Supersymmetric model contributions to B-d(0)-(B)over-bar(d)(0) mixing and B -> pi pi, rho gamma decays

Recent results from the Belle and BaBar Collaborations hint at a small sin2 phi1, while the measured B --> pi pi rate also seems to be on the low side . Supersymmetric (SUSY) models with down squark mixings can account for the deficits in both cases. By studying the origin of SUSY contributions that could impact on B-d(0)-(B) over bar (0)(d) mixing and B --> pi pi decay, we find that the former would most likely arise from loft-left or right-rig s quark mixings, while the latter would come from left-right squark mixings. These two processes in general are not much correlated in the minimum super symmetric standard model. If the smallness of B --> pi pi is due to SUSY mo dels, one would likely have a large B --> rho gamma from chiral enhancement , and the rate could be within the present experimental reach. Even if B -- > rho gamma is not greatly enhanced, it could have large mixing dependent C P violation.