Title: First Results from the PandaX-I Experiment

Speaker: Prof. LIU Jianglai(Shanghai Jiaotong University)

Moderator: Prof. CAO Jun

Time: 10:00 AM, October 15, 2014

Place: Room B326

Abstract:

Many astrophysical phenomena have strongly indicated the existence of the dark matter (DM) through gravitational effects, but the particle physics nature of the DM remains elusive. Weakly interacting massive particles (WIMPs), a leading candidate of the DM, are theoretically motivated particles naturally arising from the physics beyond the Standard Model. Many experimental techniques are being developed aiming to directly detect WIMP-nuclear scattering via the nuclear recoils. Dual phase xenon time projection chamber (TPC) has emerged as one of the most promising technology, particularly sensitive to WIMPs at typical electroweak scale of the order 100 GeV/c2.

The PandaX experiment, located in the China Jin-Ping Underground Laboratory, utilizes the dual phase xenon technology. PandaX-I, the first phase detector with 120 kg active mass, is currently under operation. To achieve low energy threshold, the TPC of PandaX-I is specially designed to optimize the light collection. PandaX-II, the next phase detector with 500 kg active mass, is being prepared as the near future upgrade. In this talk, after a brief overview, I will discuss the design and performance of PandaX-I, and report its first dark matter results with a 37x17.4 kg-day exposure.

About the speaker:

Jianglai Liu was an undergraduate at the Nanjing University, and obtained his Ph.D. in 2006 at the University of Maryland. He was a postdoctoral research fellow at Caltech (2006-2010). He joined the faculty of Physics at the Shanghai Jiao Tong University since 2010, and was selected into the “1000 Young Talent Program” in China. Liu has worked on various experiments in the intersections of nuclear, particle, and astrophysics. He studied the strange form factors of the nucleon at the Jefferson Laboratory via parity-violating electron scattering (G-zero, 1999-2006), and performed measurements of the axial-vector coupling constant using ultracold neutron decays at the Los Alamos National Laboratory (UCNA, 2006-2010). Currently he is the PI of the neutrino physics group at the SJTU, involved in the Daya Bay and JUNO neutrino experiments. Since 2010 Liu started his journey on the PandaX experiment, a xenon-based direct dark matter search, and is presently serving as the deputy spokesperson of the project.