NPL News Now

November 25, 2019
Mr. Marco Meyer Successfully Defends Thesis


sPHENIX
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.

November 18, 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.
The first of two deliveries of tungsten powder arrived this week. 5.2 tons; 26 blue metal drums, you can't miss them when you enter the high bay! Some of the palettes will be stored in the metal shed. Delivery #2 is expected November 26.

nEDM
We are planning another cooldown before year end. The dilution refrigerator cryostat will not be opened before that cooldown - it will be a repeat of the last cooldown which had issues because of ice-blocked capillaries.
Effort to put the tube furnace together. We estimate testing next week. Finishing up film burner assembly during tube furnace construction. Some fixture parts will be made in our shop. Parts for the Depol IVC re-build are researched and pending quotes. In the meantime, we will try to dissect one of the sinter tubes and then examine the inner and outer sinter with a microscope. We will also try to BET test un-sintered powder as a test of our surface area measurement system.
We will attempt to glue seamless Kapton tubing to the interior of a copper shell as a test of the technique planned for the fabrication of the injection volume for the next piece of hardware. Hardware will be fabricated on site once we are satisfied with tests and the film burner.

July 23, 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.

April 26, 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).

April 18, 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

April 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

April 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).