Higher Winding Strings and Confined Monopoles in N=2 SQCD

TL;DR

This paper investigates complex string and monopole configurations in N=2 SQCD, revealing new composite confined monopoles with higher magnetic flux and analyzing their quantum properties and RG flow.

Contribution

It introduces the existence of higher winding strings and composite monopoles in N=2 SQCD and analyzes their properties using the Hanany--Tong model.

Findings

Identified three distinct 2-string vacua and BPS kinks between them.

Discovered a composite bimonopole with twice the magnetic flux and mass.

Analyzed quantum effects and RG flow in the model.

Abstract

We consider composite string solutions in N=2 SQCD with the gauge group U(N), the Fayet--Iliopoulos term \xi \neq 0 and N (s)quark flavors. These bulk theories support non-Abelian strings and confined monopoles identified with kinks in the two-dimensional world-sheet theory. Similar and more complicated kinks (corresponding to composite confined monopoles) must exist in the world-sheet theories on composite strings. In a bid to detect them we analyze the Hanany--Tong (HT) model, focusing on a particular example of N=2. Unequal quark mass terms in the bulk theory result in the twisted masses in the N=(2,2) HT model. For spatially coinciding 2-strings, we find three distinct minima of potential energy, corresponding to three different 2-strings. Then we find BPS-saturated kinks interpolating between each pair of vacua. Two kinks can be called elementary. They emanate one unit of the magnetic flux and have the same mass as the conventional 't Hooft--Polyakov monopole on the Coulomb branch of the bulk theory (\xi =0). The third kink represents a composite bimonopole, with twice the minimal magnetic flux. Its mass is twice the mass of the elementary confined monopole. We find instantons in the HT model, and discuss quantum effects in composite strings at strong coupling. In addition, we study the renormalization group flow in this model.