In the limit of a pure Higgsino-like chargino and a decoupled wino,these contributions can be approximated by △C+ tan(m+fa(m/m), 1 (14) △C m M3 t.(m M2)-uXtcanm f3(m/M2) (15) mμ2 with X:=A-Her/tan B and loop functions [41,42] i(x)= 7x-5x2-8x3,3x3-2x2 72c-19+12c-血x, 3x-5x2.3z2-2x f2(x)= 12x-1p+6c-1y nz, 7x2-13x3,3x4+2.x3-2x2 f3(x)= 12(e-103+ 6(x-1)4 Inx. (16) 500 300， mi=1 TeV 1.31 mH+300 GeV 280 260 240 125 1.3 1.25 200 180 160 100 100 200 300 400 5s00 400 600 800 100 mH+[GeV] mi [GeV] Figure 6:The ratio R as a function of the chargino mass and the charged Higgs mass (left) and stop mass(right).In both plots X:=0,M2=2 TeV and tan B=1 have been used While the charged Higgs loop depends only on the mass of the Higgs (and the top quark),the chargino loop depends on the stop sector as well as on the wino mass M2 in addition.In order to evade the experimental bound on R either the charged Higgs has to be sufficiently heavy,or there has to be a cancellation between the contributions 9In the limit of a pure Higgsino-like chargino and a decoupled wino, these contributions can be approximated by ∆C H+ 7 ' 1 tan2 β f1(m2 t /m2 H+ ) + f2(m2 t /m2 H+ ) , (14) ∆C χ˜ + 7 ' − m2 t m2 t˜ M2 2 µ 2 eff f1(m2 t˜/M2 2 ) − µXt tan β m2 t m4 t˜ M2 2 µ 2 eff f3(m2 t˜/M2 2 ) , (15) with Xt = At − µeff/ tan β and loop functions [41, 42] f1(x) = 7x − 5x 2 − 8x 3 72(x − 1)3 + 3x 3 − 2x 2 12(x − 1)4 ln x , f2(x) = 3x − 5x 2 12(x − 1)2 + 3x 2 − 2x 6(x − 1)3 ln x , f3(x) = 7x 2 − 13x 3 12(x − 1)3 + 3x 4 + 2x 3 − 2x 2 6(x − 1)4 ln x . (16) 100 200 300 400 500 100 200 300 400 500 1.31 1.25 1.2 1.1 m˜χ + [GeV] mH+ [GeV] mt˜ = 1 TeV 200 400 600 800 1000 160 180 200 220 240 260 280 300 1.31 1.25 1.2 1.1 m˜χ + [GeV] mt˜ [GeV] mH+ = 300 GeV Figure 6: The ratio R as a function of the chargino mass and the charged Higgs mass (left) and stop mass (right). In both plots Xt = 0, M2 = 2 TeV and tan β = 1 have been used. While the charged Higgs loop depends only on the mass of the Higgs (and the top quark), the chargino loop depends on the stop sector as well as on the wino mass M2 in addition. In order to evade the experimental bound on R either the charged Higgs has to be sufficiently heavy, or there has to be a cancellation between the contributions 9