Talks & Events
KICP Wednesday Colloquia - Usually Wednesdays, 3:30 PM, ERC 161, unless otherwise specified. Reception starts at 4:30 PM in ERC 161. For more information visit the KICP website.
Current & Future KICP Colloquia
Past KICP Colloquia
Searching for Dark Matter With Bubble Chambers
PDF | Video
Development of bubble chamber detectors for WIMP dark matter was pioneered at KICP in the early 2000’s. In the intervening years, we scaled the technology from the initial test-tube sized detectors operated in the basement of the LASR building to a 60 kg chamber now installed 2-km underground at SNOLAB. I will review the history of these developments and the most recent results from the PICO-2L and PICO-60 experiments.
Quantum Twists of Space: Exotic Rotational Correlations from Quantum Geometry, Their Effects on Interferometer Signals, and Their Connection with Cosmic Acceleration
PDF | Video
The talk will review theoretical arguments that if space and time emerge from a quantum system at the Planck scale, there should be nonlocal exotic quantum correlations of positions of massive bodies, even on scales much larger than the Planck length. In relational theories with no fixed background space, these could take the form of rotational quantum fluctuations in the inertial frame. Basic quantum principles are used to derive their effect on correlations in the signals of interferometers. An experimental test is proposed, based on a reconfiguration of the Fermilab Holometer. It is conjectured that entanglement of these rotational correlations with the Standard Model vacuum could explain the value of the cosmological constant in terms of known scales of physics.
Improved Limits from the Large Underground Xenon Dark Matter Experiment
A wealth of astrophysical research supports the existence of dark matter in the universe, yet the exact identity and nature of this unknown particle remain elusive. The Large Underground Xenon (LUX) dark matter search is a 370-kg xenon-based time projection chamber (TPC) that operates by detecting light and ionization signals from particles incident upon a xenon target. With the 2013 report of the world’s first sub-zeptobarn spin-independent WIMP-nucleon cross section limit, the LUX (Large Underground Xenon) experiment emerged as a frontrunner in the field of dark matter direct detection. In December 2015, LUX released an updated analysis of its 2013 dataset with increased detector exposure, updates to the background model, upgraded event reconstruction algorithms, and novel calibrations leading to an overall 23% increase in sensitivity for high-mass WIMPs and even more significant improvements for low-mass WIMPs. This talk details the design of the LUX experiment and reviews the analysis and reanalysis of the 2013 dataset leading to the world’s most stringent constraints on spin-independent WIMP-nucleon scattering for WIMPs above mass 4 GeV.
New Approaches to Dark Matter
In this talk I will discuss a novel theory of superfluid dark matter. The scenario matches the predictions of the LambdaCDM model on cosmological scales while simultaneously reproducing the MOdified Newtonian Dynamics (MOND) empirical success on galactic scales. The dark matter and MOND components have a common origin, as different phases of a single underlying substance. This is achieved through the rich and well-studied physics of superfluidity. The framework naturally distinguishes between galaxies (where MOND is successful) and galaxy clusters (where MOND is not): due to the higher velocity dispersion in clusters, and correspondingly higher temperature, the DM in clusters is either in a mixture of superfluid and normal phases, or fully in the normal phase. The model makes various observational predictions that distinguishes it from both LambdaCDM and standard MOND. In the last part of the talk, I will discuss an on-going attempt at explaining cosmic acceleration as yet another manifestation of dark matter superfluidity.