Signatures of extra gauge bosons in the littlest Higgs model with<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>T</mml:mi></mml:math>parity at future colliders

Abstract

We study the collider signatures of a $T$-odd gauge boson ${W}_{H}$ pair production in the littlest Higgs model with $T$ parity (LHT) at Large Hadron Collider (LHC) and Linear Collider (LC). At the LHC, we search for the ${W}_{H}$ boson using its leptonic decay, i.e. $pp\ensuremath{\rightarrow}{W}_{H}^{+}{W}_{H}^{\ensuremath{-}}\ensuremath{\rightarrow}{A}_{H}{A}_{H}{\ensuremath{\ell}}^{+}{\ensuremath{\nu}}_{\ensuremath{\ell}}{\ensuremath{\ell}}^{\ensuremath{'}\ensuremath{-}}{\overline{\ensuremath{\nu}}}_{{\ensuremath{\ell}}^{\ensuremath{'}}}$, which gives rise to a collider signature of ${\ensuremath{\ell}}^{+}{\ensuremath{\ell}}^{\ensuremath{'}\ensuremath{-}}+{\mathrm{E\ensuremath{\llap{\not\;}}}}_{T}$. We demonstrate that the LHC not only has a great potential of discovering the ${W}_{H}$ boson in this channel, but also can probe enormous parameter space of the LHT. Because of four missing particles in the final state, one cannot reconstruct the mass of ${W}_{H}$ at the LHC. But such a mass measurement can be easily achieved at the LC in the process of ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{W}_{H}^{+}{W}_{H}^{\ensuremath{-}}\ensuremath{\rightarrow}{A}_{H}{A}_{H}{W}^{+}{W}^{\ensuremath{-}}\ensuremath{\rightarrow}{A}_{H}{A}_{H}jjjj$. We present an algorithm of measuring the mass and spin of the ${W}_{H}$ boson at the LC. Furthermore, we illustrate that the spin correlation between the $W$ boson and its mother particle (${W}_{H}$) can be used to distinguish the LHT from other new physics models.