TY - JOUR

T1 - Non-Abelian strings and domain walls in two Higgs doublet models

AU - Eto, Minoru

AU - Kurachi, Masafumi

AU - Nitta, Muneto

PY - 2018/8/1

Y1 - 2018/8/1

N2 - Contrary to the standard model that does not admit topologically nontrivial solitons, two Higgs doublet models admit topologically stable vortex strings and domain walls. We numerically confirm the existence of a topological Z-string confining fractional Z-flux inside. We show that topological strings at sin θW = 0 limit reduce to non-Abelian strings which possess non-Abelian moduli S2 associated with spontaneous breakdown of the SU(2) custodial symmetry. We numerically solve the equations of motion for various parameter choices. It is found that a gauging U(1)Y always lowers the tension of the Z-string while it keeps that of the W-string. On the other hand, a deformation of the Higgs potential is either raising or lowering the tensions of the Z-string and W-string. We numerically obtain an effective potential for the non-Abelian moduli S2 for various parameter deformations under the restriction tan β = 1. It is the first time to show that there exists a certain parameter region where the topological W-string can be the most stable topological excitation, contrary to conventional wisdom of electroweak theories. We also obtain numerical solutions of composites of the string and domain walls in a certain condition.

AB - Contrary to the standard model that does not admit topologically nontrivial solitons, two Higgs doublet models admit topologically stable vortex strings and domain walls. We numerically confirm the existence of a topological Z-string confining fractional Z-flux inside. We show that topological strings at sin θW = 0 limit reduce to non-Abelian strings which possess non-Abelian moduli S2 associated with spontaneous breakdown of the SU(2) custodial symmetry. We numerically solve the equations of motion for various parameter choices. It is found that a gauging U(1)Y always lowers the tension of the Z-string while it keeps that of the W-string. On the other hand, a deformation of the Higgs potential is either raising or lowering the tensions of the Z-string and W-string. We numerically obtain an effective potential for the non-Abelian moduli S2 for various parameter deformations under the restriction tan β = 1. It is the first time to show that there exists a certain parameter region where the topological W-string can be the most stable topological excitation, contrary to conventional wisdom of electroweak theories. We also obtain numerical solutions of composites of the string and domain walls in a certain condition.

KW - Beyond Standard Model

KW - Solitons Monopoles and Instantons

UR - http://www.scopus.com/inward/record.url?scp=85052696324&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85052696324&partnerID=8YFLogxK

U2 - 10.1007/JHEP08(2018)195

DO - 10.1007/JHEP08(2018)195

M3 - Article

AN - SCOPUS:85052696324

VL - 2018

JO - Journal of High Energy Physics

JF - Journal of High Energy Physics

SN - 1126-6708

IS - 8

M1 - 195

ER -