Reconciling grand unification with strings by anisotropic compactifications
- Department of Physics, Ohio State University, 191 West Woodruff Avenue, Columbus, Ohio 43210 (United States)
We analyze gauge coupling unification in the context of heterotic strings on anisotropic orbifolds. This construction is very much analogous to effective five-dimensional orbifold grand unified theory field theories. Our analysis assumes three fundamental scales: the string scale M{sub S}, a compactification scale M{sub C}, and a mass scale for some of the vectorlike exotics M{sub EX}; the other exotics are assumed to get mass at M{sub S}. In the particular models analyzed, we show that gauge coupling unification is not possible with M{sub EX}=M{sub C}, and in fact we require M{sub EX}<<M{sub C}{approx}3x10{sup 16} GeV. We find that about 10% of the parameter space has a proton lifetime (from dimension six gauge exchange) 10{sup 33} yr < or approx. {tau}(p{yields}{pi}{sup 0}e{sup +})< or approx. 10{sup 36} yr. The other 80% of the parameter space gives proton lifetimes below Super-Kamiokande bounds. The next generation of proton decay experiments should be sensitive to the remaining parameter space.
- OSTI ID:
- 21254208
- Journal Information:
- Physical Review. D, Particles Fields, Vol. 78, Issue 6; Other Information: DOI: 10.1103/PhysRevD.78.066006; (c) 2008 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2821
- Country of Publication:
- United States
- Language:
- English
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