Search for optimal conditions for exploring double-parton scattering in   four-jet production: $k_t$-factorization approach
  In the present paper we discuss how to maximize the double-parton scattering (DPS) contribution in four-jet production by selecting kinematical cuts. Here both single-parton and double-parton scattering effects are calculated in the $k_T$-factorization approach, following our recent developments of relevant methods and tools. Several differential distributions are shown and discussed in the context of future searches for DPS effects, such as rapidity of jets, rapidity distance, and azimuthal correlations between jets. The dependences of the relative DPS amount is studied as function of those observables. The regions with an enhanced DPS contribution are identified. Future experimental explorations could extract more precise values of $\sigma_{eff}$ and its potential dependence on kinematical variables. 
Krzysztof Kutak, Rafal Maciula, Mirko Serino, Antoni Szczurek and   Andreas van Hameren
hep-ph hep-ex