If accessible at CERN LEP II, chargino production is likely to be one of the few available supersymmetric signals for many years. We consider the prospects for the determination of fundamental supersymmetry parameters in such a scenario. The study is complicated by the dependence of observables on a large number of these parameters. We propose a straightforward procedure for disentangling these dependences and demonstrate its effectiveness by presenting a number of case studies at representative points in parameter space. Working in the context of the minimal supersymmetric standard model, we find that chargino production by itself is a fairly sensitive probe of the supersymmetry-breaking sector. For significant regions of parameter space, it is possible to test the gaugino mass unification hypothesis and to measure the gaugino contents of the chargionos and neutralinos, thereby testing the predictions of grand unification and the viability of the lightest supersymmetric particle as a dark matter candidate. For much of the parameter space, it is also possible to set limits on the mass of the electron sneutrino, which provide a valuable guide for future particle searches. © 1995 The American Physical Society.

In this work, we consider the case of a strongly coupled dark/hidden sector, which extends the Standard Model (SM) by adding an additional non-Abelian gauge group. These extensions generally contain matter fields, much like the SM quarks, and gauge fields similar to the SM gluons. We focus on the exploration of such sectors where the dark particles are produced at the LHC through a portal and undergo rapid hadronization within the dark sector before decaying back, at least in part and potentially with sizeable lifetimes, to SM particles, giving a range of possibly spectacular signatures such as emerging or semi-visible jets. Other, non-QCD-like scenarios leading to soft unclustered energy patterns or glueballs are also discussed. After a review of the theory, existing benchmarks and constraints, this work addresses how to build consistent benchmarks from the underlying physical parameters and present new developments for the pythia Hidden Valley module, along with jet substructure studies. Finally, a series of improved search strategies is presented in order to pave the way for a better exploration of the dark showers at the LHC.