxiv.org/pdf/1811.03256.pdf
https://arxiv.org/abs/1808.04398.pdf
These latest papers were co-authored by Wen-Chen Chang, Oleg Teryaev, Daniel Boer, Jen-Chieh Peng (UIUC), Evan McClellan (former UIUC student, now at Jefferson Lab).
Author: Professor Jen-Chieh Peng
Published on 4/18/2019

A collision of light

Professor Anne Sickles is currently teaching a laboratory class at the University of Illinois in which her students will measure what happens when two photons meet. What they will find is that the overlapping waves of light get brighter when two peaks align and dimmer when a peak meets a trough. She tells her students that this is process called interference, and that—unlike charged particles, which can merge, bond and interact—light waves can only add or subtract. “We teach undergraduates the classical theory,” Sickles says. “But there are situations where effects forbidden in the classical theory are allowed in the quantum theory.”
Author: Sarah Charley
Published on 4/16/2019