Proton Decay in Intersecting D-brane Models

TL;DR

This paper investigates proton decay rates in specific string-inspired GUT models, finding that despite amplitude enhancements, the predicted proton lifetime remains around 10^36 years, consistent with current experimental bounds.

Contribution

It provides a detailed analysis of proton decay via dimension six operators in intersecting D-brane models, highlighting the impact of amplitude enhancement factors.

Findings

Proton decay amplitude is enhanced by a factor of α_GUT^(-1/3).

Predicted proton lifetime remains near 10^36 years.

Enhancement effects do not significantly alter decay rate predictions.

Abstract

We analyze proton decay via dimension six operators in certain GUT-like models derived from Type IIA orientifolds with $D6$-branes. The amplitude is parametrically enhanced by a factor of $\alpha_{GUT}^{-1/3}$ relative to the coresponding result in four-dimensional GUT's. Nonetheless, even assuming a plausible enhancement from the threshold corrections, we find little overall enhancement of the proton decay rate from dimension six operators, so that the predicted lifetime from this mechanism remains close to $10^{36}$ years.