Research Expertise and Interest

physics, high energy physics, dark matter, dark energy, precision measurements, data science, Educational Data Science

Research Description

Fundamental particle physics, particularly from the experimental perspective, is Bob Jacobsen's primary research interest. Over the past 20 years the “Standard Model” of high energy physics has triumphed in precise tests of predictions of various quantities. The next step is to learn more about the unknown parameters, particularly in the neutrino sector, and to search for hints to the remaining phenomenological mysteries: Dark Energy and Dark Matter.

The large particle colliders and their experiments provides one powerful approach to these next steps.  But it’s also possible to make progress with smaller projects that address specific questions.  For example, a number of different techniques are being used, and new ones are being proposed, for experimental searches for dark matter.  His interest lies with using very quiet targets, for example heavily-shielded and high pure targets of liquid Xenon, and watching them with high-sensitivity phototube arrays to detect possible interactions with dark matter particles as they transit through the Earth. Much like the initial solar neutrino experiments of decades ago, this is an exercise in careful understanding of backgrounds and observation of very small, low-rate signals with high confidence levels.  Experimentally, it’s hard, but also a lot of fun.  From a physics perspective, confirmed observations of dark matter particles would open up an entirely new window on fundamental physics.

Current Projects

The LZ detector is located 4850 feet underground at the Homestake Mine in Lead, South Dakota. In 2013 through 2019 it's LUX predecessor published the best-yet limits on WIMP-type dark matter. This 6+ tonne liquid Xenon detector is being installed in the cavern in 2020, and will provide a large improvement in sensitivity.  We expect “first dark”, the initial operation, some time in late 2020 or 2021.