Dynamics of Nambu monopole in two Higgs doublet models. Cosmological Monopole Collider
Abstract
We study the dynamics of the Nambu monopole in two Higgs doublet models, which is a magnetic monopole attached by two topological Z strings (Z flux tubes) from two opposite sides. The monopole is a topologically stable solution of the equation of motions when the Higgs potential has global U (1) and &Z;_{2} symmetries. In this paper, we consider more general cases without the &Z;_{2} symmetry, and find that it is no longer a static solution but moves along the Z string being pulled by the heavier string. After analytically constructing an asymptotic form of the monopole, we confirm such a motion using the numerical relaxation method. In addition, we analyze the real time dynamics of the monopole based on a pointlike approximation. Consequently, if there were long string networks with the monopoles in the early universe, the monopole accelerates nearly to the speed of light emitting electromagnetic radiations as a synchrotron accelerator, and collides to an antimonopole on the string. This collision event, which we call the cosmological monopole collider, can produce much heavier particles than those we can see today, e.g., at the Large Hadron Collider.
 Publication:

Journal of High Energy Physics
 Pub Date:
 July 2020
 DOI:
 10.1007/JHEP07(2020)004
 arXiv:
 arXiv:2003.08772
 Bibcode:
 2020JHEP...07..004E
 Keywords:

 Solitons Monopoles and Instantons;
 Beyond Standard Model;
 Higgs Physics;
 High Energy Physics  Phenomenology;
 High Energy Physics  Theory
 EPrint:
 38 pages, 7 figures. v2: minor revisions, new references added