Nuclear and Particle Physics Colloquium 60
Speaker: Junhui Liao (廖俊辉), senior scientist of Brown University
Title: Dark Matter (WIMPs) direct detection
Time: 10:00 am, September 30 (Sunday ), 2018
Speaker: Junhui Liao
Location:Main building 316
I will be talking about Dark Matter (DM) direct detection.
DM is one of the most important questions to be understood and answered in fundamental physics. Among other DM candidates,
Weakly Interactive Massive Particles (WIMPs) is the most discussed one. WIMPs direct detection is a research of multi-disciplines which wraps astrophysics,
particle physics and nuclear physics together and able to explore the un-touched region of the interaction between WIMPs and nucleons in a way other methods
like indirect detection and the searches on colliders can't reach.
I will firstly review the search of DM: the evidence of its existence, the strategy of detection, the current results from various experiments etc.
Secondly, two DM direct experiments will be addressed in details: DArk Matter In CCDs (DAMIC) and LUX-ZEPLIN (LZ) which hunt for low-mass (~ 1 - 10 GeV/c^2)
and high-mass (~ 10 - 1000 GeV/c^2) WIMPs, respectively. For DAMIC, I will be talking about the quenching factor calibration for a silicon detector and the understanding
for the interaction between WIMPs and nucleons under the context of Effective Field Theory (EFT). LZ is the most sensitive WIMPs searching detector at the stage
of construction and has been fully funded by Department of Energy (DOE), USA. I will introduce the project a little bit, the progress of the assembly of PMT arrays
at Brown and the Geant simulation for a calibration of Liquid Xenon (LXe) with 300 keV neutrons.
At the end, I will be presenting a preliminary proposal for low-mass (~ 1 - 10 GeV/c^2) WIMPs hunting with instrumental-backgrounds free thanks
to Pulse Shape Discrimination (PSD): A Liquid HEllium Single phase TPC (ALHEST). With ~ 100 kg* yr exposure, ALHEST would achieve the region
of WIMPs-nucleon scattering never-before explored. ALHEST can be scaled up to ton or multi-tonnes therefore is capable of searching for B-8 solar neutrinos.
Cooling Liquid Helium (LHe) down to superfluid phase, with further R&D on the responses of the detector to phonons / rotons, ~ MeV/c^2 DM would be able to be hunted.
Mar 2018 - present, Senior scientist, Brown University.
Feb 2017 - Feb 2018, post doc, Brown University.
July 2013 - Dec 2016, PhD, University Zurich, Switzerland.
Mar 2014 - Dec 2015, visiting scholar, Fermilab.
Mar 2009 - Jan 2013, Research assistant, UCLouvain, Belgium.
Sep 2005 - Mar 2009, Joint master student and primary researcher, EPC, IHEP.
Sep 2007 - Dec 2007, visiting scholar, LNF, INFN.