Eur. Phys. J. C (2013) 73: 2577
https://doi.org/10.1140/epjc/s10052-013-2577-5

Regular Article - Theoretical Physics

The vector resonance triplet with the direct coupling to the third quark generation

¹ Physics Department, University of Žilina, Univerzitná 1, 010 26, Žilina, Slovakia
² Institute of Experimental and Applied Physics, Czech Technical University in Prague, Horská 3a/22, 128 00, Prague, Czech Republic
³ Institute of Physics, Silesian University in Opava, Bezručovo nám. 13, 746 01, Opava, Czech Republic

^* e-mail: josef.juran@utef.cvut.cz

Received: 8 July 2013
Revised: 25 August 2013
Published online: 1 October 2013

Abstract

The effective Lagrangian with scalar and vector resonances that might result from new strong physics beyond the SM is formulated and studied. In particular, the scalar resonance representing the recently discovered 125-GeV boson is complemented with the SU(2) _L+R triplet of hypothetical vector resonances. Motivated by experimental and theoretical considerations, the vector resonance is allowed to couple directly to the third quark generation only. The coupling is chiral-dependent and the interaction of the right top quark can differ from that of the right bottom quark. To estimate the applicability range of the effective Lagrangian the unitarity of the gauge boson scattering amplitudes is analyzed. The experimental fits and limits on the free parameters of the vector resonance triplet are investigated.