Yukawa Couplings involving Excited Twisted Sector States for ${\bf Z}_N$ and ${\bf Z}_M\times {\bf Z}_N$ Orbifolds

TL;DR

This paper investigates the structure of Yukawa couplings involving excited twisted states in heterotic string compactifications on specific orbifolds, providing insights into their role in low-energy effective theories.

Contribution

It presents a detailed analysis of Yukawa couplings for excited twist fields in heterotic orbifold models, a topic not extensively explored before.

Findings

Derived explicit forms of Yukawa couplings involving excited twist states.

Identified conditions under which these couplings are non-zero.

Enhanced understanding of the low-energy phenomenology of heterotic orbifolds.

Abstract

We study the Yukawa couplings among excited twist fields which might arise in the low-energy effective field theory obtained by compactifying the heterotic string on ${\bf Z}_N$ and ${\bf Z}_M\times {\bf Z}_N$ orbifolds.