2008/01/25 by Luis A. Sanchez, Luis A. Sánchez, L. A. Wills-Toro +2
Physics and Astronomy · #Dark Matter and Cosmic Phenomena #Electroweak interaction #Gauge (firearms) #Hadron #Large Hadron Collider #Particle physics #Particle physics theoretical and experimental studies #Physics #Physics beyond the Standard Model #Quantum Chromodynamics and Particle Interactions #Quark #Standard Model (mathematical formulation) #hep-ph
paper · pdf · doi:10.1103/physrevd.77.035008
published as Phys.Rev.D77:035008,2008 · 26 pages, 6 tables, 1 figure. Accepted for publication in Phys. Rev. D
arxiv created 2008/01/25 · openalex publication_date 2008/02/25 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
An extension of the gauge group SU(2)L\ensuremath\bigotimesU(1)Y of the standard model to the symmetry group SU(4)L\ensuremath\bigotimesU(1)X (3-4-1 for short) is presented. The model does not contain exotic electric charges and anomaly cancellation is achieved with a family of quarks transforming differently from the other two, thus leading to FCNC. By introducing a discrete Z2 symmetry we obtain a consistent fermion mass spectrum, and avoid unitarity violation of the Cabibbo-Kobayashi-Maskawa mixing matrix arising from the mixing of ordinary and exotic quarks. The neutral currents coupled to all neutral vector bosons are studied, and by using CERN LEP and SLAC Linear Collider data at Z-pole and atomic parity violation data, we bound parameters of the model related to tree-level Z\ensuremath-Z^\ensuremath' mixing. These parameters are further constrained by using experimental input from neutral meson mixing in the analysis of sources of FCNC present in the model. Constraints coming from the contribution of exotic particles to the one-loop oblique electroweak parameters S, T and U are also briefly discussed. Finally, a comparison is done of the predictions of different classes of 3-4-1 models without exotic electric charges.