NPL News Now

May 25, 2017
phYSics Young Scholars program to begin summer of 2017

The phYSics Young Scholars program will welcome 10 rising junior and senior high school students from the local area to examine, explore and consider exciting careers in scientific research. The 6 week summer program will give hands on experience to help students better fathom how we ask and answer questions in science. Young Scholars will be embedded in cutting-edge research laboratories at the Physics Department within the College of Engineering. They will be introduced to a variety of live experiments and scientific research as well as the ability to gain an understanding of science and its local and global impact. Young Scholars will have opportunities to build relationships with college students, professors, and other high school students. Visit the phYSics Young Scholars page for more information.

April 24, 2017
COMPASS publishes first hint of sign change in Drell-Yan Sivers function

The COMPASS collaboration at CERN submitted their 2015 measurement for publication in Physical Review Letters. The Sivers amplitude from the 2015 COMPASS spin-dependent Drell-Yan data provides the first hint of a sign change of the Sivers function measured in Drell-Yan (DY) as compared to measured in Semi-Inclusive Deep-Inelastic scattering (SIDIS). This sign change is a fundamental prediction of Quantum Chromo Dynamics, or QCD, the underlying theory of the strong interaction between quarks in the proton. The sign change is a milestone of the Nuclear Science Advisory Committee (NSAC). The Sivers function is one of the proton's Transverse-Momentum Dependent parton distributions (TMDs) and describes the correlation between the transverse spin of the parent proton and the transverse momentum of the probed quark. COMPASS has previously measured the Sivers amplitude in SIDIS and is therefore in the unique situation to conclude on the sign change without involving uncertainties related to TMD evolution.
The UIUC COMPASS group has significantly contributed to the success of the measurement in terms of instrumentation, coordination and data analysis. The Illinois authors are: Vincent Andrieux, Ihn-Jea Choi, Francesca Giordano, Robert Heitz, Jaakko Koivuniemi, Yakov Kulinich, Alain Magnon, Naomi Makins, Marco Meyer, Jen-Chieh Peng, Matthias Grosse Perdekamp, and Caroline Riedl. The arXiv version of the paper is available here: https://arxiv.org/abs/1704.00488.
A second COMPASS run of spin-dependent DY in 2018 will enhance the statistical significance of the measurement.

April 6, 2017
sPHENIX 2016 Test Beam Paper submitted

The sPHENIX combined calorimeter test beam paper from the 2016 Fermilab test has been submitted to the IEEE Transaction of Nuclear Science. The electromagnetic calorimeter was built half at the NPL and half at Tungsten Heavy Powder with finishing work done at the NPL. The Illinois group also led the analysis of the electromagnetic calorimeter performance. Facilities at the MRL were used by to characterize the properties of the tungsten powder used in the calorimeter. The Illinois contribution (over 20% of the authors) was the largest of any institution except for Brookhaven’s. The Illinois authors are: Virginia Bailey, John Blackburn, Michael Higdon, Simon Li, Vera Loggins, Mike Phipps, Anne Sickles, Peter Sobel, and Eric Thorsland. The tested calorimeters were found to meet the sPHENIX physics requirements. The paper is available here: https://arxiv.org/abs/1704.01461

March 16, 2017
4th year of CCD funding approved for nEDM project

On Mar. 15 we received word from NSF that the final year of funding for the Critical Component Demonstration phase of the neutron electric dipole moment experiment (nEDM) is approved for release. The Illinois group (Beck, Peng, Williamson, Koivuniemi, Thorsland, Blackburn, Sobel, Rao, Sharma) is responsible for the so-called helium-3 services subsystem of the experiment. These funds will allow us to complete the dilution refrigerator, under construction at NPL, and used to cool the subsystem, as well as to make progress on components of both its injection and purification assemblies. The NSF also re-stated its commitment to provide $5.8M for the Large Subsystem Integration activities to follow the CCD phase of the experiment and to be shared between Illinois and Caltech.

February 21, 2017
Testing cryogenic electronics for nEXO

As a next-generation tonne scale double beta decay experiment, nEXO requires new development in detector technology. One key area is the development of low noise front-end electronics that can operate directly in liquid xenon (~170 K). In collaboration with the Brookhaven National Lab, students Shaolei Li and Xuanying Li are testing the performance of prototype boards built with custom ASICs. In the coming weeks, they will develop codes to readout all channels of the board and analyze the noise correlation between different channels. The board will later be used in liquid xenon test setups by the collaboration.