We present simplified MSSM models for light neutralinos and charginos with
realistic mass spectra and realistic gaugino-higgsino mixing, that can be used
in experimental searches at the LHC. The formerly used naive approach of
defining mass spectra and mixing matrix elements manually and independently of
each other does not yield genuine MSSM benchmarks. We suggest the use of less
simplified, but realistic MSSM models, whose mass spectra and mixing matrix
elements are the result of a proper matrix diagonalisation. We propose a novel
strategy targeting the design of such benchmark scenarios, accounting for
user-defined constraints in terms of masses and particle mixing. We apply it to
the higgsino case and implement a scan in the four relevant underlying
parameters {{\mu}, tan\beta, M_1, M_2} for a given set of light neutralino and
chargino masses. We define a measure for the quality of the obtained
benchmarks, that also includes criteria to assess the higgsino content of the
resulting charginos and neutralinos. We finally discuss the distribution of the
resulting models in the MSSM parameter space as well as their implications for
supersymmetric dark matter phenomenology.Comment: 14 pages, 7 figures; version accepted by EPJ