In quest of "just" the Standard Model on D-branes at a singularity

TL;DR

This paper investigates constructing Standard Model-like gauge theories using D3-branes at orbifold singularities with D7-branes, exploring conditions for realistic particle spectra and gauge charge assignments.

Contribution

It proposes a novel setup with D3- and D7-branes at singularities, analyzing conditions for realistic gauge groups and matter content, including hypercharge assignments.

Findings

Standard Model-like spectra are plausible with high N orbifold singularities.

Non-supersymmetric singularities are necessary if no extra charged matter is allowed.

Hypercharge assignments depend on Abelian gauge D7-groups.

Abstract

In this note we explore the possibility of obtaining gauge bosons and fermionic spectrum as close as possible to the Standard Model content, by placing D3-branes at a ZN orbifold-like singularity in the presence of D7-branes. Indeed, we find that this is plausible provided a sufficiently high N is allowed for and the singular point is also fixed by an orientifold action. If extra charged matter is not permitted then the singularity should necessarily be non-supersymmetric. Correct hypercharge assignments require a dependence on some Abelian gauge D7-groups. In achieving such a construction we follow a recent observation made in Ref. [hep-th/0105155] about the possibility that, the three left handed quarks, would present different U(2) transformation properties.