Abstract
Theoretical predictions for the proton’s lifetime, τp in grand unified theories are reviewed. A simple procedure for computing MS, the super-heavy mass of the vector bosons which mediate proton decay in the Georgi-Glashow SU(5) model, is outlined. Using the current value of αS the QCD coupling, obtained from electroproduction as input, the SU(5) model is found to predict MS=8.5×1014 GeV, sin 2ϴW=0.207 and τp≃1−20×1031 yr.
Work supported in part by the U.S. Department of Energy under Contract Grant No. EY-76-C-02-2232B.*000.
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References
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In addition to poles, I also subtract extraneous contributions such as Euler’s constant y and √4π which arise in dimensional regularization. That is why I use the QCD parameter MS extracted from experiment.
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The predictions for τp in eqs. (12) and (13) along with the values quoted in Table I were obtained using amplitude enhancement factors appropriate for αS(MW)=0.14. For values of αS(MW) smaller than 0.14, the proton lifetime τp is actually smaller than the results I have given, because the enhancement factors should be increased; the opposite effect occurs for αS(MW)>0.14.
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Marciano, W.J. (1980). Theoretical Aspects of Proton Decay. In: Perlmutter, A., Scott, L.F. (eds) Recent Developments in High-Energy Physics. Springer, Boston, MA. https://doi.org/10.1007/978-1-4613-3165-0_10
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