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Scientific Achievements and Contributions
1962–1969 | 1970–1979 | 1980–1989 | 1990–1999 | 2000–-
2000–-- 2005: Deciphering the Archimedes Palimpsest
- Scientists at SSRL are employing modern technology, including x-ray fluorescence, to completely read the Archimedes Palimpsest, the only source for at least two
previously unknown treatises thought out by Archimedes in the 3rd century B.C. A synchrotron x-ray beam has been used to illuminate the obscured work—erased, written over
and even painted over in the centuries since its initial creation.
- 2004: First SPEAR3 Beam into SSRL Beam Line Hutch
- 2003:
BaBar Identifies New Subatomic Particle
- The new particle called the Ds (2317), which combines a charm quark with another heavy quark—an anti strange, has unexpected properties that will provide insight into
the force that binds the quarks together. This force, unlike most others in nature, becomes stronger as the distance between the two quarks increases.
- 2001:
BaBar Physicists Find a Striking Difference Between Matter and Antimatter
- Physicists from the BaBar experiment directly detected charge-parity violation for the first time in 2001. CP violation is thought to explain why the universe is
composed entirely of matter, even though equal amounts of matter and antimatter should have been created in the Big Bang. The result determines directly for the first time
the magnitude of the fundamental matter-antimatter asymmetry.
1990-1999
- 1990s: Experimentation at SLD Reveals Z Boson Preference
- The SLD is collecting data on the production of the Z0 boson using a polarized electron beam. This will lead to the most precise measurement of a crucial parameter in
particle physics theory as well as unique measurements on B-mesons. Recent running with the SLD has confirmed a predicted small preference for producing the Z0 boson when
the beam is polarized with the spins rotating about the beam axis in a left-handed sense. This distinction between left- and right-handedness at the fundamental particle
level is one of the most intriguing phenomena in subatomic physics.
- 1991: SLAC Ignites World Wide Web
- The first website in North America is up and running at SLAC in 1991 revealing the potential of the web to particle physicists and the greater community.
1980-1989
- 1989: SLC Measures the Limit of Three Quark Generations
- Completed in 1989, the Stanford Linear Collider (SLC) has been instrumental to particle physics theory. Results gathered in 1989 and 1990 showed that there are only
three kinds of neutrinos with a mass less than 1/2 of the Z meson leading to the suggestion that the universe is in fact made up of not more than the three known families
of elementary particles, each with two kinds of leptons and two kinds of quarks.
- 1980-1982: PEP Measures B Meson Lifetime
- Operational in 1980, the PEP tunnel, 800 meters in diameter, became home to electron-positron collisions with center-of-mass energies of up to 30 GeV. Measuring the
lifetimes of elementary particles, PEP experiments were designed to study how quarks are initially produced in collisions, fragmenting or evolving into various kinds of
particles observed in the detection apparatus. In addition PEP has been used to test the theory of Quantum Chromodynamics or QCD, presently believed to describe the strong
force that binds quarks together. It was at PEP between 1980–1982 that experimentation revealed the B quark to have a much longer lifetime than previously anticipated.
1970-1979
- 1975: The Homebrew Computer Club begins meeting in the SLAC auditorium (1975)
- The seminal catalyst of the personal computer revolution ignited the cultural and technological renaissance which transferred computing from corporate/ government hands
to the individual.
- 1975: Discovery of the Tau Lepton at SPEAR
- In 1975, using experimental data from 1973–1974, Martin Perl discovered that sometimes when an electron and positron annihilate one another, the detector records only
one electron-type track and one muon-type track. These events were noted at rates that could only be explained by postulating a new particle type, one just like the
electron only 3,000 times more massive. The resulting discovery of the Tau lepton earned Martin Perl the Nobel Prize in Physics in 1995 for his instrumental contribution to
lepton physics.
- 1973-1974: Charm Discovered at SPEAR
- Leading the group that designed and built the Stanford Positron Electron Asymmetric Ring, Burton Richter (SLAC) conducted a series of experiments from 1973–1974 to study
the rate of occurrence of events in which a colliding electron and a positron annihilate, disappearing and producing other particles in the process. At certain energies the
rate of annihilation seemed inexplicably large. On November 10, 1974, re-measurements in the problematic energy range confirmed a dramatic rate increase whose cause was due
to the production of particles containing a new kind of quark, the charm quark. For their work towards the discovery of a new heavy elementary particle, Burton Richter and
Samuel Ting (Brookhaven) received the Nobel Prize in Physics in 1976.
- 1973: SSRL Begins X-ray Imaging
- In 1973, SSRL opens as the first laboratory in the world to use synchrotron produced x-rays.
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1962-1969
- 1966-1978: Discovery of the Quark
- From 1966–1978, Richard Taylor (SLAC), Henry Kendall (MIT) and Jerome Friedman (MIT) conducted experiments to study how high-energy electrons bounce off protons and
neutrons in a target. Their results indicated that there were more electrons bouncing back with high energy at large angles than could be explained if protons and neutrons
were uniform spheres of matter. The experiments they conducted came to reveal the extremely small, dense objects moving around within the protons and neutrons known as
quarks. For their pioneering work in the development of the quark model of particle physics, these scientists shared the Nobel Prize in Physics in 1990.
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