40  0  0.1  0.2  0.3  0.4  0.5  0.6  0.7  0.8  1  1.2  1.4  1.6  1.8 A$^{π}$ 0 0 Br X 10 6 FIG. 13: The correlation plot between the direct CP asymmetry and the CP-averaged branching ratio for the B 0 → π $^{0}$π0 process where the grey region corresponds to the SM result and the red and blue regions correspond to m$_{t}$ ′ =400 and 600 GeV respectively. The horizontal and vertical lines represent the 1- σ experimental range of the corresponding observables. and R 1 = 1 + ( r$_{1}$a$_{1}$ ) 2 + ( r ′ $_{1}$b$_{1}$ ) $^{2}$. Now varying λ d t ′ between 0 and 1 . 5 × 10 − 4 and φ$_{d}$ between (0 − 360) ◦ we present the correlation plot between the direct CP asymmetry parameter and branching ratio in Fig. 13. From the figure one can see that the observed data could be accommodated in the SM with four generations. Standard Model with four generations should be considered seriously. We do not have a good understanding of fermion generations. We have already seen three; why not the fourth? Electroweak precision tests do not rule out the existence of a fourth family, though they do require that the mass difference between the t ′ and the b ′ be less than about 75 GeV. This degeneracy amounting to O(10%) for ≈ 500 GeV masses does not seem so serious. Of course, the electroweak precision tests suggest then a possible heavy Higgs particle but this actually may be hinting at a very interesting resolution to the hierarchy puzzle. This is because heavier quarks of the 4th generation can play a significant role in dynamical electroweak-symmetry breaking, i.e. a composite Higgs particle . Another extremely interesting implication of a 4th family is the gigantic improvement over the three generation case in the context of baryogenesis, as in particular emphasized IV. SUMMARY AND OUTLOOK