Nonlocal SU(5) GUT

TL;DR

This paper proposes a nonlocal extension of the SU(5) GUT that addresses proton lifetime and Weinberg angle issues without extra particles, linking the nonlocal scale to the GUT scale.

Contribution

It introduces a nonlocal modification to the SU(5) GUT that naturally solves key problems and relates the nonlocal scale to the GUT scale, including the Planck scale.

Findings

Nonlocal SU(5) GUT can solve proton lifetime problems.

The nonlocal scale coincides with the GUT scale.

The GUT scale can be arbitrarily high, up to the Planck scale.

Abstract

We show that in nonlocal generalization of standard nonsupersymmetric SU(5) GUT it is possible to solve the problems with the proton lifetime and the Weinberg angle without introduction of additional particles in the spectrum of the theory. Non-local scale responsible for ultraviolet cutoff coincides (up to some factor) with GUT scale. We find that in the simplest nonlocal modification of the SU(5) model $M_{\rm GUT} = 3 * 10^{16}$ GeV . In general case the value of M_GUT is an arbitrary and the most interesting option $M_{\rm GUT} = O(M_{\rm PL})$ could be realized.