Unity in particle physics: A quest for beauty and simplicity
Abstract
Progress in physics, of a fundamental nature, has often occurred by finding connections between diverse phenomena, in short by realizing a certain unity in diversity. An accompanying quest for beauty and simplicity in the underlying laws of nature, sometimes guided by experiments, and sometimes just by pure thought, has invariably played the dominant role in providing the clue for such a unity.Starting with examples of such a unification, comprising the path-setting contributions of luminaries like Newton, Maxwell, Einstein, and others, the talk will emphasize especially the idea of a unification of all matter: nuclear and non-nuclear, and simultaneously of the three of their fundamental forces: the nuclear, electromagnetic and the weak-radioactive.The far-reaching consequence of such a unity, commonly called “Grand Unification†in shedding light on the elusive properties of the feeblest and the lightest known massive particles – the neutrinos – will be noted. The accompanying possibility of linking the tiny neutrino masses to a resolution of the mystery of the observed matter- antimatter asymmetry of the universe will be presented. Such an asymmetry is, of course, necessary for the origin of life, and thus for our own existence.Perhaps the most profound consequence of grand unification is the prediction that the lightest observed nuclear particle – the proton – which is known to be extraordinarily stable, must ultimately decay entirely into non-nuclear particles such as antielectrons and mesons, albeit with a very long lifetime, as large as some 10^ 35 years. World-wide efforts (in which India is expected to play a major role) to search sensitively for this extraordinary process will be presented. Discovery of proton decay will constitute a landmark in the history of physics.Time permitting, the talk will end by noting briefly the intimate link that exists between the very large (the cosmos), and the very small – the minutest objects of which we are all made
03/11/2014 at 4:00 pm
Prof. Subrata Tripathi, Ex-Professor, TIFR, Mumbai
