Word: pion
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Dates: during 1960-1969
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Center of the scientific storm is a subatomic particle called the eta meson, which lives for only a billionth of a billionth of a second before breaking down into three smaller particles called pions-one positive, one negative, one without any electrical charge. According to the laws of symmetry, the positive and negative pions should have identical energies. But when a team led by Columbia University's Dr. Paolo Franzini examined 1,441 photographs of eta-meson decay in the Brookhaven bubble chamber (TIME, July 8), they found that in 53% of the photographs the positive pion apparently...
Because the Brookhaven bubble chamber has a fixed magnetic field, the positive pions that Franzini studied always curved in one direction, while the negative pions went the other way. If the field had been uneven for any reason, the higher positive-pion energy levels detected at Brookhaven might well have been erroneous. In the CERN spark chamber, the magnetic field was periodically reversed to make sure that positive and negative pions would both be subject to any variations in the field...
Tunisia's Habib Bourguiba has long been the Arab world's loudest cham pion of women's rights. In 1956, when Tunisia won its independence, Bourguiba abolished polygamy, made it harder for men to get divorces, and gave women their first, real legal rights. He looked on approvingly as the Moslem veil began to vanish, and he has shown no objection to the new garb of girls who parade gracefully through the narrow streets of Tunis in brief, airy frocks. But one has to draw the line somewhere, and last week Bourguiba did-just below the knee...
...antimatter, all particles would be the exact mirror image of their material selves, except that their electrical charges and magnetic poles would be reversed. And it was this that the experiment at Brookhaven called into question. For if it had been done in an antimatter world, the faster positive pion would have been negatively charged. The theoretical symmetry of matter and antimatter would not hold...
...wife, Dr. Juliet Lee-Franzini, Drs. Charles Baltay and Lawrence Kirsch, he fired particles called pi mesons into a bubble chamber filled with liquid deuterium. About one-thirtieth of the times that a pi meson hit a deuterium nucleus, out came the eta meson, which decays into three pions. The pions streaked through the bubble chamber, the positive leaving a line that curved to the right, the negative peeling off to the left, and the neutral leaving no path at all. After analyzing photographs of 1,441 sets of such tracks, the Franzinis determined that in more than half...