Nuclear Physics (1986) / Chapter Skim
Currently Skimming:
9 The Electroweak Synthesis and Beyond
9 The Electroweak Synthesis and Beyond
Pages 160-168
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 160... ...
Glashow led to a remarkable synthesis of electromagnetism and the weak nuclear force into a single electroweak force. This achievement, one of the triumphs of modern science, has had a profound effect on the development of nuclear physics and particle physics during the last decade.
|
From page 161... ...
As for the conservation laws for certain other properties, such as lepton family number, we do not know whether an underlying symmetry principle is at work or whether the law seems to hold only because present experiments are insufficiently sensitive to detect possible violations of it. The mathematical form of the electroweak theory inspires confidence, however, because it is the only known theory of the weak interaction that is renormalizable.
|
From page 162... ...
Such experiments permit the study of the weak part of the electroweak force and, by comparison with the much more easily studied electromagnetic part, can test the fundamental unity of the electroweak interaction. An experiment now under way at the Los Alamos National Laboratory is designed to measure the scattering of electron neutrinos from electrons in an advanced detector.
|
From page 163... ...
energies; the catch is that at cosmological energies, such as must have existed briefly after the big bang, they predict a bewildering variety of phenomena that are as bizarre as they are different. These differences between contending Grand Unified Theories become evident only at particle energies estimated to be about 1O'5 GeV, which is hopelessly beyond the reach of any currently conceivable terrestrial accelerator and far above even the energies of cosmic rays.
|
From page 164... ...
Now that tentative Grand Unified Theories are available, it appears to be possible to incorporate time-reversal-invariance violation into their framework, based on certain details of the decay properties of these kaons. Experiments to measure the neutral kaon decay precisely and to search for evidence of time-reversal-invariance violation in another possible decay mode may be crucial in finding the correct way to account for the violation in the context of grand unification.
|
From page 165... ...
If the neutron has an electric dipole moment, the energy added by the electric interaction will slightly shift the difference between the neutron's energy levels in the magnetic field. Current experiments are sensitive to shifts as small as 0.001 hertz.
|
From page 166... ...
Intensive effort at all three of the world's meson factories the Los Alamos Meson Physics Facility, the Tri-University Meson Facility (Vancouver, British Columbia) , and the Swiss Institute of Nuclear Research (Villigen)
|
From page 167... ...
(Courtesy of the Los Alamos National Laboratory.)
|
From page 168... ...
In addition to high experimental selectivity and sensitivity, this search requires the maximum possible beam intensities, in order to produce the huge numbers of events among which the occasional rare ones may be found. These invaluable bits of information from nuclear physics may ultimately prove essential for weaving together our fragmentary knowledge into a Grand Unified Theory of the fundamental interactions.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.