Heterotic Non-Abelian String of a Finite Length
| Autor: | Monin, S., Shifman, M., Yung, A. |
|---|---|
| Rok vydání: | 2016 |
| Předmět: | |
| Zdroj: | Phys. Rev. D 93, 125020 (2016) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevD.93.125020 |
| Popis: | We consider non-Abelian strings in N=2 supersymmetric QCD with the U$(N)$ gauge group and $N_f=N$ quark flavors deformed by a mass term for the adjoint matter. This deformation breaks N=2 supersymmetry down to N=1. Dynamics of orientational zero modes on the string world sheet are described then by CP$(N-1)$ model with N=(0,2) supersymmetry. We study the string of a finite length $L$ assuming compactification on a cylinder (periodic boundary conditions). The world-sheet theory is solved in the large-$N$ approximation. We find a rich phase structure in the $(L, \,u)$ plane where $u$ is a deformation parameter. At large $L$ and intermediate $u$ we find a phase with broken $Z_{2N}$ symmetry, $N$ vacua and a mass gap. At large values of $L$ and $u$ still larger we have the $Z_{2N}$-symmetric phase with a single vacuum and massless fermions. In both phases N=(0,2) supersymmetry is spontaneously broken. We also observe a phase with broken SU$(N)\;$ symmetry at small $L$. In the latter phase the mass gap vanishes and the vacuum energy is zero in the leading $1/N$ approximation. However, we expect that $1/N$ corrections will break N=(0,2) supersymmetry. We also discuss how this rich phase structure matches the N=(2,2) limit in which the world-sheet theory has a single phase with the mass gap independent of $L$. Comment: 31 pages, 9 figures |
| Databáze: | arXiv |
| Externí odkaz: |
|