Stringy Unification Helps See - Saw Mechanism
نویسندگان
چکیده
In this paper we explore the possibility of intermediate scale physics in the context of superstring models with higher Kac-Moody levels, by focusing on leftright and Pati-Salam symmetries. We find that the left-right scale may lie in the range 10 − 10 GeV which is favored by neutrino physics, while the Pati-Salam scale is at most two or three orders of magnitude below the unification scale MX . We also show that the scale of B−L breaking can be as low as 1 TeV or so, providing protection against too rapid proton decay in supersymmetry. Our results allow a natural value for the scale MX ∼ 10 GeV and the agreement with the experiment requires the value of sin θw at MX to be in general very different from the usually assumed 3/8. ∗ e-mail: [email protected] † e-mail: [email protected]
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