As originally demonstrated in [ 5,6 ] , the values of the relevant SM parameters can strongly influence some of the CMSSM predictions , and , in contrast to common practice , should not be simply kept fixed at their central values . We thus introduce a set ψ of so - called " nuisance parameters " of the SM parameters which are relevant to our analysis , The set of parameters θ and ψ form an 8 - dimensional set m of our " basis parameters " ( 2.1 ) . In terms of the basis parameters we compute a number of collider and cosmological observables , which we call " derived variables " and which we collectively denote by the set ξ = ( ξ 1 , ξ 2 , . . . ) . The observables will be used to compare CMSSM predictions with a set of experimental data d , which is available either in the form of positive measurements or as limits , as discussed below . Table 1 : Experimental mean µ and standard deviation σ adopted for the likelihood function for SM ( nuisance ) parameters , assumed to be described by a Gaussian distribution .