TY - JOUR

T1 - Topological Nambu monopole in two Higgs doublet models

AU - Eto, Minoru

AU - Hamada, Yu

AU - Kurachi, Masafumi

AU - Nitta, Muneto

N1 - Funding Information:
We would like to thank Nobuyuki Matsumoto for useful discussions. This work is supported by the Ministry of Education, Culture, Sports, Science ( MEXT ) – Supported Program for the Strategic Research Foundation at Private Universities “Topological Science” (Grant No. S1511006 ). The work is also supported in part by JSPS Grant-in-Aid for Scientific Research (KAKENHI Grant No. JP16H03984 (M. E. and M. N.), No. JP19K03839 (M. E.), No. JP18J22733 (Y. H.), No. JP18K03655 (M. K.), No. JP18H01217 (M. N.)), and also by MEXT KAKENHI Grant-in-Aid for Scientific Research on Innovative Areas “Topological Materials Science” No. JP15H05855 (M. N.) and “Discrete Geometric Analysis for Materials Design” No. JP17H06462 (M. E.) from the MEXT of Japan.
Publisher Copyright:
© 2020 The Author(s)

PY - 2020/3/10

Y1 - 2020/3/10

N2 - We show that a topological Nambu monopole exists as a regular solution for a large range of parameters in two Higgs doublet models, contrary to the standard model admitting only non-topological Nambu monopoles. We analyze a Higgs potential with a global U(1) symmetry and a discrete symmetry Z2. The monopole is attached by two topological Z strings (Z flux tubes) from both sides. Despite of a trivial second homotopy group, the discrete symmetry Z2 together with a non-trivial first homotopy group for Z strings topologically ensures the topological stability. After analytically constructing an asymptotic form of such a configuration, we explicitly construct a solution of the equation of motion based on a 3D numerical simulation, in which magnetic fluxes spherically emanating from the monopole at large distances are deformed in the vicinity of the monopole. Since the monopoles are expected to be abundant in the present universe, they might be observed in the current monopole searches.

AB - We show that a topological Nambu monopole exists as a regular solution for a large range of parameters in two Higgs doublet models, contrary to the standard model admitting only non-topological Nambu monopoles. We analyze a Higgs potential with a global U(1) symmetry and a discrete symmetry Z2. The monopole is attached by two topological Z strings (Z flux tubes) from both sides. Despite of a trivial second homotopy group, the discrete symmetry Z2 together with a non-trivial first homotopy group for Z strings topologically ensures the topological stability. After analytically constructing an asymptotic form of such a configuration, we explicitly construct a solution of the equation of motion based on a 3D numerical simulation, in which magnetic fluxes spherically emanating from the monopole at large distances are deformed in the vicinity of the monopole. Since the monopoles are expected to be abundant in the present universe, they might be observed in the current monopole searches.

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U2 - 10.1016/j.physletb.2020.135220

DO - 10.1016/j.physletb.2020.135220

M3 - Article

AN - SCOPUS:85078627897

SN - 0370-2693

VL - 802

JO - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics

JF - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics

M1 - 135220

ER -