Volume 79, Number 5, September 2007
Article Number 51001
Number of page(s) 6
Section The Physics of Elementary Particles and Fields
Published online 02 August 2007
EPL, 79 (2007) 51001
DOI: 10.1209/0295-5075/79/51001

Phase structure and phase transitions of the $\mth{SU(2)\times O(N)}$ symmetric scalar field theory

A. Patkós1, 2 and Zs. Szép3

1  Department of Atomic Physics, Eötvös University - H-1117 Budapest, Hungary
2  Research Group for Statistical and Biological Physics of the Hungarian Academy of Sciences H-1117 Budapest, Hungary
3  Research Institute for Solid State Physics and Optics of the Hungarian Academy of Sciences H-1525 Budapest, Hungary

received 18 April 2007; accepted in final form 9 July 2007; published September 2007
published online 2 August 2007

Radiatively induced SU(2) symmetry breaking is shown to be a genuine feature of $SU(2)\times O(N)$ globally symmetric renormalisable field theories in the large-N limit, describing interaction of a complex SU(2) doublet, O(N)-singlet field with an SU(2) singlet, O(N) vector. Symmetry-breaking solutions are found even when all fields have positive renormalised squared mass. The emerging novel mechanism of symmetry breaking can reproduce with a choice of $N\sim 300$ the standard range of the electroweak condensate and the Higgs mass occurring in the extended Higgs dynamics of an SU(2) symmetric Gauge+Higgs model.

11.10.Wx - Finite-temperature field theory.
11.10.Gh - Renormalization.
12.38.Cy - Summation of perturbation theory .

© Europhysics Letters Association 2007