Trileptons from chargino-neutralino production at the CERN Large Hadron Collider

We study direct production of charginos and neutralinos at the CERN Large Hadron Collider. We simulate all channels of chargino and neutralino production using isajet 7.07. The best mode for observing such processes appears to be pp{→}W̃ \~₁Z̃ \~₂{→}3l+E/T. We evaluate signal expectations and background levels, and suggest cuts to optimize the signal. The trilepton mode should be viable provided mg ̃ \~{}{}{}500--600 GeV; above this mass, the decay modes Z̃ \~₂{→}Z̃ \~₁Z and Z̃ \~₂{→}HₗZ̃ \~₁ become dominant, spoiling the signal. In the first case, the leptonic branching fraction for Z decay is small and additional background from WZ is present, while in the second case, the trilepton signal is essentially absent. For smaller values of mg ̃ \~{}{}, the trilepton signal should be visible above background, especially if {}{μ}{}{}mg ̃ \~{}{} and mₗ ̃ \~{}{}{}mq ̃ \~{}{}, in which case the leptonic decays of Z̃ \~₂ are enhanced. Distributions in dilepton mass m(ll{}) can yield direct information on neutralino masses due to the distribution cutoff at m_Z ̃ \~2-m_Z ̃ \~1. Other distributions that may lead to an additional constraint amongst the chargino and neutralino masses are also examined.