Building Natural Grand Unified Model, the Predictions, and Derivation from Superstring Theory

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Since I found in 2001 that the doublet-triplet splitting problem, the most serious problem in the supersymmetric grand unified theory (SUSY GUT), can be solved under a natural assumption that all the terms allowed by the symmetry are introduced with O(1) coefficients, we have reconsidered the various problems in the standard model or in SUSY GUT We have found that various problems can be solved in the same natural assumptions in non-trivial way. Then we have obtained a natural, simple and promising scenario as beyond the standard model. This scenario consists of 3 independent ideas. "Anomalous U(1) GUT", "E6 unified group and horizontal symmetry", and "Light Higgs sector".The results supported by this fund are on the second half of the 3 ideas above. One of them is that we give some predictions from the peculiar sfermion mass spectrum obtained from E6 unified group and horizontal symmetry. We showed that under some reasonable assumptions, the discrepancy from the standard model predictions can be found in near future in lepton flavor violation experiments and we calculated the quantitative predictions. We are now studying the predictions for CP violation in B decay in this scenario. One of the interesting results is that we found the third idea in the above and by detailed calculations we confirmed the possibility can be realistic. In SUSY theories, the little hierarchy problem is known that a finetuning is required to obtain the larger Higgs mass than the lower bound obtained by LEP experiments. We proposed an interesting solution for the problem and discussed the predictions.We only list the published papers below. We obtained various results which have not been published yet. We have plans to publish these interesting works in near future.