For Fermilab, 2011 promises to be an interesting year on many fronts. The Tevatron particle collider performed exceptionally well in 2010, and scientists of the CDF and DZero collaborations are now sifting through the wealth of proton-antiproton collision data and plan to show their latest findings at the European winter conferences in March. Both groups are looking for signs of the elusive Higgs particle and hints for physics beyond the Standard Model. The CDF collaboration already jumped the gun: on Friday, CDF scientists showed new data that reinforce the possibility for a new type of asymmetry in the production of top quarks, first reported in 2006 and 2008.
Fermilab's Tevatron is four miles in circumference. The machine makes protons and antiprotons collide at close to light speed. Credit: Fermilab
This is not the only hint of new physics the Tevatron has created in the last couple of years and that physicists will try to confirm or refute. Last summer, the DZero collaboration reported surprising signs for a new type of matter-antimatter asymmetry involving bottom quarks, but the data were not sufficient to claim a discovery. It remains to be seen whether DZero scientists will have more to say about this mystery at the winter conferences. One thing is clear: the Standard Model of particles and their forces does not explain the dominance of matter over antimatter in our universe. There must exist some subatomic mechanism beyond the ones discovered so far–but so far it eludes detection.
The most anticipated results at the winter conferences might be the updates on the Higgs searches at the CDF and DZero experiments and results from the Large Hadron Collider experiments. The Tevatron experiments will either expand their Higgs mass exclusion range—currently ranging from 158 to 175 GeV/c2—or, if the actual mass of the Higgs particle is barely outside this range, their experimental data will begin to deviate from the no-Higgs computer simulations. Although the Tevatron will shut down at the end of September, its data analysis will continue for years.
Physicists at Fermilab also hope to continue their streak of surprising neutrino results. Last summer, the MINOS and MiniBooNE experiments created headlines with data that suggested that neutrinos and antineutrinos behave differently—a no-no in the Standard Model. The two experiments are busy collecting additional data and eager to shed more light on the always-surprising properties of the neutrino. A third neutrino experiment, Minerva, whose construction was completed last year, will have results in the near future as well.
In 2010, construction workers finished the exterior of this new neutrino research building in northern Minnesota. Technicians will begin the installation of the 14,000-kiloton NOvA neutrino detector in the second half of 2011. Credit: Dan Traska, Einarson Air
Then there is the construction of the 14,000-ton NOvA neutrino detector, which scientists will use to look for neutrino oscillations. Last fall, construction crews finished the excavation of an approximately 100-meter-long and 20-meter-wide hole in Ash River, Minnesota, and began to construct the building that will hold this enormous neutrino detector. A small prototype detector at Fermilab recorded its first neutrino interaction in December, and the NOvA collaboration will carry out the mass production of the components for the large detector this year. The exterior of the new building in Minnesota is complete, and technicians will begin the installation of the NOvA detector in the second half of 2011. Two other proposed neutrino experiments at Fermilab, MicroBooNE and the Long-Baseline Neutrino Experiment, are in their planning phases.
The particle astrophysicists at Fermilab plan to start up several new experiments this year. This spring, the Dark Energy Survey will ship components of a 570-megapixel Dark Energy Camera to Chile, for installation on the Blanco telescope. (See this time-lapse video of the camera’s construction at Fermilab.) When complete, scientists will use the super-sensitive camera to survey a significant portion of the southern night sky, recording the faint light emitted by galaxies when the universe was only a few billion years old. The data will allow scientists to check whether the dark-energy force or deviations in the theory of gravity can explain why the expansion of the universe is speeding up. On Tuesday, Jan. 11, DES scientists will present their plans at a special session at the AAS conference in Seattle.
The COUPP collaboration has built a new particle detector, shown here under construction at Fermilab about a year ago, to search for dark-matter particles 2,000 meters underground in a mine in Canada, home of SNOLAB. Credit: Fermilab
The search for dark-matter particles will heat up in 2011 as the CDMS collaboration is increasing the size of its ultrasensitive, ultracold dark-matter detector, located almost a kilometer underground in the Soudan mine in Minnesota, while the COUPP collaboration is moving its bubble-chamber-style dark-matter detectors from Fermilab to Canada. Using better and larger detectors, COUPP scientists will look for the tell-tale signs of weakly interacting massive particles, or WIMPs, more than 2,000 meters underground at SNOLAB. Several groups, including CDMS, reported candidates for dark-matter particles in the last two years, and both CDMS are COUPP are eager to put their more sensitive detectors to work. The deeper location at SNOLAB will shield the COUPP detectors more effectively from cosmic rays than the 100-meter-deep underground hall at Fermilab.
2011 might also tell us more about the possibility of a holographic universe. A team of Fermilab physicists are advancing plans for a Holometer, a laser-based experiment that would look for tiny spacetime vibrations to check whether our reality is an illusion. The experiment would deliver the most sensitive measurement every made of spacetime.
In 2011, Fermilab also hopes to receive first-stage approval from the U.S. Department of Energy for Project X, a user facility with a half-mile-long, high-intensity proton accelerator that would provide beam to a set of muon, kaon and nuclear experiments. It also would be the first large-scale application of high-gradient superconducting radio-frequency cavities in the United States, a technology that scientists hope to use for future particle colliders as well. Last week, the Chronicle of Higher Education published an in-depth article on Fermilab’s transition from the Tevatron collider to the Project X accelerator and its experiments.
It will be an interesting year at Fermilab. Stay tuned.
Kurt Riesselmann
Fermilab Office of Communication
