The specificity of searches for $W^{\prime }$, $Z^{\prime }$ and ${\gamma }^{\prime }$ coming from extra dimensions

Abstract

We discuss the specificity of searches for hypothetical $W^{\prime }$, $Z^{\prime }$ and ${\gamma }^{\prime }$ bosons at hadron colliders in single top quark and ${\mu }^{+}{\nu }_{\mu }$ production and Drell-Yan processes assuming these particles to be the Kaluza-Klein excitations of the gauge bosons of the Standard Model. In this case any process mediated by $W$ is also mediated by the whole KK tower of its excitations, whereas to the processes mediated by $Z$ and $\gamma$ there is not only a contribution from their KK towers, but also from that of the graviton. The contributions of the towers above $W^{\prime }$, $Z^{\prime }$ and ${\gamma }^{\prime }$ and above the first excitation of the graviton are included with the help of effective four-fermion Lagrangians. We compute the cross-sections of these processes taking into account the contributions of the Standard Model gauge bosons, of their first KK modes and of the corresponding KK towers and discuss the impact of the interference between them. For pp-collisions at the LHC with the center of mass energy 14 TeV we found specific changes of the distribution tails due to the interference effects. Such a modification of distribution tails is characteristic for the processes mediated by particles coming from extra dimensions and should always be taken into account when looking for them.

Comments: 14 pages, 12 figures, LaTeX. References added, figures added, text enlarged