Fermilab produced its first high-energy particle beam on March 1, 1972. Since then hundreds of experiments have used Fermilab’s accelerators to study matter at ever smaller scales. Here an overview of the top ten achievements so far.

Discovery of the top quark
On March 2, 1995, physicists at Fermilab’s CDF and DZero experiments announced the discovery of the top quark, the last undiscovered quark of the six predicted to exist by current scientific theory. Scientists worldwide had sought the top quark since the discovery of the bottom quark at Fermilab in 1977. Physicists discovered the top, as heavy as an entire gold atom but much smaller than a single proton, using particle beams from the Tevatron, the world’s highest energy particle accelerator.

Discovery of the bottom quark and subsequent studies of its properties
Physicists at Fermilab’s E288 collaboration, led by Nobel laureate Leon Lederman, announced the discovery of a new particle named the upsilon on June 30, 1977. The experimenters showed that the upsilon particle contains a bottom quark and an anti-bottom quark: Thus, the third generation of quarks was revealed.

Determination of top quark and W boson masses to high precision
Particle physicists measure particle masses to verify the correctness and accuracy of their  particle models. Knowing the value of the top quark mass to high precision has allowed  physicists to zero in on the mass of the undiscovered Higgs boson, a crucial component of  the theoretical framework of particle physics.

Observation of direct CP violation in kaon decays
On February 24, 1999, physicists from Fermilab’s KTeV collaboration announced results
establishing the existence of direct CP violation in the decay of kaons (particles containing a strange quark). The observation is a significant step in understanding why the universe displays an abundance of matter, while antimatter disappeared at an early stage in the evolution of the universe.

Precise measurement of the lifetimes of charm particles
The charm quark, the fourth quark of the Standard Model, is much heavier than the first  three quarks. Studying the production and decay mechanisms of charm particles when produced in proton-antiproton collisions proved to be crucial in understanding the forces between quarks and how quarks combine to form composite particles.

First direct evidence for the tau neutrino
On July 21, 2000, scientists at Fermilab announced the first direct evidence for the tau neutrino, the third kind of neutrino known to particle physicists. Although earlier experiments had produced convincing indirect evidence for the particle’s existence, no one had directly observed the interaction of a tau neutrino with matter. Tau neutrinos are massless or almost massless particles that carry no electric charge and barely interact with surrounding matter, making an observation extremely difficult. With the tau neutrino observation, three of the four particles of the third generation of the Standard Model were discovered at Fermilab: the bottom quark, the top quark and then the tau neutrino.

Mapping the structure of protons and neutrons using neutrino beams
Using neutrino beams has proved a unique and fruitful method of studying the structure of matter at the smallest scales possible. Since neutrinos have no electric charge, they can probe quarks, the building blocks of protons and neutrons, via weak interactions, complementing decades of studies based on electromagnetic interactions. A long series of experiments at Fermilab and other high-energy laboratories has carefully mapped the composition of protons, antiprotons and neutrons. Measurement of the magnetic moments of particles containing strange quarks Hyperons, subatomic relatives of the proton, are like tiny magnets that live less than a billionth of a second. From 1975 to 1985, precision experiments at Fermilab measured their magnetic strengths and clearly showed that hyperons are made of quarks, a major contribution to formulating the theoretical framework called the Standard Model.

Discovery of a quasar at a distance of 27 billion light years
On April 13, 2000, scientists of the Sloan Digital Sky Survey announced the observation of the most distant object ever observed, a quasar at a red shift of 5.8, a distance of 27 billion light years from Earth. The SDSS collaboration will ultimately survey 10,000 square degrees, or one quarter of the sky, and 200 million celestial objects. Fermilab scientists are involved in managing and analyzing this large amount of data. These astrophysical studies complement Fermilab’s quest to understand the structure and evolution of the universe.

Calculation of the strong coupling constant using supercomputers
Quarks interact via the strong force. Many properties of this short-range force are  calculable only with the aid of the large-scale numerical calculations of lattice gauge theory. Using powerful supercomputers, the Fermilab lattice gauge theory group performed the first accurate determination of the “strong coupling constant,” the characteristic strength describing this force. The calculation presented one of the first accurate lattice determinations of any fundamental parameter of the standard model.

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Discovery of tiny nerves from rib cage when mixed with a powerful growth inducer found in most nerve cells could significantly reverse spinal cord injury incurred paralysis according to the results found in a study at UC Irvine and Long Beach Veterans Administration Medical Center.

It was found out from the study conducted in rats that nerve cells can be inserted and stimulated to grow through damaged areas of the spinal cord and could perhaps lead to better treatment for spinal cord injuries thereby challenging the common knowledge that severed spinal cord nerves are almost impossible to regenerate.

The Spinal Cord Injury Group directed by Dr. Vernon Lin, professor of Physical Medicine at UCI at the Long Beach Veterans Administration discovered that grafting nerves from the rib cage and adding the growth stimulator called aFGF partially restored the hind leg movement in rats that had severed spinal cords.

This finding is very significant because the study gets us closer to arriving the right combination of growth factors, nerve cells and physical stimulation to overcome inhibitions of growth of new nerve-cell connections resulting to difficulties in severed spinal cord nerve-regeneration.

By using tiny nerves from the rib cage as cables connecting the severed spinal cord, Lin and his team were able to get some improvement in leg function of the 12 rats with severed spinal cords and were able to move their hind legs again after treatment with both the aFGF and the nerve grafts, while rats that had either the aFGF or nerve grafts alone showed nearly no improvement. Rats receiving both the growth factor and the nerve cell grafts could support some of their weight on their back legs.

The growth factor aFGF is normally produced in the spinal cord by nerve cells, but scientists suspect that it is stored and only used when nerve cells are damaged. Previous studies have shown that adding aFGF can stimulate growth in individual nerve cells in the laboratory.

The rats’ movements were measured using a tool called a BBB score. Normal movement rates a BBB score of about 21. Six months after the rats were treated, the animals that received the aFGF and nerve grafts had scores between six and seven. The other animals did not score higher than one on the scale.

“While not a perfectly normal score of locomotion, the treatments did allow the rats to step forward and put weight on their hind legs,” Lin said. “We also found that the nerves in the leg below the injury site were once again receiving nerve impulses from the brain. We believe that eventually, we may be able to find the right mix of factors and physical stimulation all working together to improve this restored movement to more normal levels.”

The researchers also plan to study the use of robots to aid in the placement and maintenance of nerve cells that are grafted into an injured area, to help improve movement. They recently received a $600,000 research grant from the Veterans Administration to continue their work in designing and testing robots that could help in maintaining the gait necessary to walk. Currently, they are testing the ability of the robots to accurately maintain a walking gait in rats. Eventually, the researchers hope to test the robots in humans and determine if the machines are actually helping restore the ability to walk after spinal cord injury.

The study appears in the October issue of the Journal of Neurotrauma.

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A research team that involves a professor of Kent State University had recently discovered a promising new type of liquid crystal that could lead to faster and lower priced liquid crystal display.

This new liquid crystal form called the biaxial nematic liquid crystal could revolutionize the display technology because it will make the liquid crystal display capability more than 10 times faster allowing cost-saving measures as compared to the current liquid crystal displays used in most laptops and televisions today which make use of the uniaxial nematic liquid crystal technology.

Thirty four years ago, IBM’s Thomas J. Watson Research Center in Yorktown Heights, New York predicted the existence of the biaxial nematic liquid crystal however no evidence of the existence of biaxial nematic liquid crystals made of single molecules had ever been found until today although other types of more complex micellar biaxial liquid crystals were found previously by researchers at Kent State but none had the exact optical properties necessary in the manufacture of displays and photonics devices.

Small-angle x-ray diffraction method had been employed by the researchers to discover the biaxial nematic liquid crystal and report of this undertaking appeared in the April 9 issue of the prestigious Physical Reviews Letters.

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