Coupling Selection Rules in Heterotic Calabi-Yau Compactifications

Abstract

We study coupling selection rules of chiral matter fields in heterotic string theory with standard embedding. These selection rules are determined by topological properties of Calabi-Yau threefolds. We classify coupling selection rules on complete intersection Calabi-Yau threefolds for $h^{1,1}\le 5$. It is found that all of these selection rules for $h^{1,1}\le 5$ are understood by combinations of only five types of fusion rules.

v2: 31 pages, published version