Discovery and identification ofW′andZ′inSU(2)1⊗SU(2)2⊗U(1)Xmodels at the LHC

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We explore the discovery potential of ${W}^{\ensuremath{'}}$ and ${Z}^{\ensuremath{'}}$ boson searches for various $SU(2{)}_{1}\ensuremath{\bigotimes}SU(2{)}_{2}\ensuremath{\bigotimes}U(1{)}_{X}$ models at the Large Hadron Collider (LHC), after taking into account the constraints from low energy precision measurements and direct searches at both the Tevatron (1.96 TeV) and the LHC (7 TeV). In such models, the ${W}^{\ensuremath{'}}$ and ${Z}^{\ensuremath{'}}$ bosons emerge after the electroweak symmetry is spontaneously broken. Two patterns of the symmetry breaking are considered in this work: one is $SU(2{)}_{L}\ensuremath{\bigotimes}SU(2{)}_{2}\ensuremath{\bigotimes}U(1{)}_{X}\ensuremath{\rightarrow}SU(2{)}_{L}\ensuremath{\bigotimes}U(1{)}_{Y}$ (breaking pattern I), another is $SU(2{)}_{1}\ensuremath{\bigotimes}SU(2{)}_{2}\ensuremath{\bigotimes}U(1{)}_{Y}\ensuremath{\rightarrow}SU(2{)}_{L}\ensuremath{\bigotimes}U(1{)}_{Y}$ (breaking pattern II). Examining the single production channel of ${W}^{\ensuremath{'}}$ and ${Z}^{\ensuremath{'}}$ with their subsequent leptonic decays, we find that the probability of detecting ${W}^{\ensuremath{'}}$ and ${Z}^{\ensuremath{'}}$ bosons in the considered models at the LHC (with 14 TeV) is highly limited by the low energy precision data constraints. We show that observing ${Z}^{\ensuremath{'}}$ alone, without seeing a ${W}^{\ensuremath{'}}$, does not rule out new physics models with non-Abelian gauge extension, such as the phobic models in breaking pattern I. Models in breaking pattern II would predict the discovery of degenerate ${W}^{\ensuremath{'}}$ and ${Z}^{\ensuremath{'}}$ bosons at the LHC.