Experimental Particle Physics
We are engaged in a wide variety of experiments, including the search for dark matter, collider physics, lepton flavor violation and the study of charm mesons. Details for each experiment are given below.
Searches for Dark Matter
PICO - E.Dahl
The PICO collaboration builds bubble chambers for the direct detection of dark matter in the form of WIMPs (Weakly Interacting Massive Particles). These detectors, deployed 6800 feet below ground at SNOLAB in Sudbury, Ontario, lead the field in sensitivity to the spin-independent WIMP-proton coupling and have the unique capability to operate with a wide variety of target materials, giving them unmatched versatility in searching for (and studying) the WIMP signal.
LZ - E.Dahl
The LZ experiment is a 7-ton dual-phase xenon time projection chamber, to be deployed in 2019 in the Sanford Underground Research Facility in Lead, South Dakota. The successor to LUX, the current leader in sensitivity to the spin-independent WIMP-nucleon cross section, LZ has been selected as the primary US direct detection experiment for the upcoming generation of dark matter searches.
SuperCDMS - E. Figueroa-Feliciano
SuperCDMS SNOLAB is a second-generation dark matter experiment, to be built 2 km underground at the SNOLAB facility in Sudbury, Canada. This experiment will have unparalleled sensitivity to a class of dark matter candidates called WIMPS (Weakly-Interacting-Massive-Particles) for WIMP masses around one to a few times the mass of the proton. CDMS stands for Cryogenic Dark Matter Search; we use crystals cooled to milliKelvin temperatures and detect the energy deposited in them when a particle recoils off one of the atoms in the detector. We have strong ties to the Fermilab SuperCDMS group and will play a leading role in the commissioning of this experiment, a large part of which will happen at Fermilab before being sent down to SNOLAB.
Micro-X - E. Figueroa-Feliciano
Micro-X is a NASA-funded sounding rocket payload that uses a high-energy-resolution X-ray spectrometer with very similar detector technology as SuperCDMS, but optimized for detecting X-ray photons. We are planning a series of rocket flights to search for sterile neutrinos, a well-motivated dark matter candidate which would decay (with very long lifetimes) into a standard-model neutrino and an X-ray with energy equal to half of the neutrino’s mass. These flights take place from both the White Sands Missile Range in New Mexico and from the Woomera Test Range in Australia.
Searches for Lepton Flavor Violation
Mu2e - M. Schmitt and M. Velasco
Lepton flavor is suppressed in the standard model and occurs only through the phenomenon of neutrino oscillations. We are looking for a forbidden process called “muon conversion” in which a muon that has been captured by an atomic nucleus spontaneously converts to an electron without any neutrinos. This flagship Fermilab experiment should start taking data in 2019.
High Energy Proton-Proton Collisions
CMS at the LHC - K. Hahn, M. Schmitt, and M. Velasco
CMS is a general-purpose experiment that allows us to conduct many different studies of high-energy proton-proton collisions. The collisions are provided by the Large Hadron Collider in Geneva, Switzerland. Hahn and Velasco played important roles in the discovery of the Higgs boson, announced in July 2013. Schmitt is an expert in the physics of W and Z bosons. The CMS group is working on trigger upgrades, luminosity measurement, the forward calorimeter and advanced statistical techniques. Run 2 of the LHC is starting in 2015.
Charm Meson Studies
Jefferson National Laboratory - K. Seth
At the Jefferson Electron Accelerator Laboratory, which has been upgraded to 12 GeV, the group of Prof. Seth is engaged in the design and construction of a new detector, called GlueX, and experiments on photoproduction of light-quark and charm-quark mesons, with special emphasis on the production of the so-called "exotic mesons", the hybrids and glueballs.
The FAIR Accelerator Facility at GSY, Darmstadt - K. Seth
The FAIR accelerator complex is being designed to provide the world's only beams of up to 15 GeV antiprotons, which will be used to study spectroscopy, charmonium, and beyond. Prof. Seth's group is playing a major part in the design of the antiproton beam, and the state-of-the-art detector which will be used for the unique program of proton-antiproton annihilation experiments.
Low-Energy Tests of Fundamental Physics
Low-energy precision measurements place some of the most exacting constraints on extensions to the Standard Model of particle physics. Prof. Gabrielse’s group uses trapped particles and molecular beams to test Quantum Electrodynamics, the CPT theorem, and time-reversal symmetry at the most stringent levels. Prof. Odom’s group is developing methods to trap, cool, and probe trapped molecular ions in order to search for time-variation of the proton-electron mass ratio.