38 hard spectator contribution $^{5}$. Since λ$_{B}$ and Λ$_{QCD}$ were previously fixed to 200 MeV and 225 MeV respectively to fit the data interpreted in SM3, it may not be unreasonable to assume small changes for SM4. For the CKM matrix elements we use values as given in the Table I. We have also used the range of λ$_{t}$ ′ and φ$_{s}$ as obtained from the fit for different m$_{t}$ ′ . Using these values we show the allowed regions in the Δ A$_{CP}$ − λ$_{t}$ ′ plane for different values of m$_{t}$ ′ in figure 11 and we note that an enhancement in Δ A$_{CP}$ upto the current 1 σ experimental upper bound ( ≈ 17 . 6%) is possible for largish strong phases, φ$_{A,H}$ ∼ ( − 45 → − 90) ◦ . The correlation plots between mixing induced and direct CP asymmetry parameters in B 0 → π $^{0}$K0 modes are shown in figure 12. As discussed earlier there exists several hints for the possible existence of new physics in the b → s sector. So the next obvious question is: Do the b → d penguin amplitudes also have significant new physics contribution? The present data does not provide any conclusive answer to it. The obvious example is the B → ππ processes, which receive dominant contribution from b → u tree and from b → d penguin diagrams. The present data [52] are presented in Table VII. Thus, it can be seen that the measured value of Br( B 0 → π $^{0}$π$^{0}$) is nearly two times larger than the corresponding theoretical predictions Decay mode HFAG Average 10 6 × Br( B 0 → π $^{+}$π − ) 5 . 16 ± 0 . 22 10 6 × Br( B − → π − π $^{0}$) 5 . 59 ± 0 . 41 10 6 × Br( B 0 → π $^{0}$π$^{0}$) 1 . 55 ± 0 . 19 S$_{π}$ $^{+}$π − − 0 . 65 ± 0 . 07 A$_{π}$ $^{+}$π − 0 . 38 ± 0 . 06 A$_{π}$ − π 0 0 . 06 ± 0 . 05 A$_{π}$ $^{0}$π0 0 . 43 +0 . 25 − 0 24 TABLE VII: Experimental results for B → ππ processes 5 The corresponding choices in the scenario S4 of [38] are given by F B → K 0 (0) = 0 . 31, F B → π 0 (0) = 0 . 25, f$_{π}$ = 0 . 131 GeV, f$_{K}$ = 0 . 16 GeV, λ$_{B}$ = 200 MeV, φ$_{A,H}$ = − 55 ◦ and Λ$_{QCD}$ = 225 MeV K. CP violation in B 0 → π $^{0}$π0 modes