[en] We address the question of whether the CP-violating phase in the CKM mixing matrix (δ_CKM) can be the only source of all CP violation. We show that in supersymmetric models with new flavour structure beyond the Yukawa matrices, δ_CKM can generate the required baryon asymmetry and also accounts for all observed results in K and B systems, in particular ε'/ε and the CP asymmetry of B→phiK_S

[en] Non-universality in the soft breaking terms is a common feature in most superstring inspired SUSY models. This property is required to obtain sizeable CP violation effects from SUSY and, on the other hand, can be used to avoid the electric dipole moment (EDM) constraints. We take advantage of these qualities and explore a class of SUSY models based on type I string theory where scalar masses, gaugino masses and trilinear couplings are non-universal. In this framework, we show that, in the presence of large SUSY phases, the bounds on the electric dipole moments can be controlled without fine-tuning. At the same time, we find that these phases, free from EDM constraints, lead to large contributions to the observed CP phenomena in Kaon system and, in particular, to direct CP violation in ε'/ε

[en] For varying values of tanβ, we study the effect of CP-violating phases from the soft supersymmetry breaking terms in string-inspired models on the relic abundance and detection rates of the lightest neutralino (LSP). We find that the phases have no significant effect on the LSP relic abundance but can have a substantial impact on its detection rates

[en] The minimal superstring unification, assuming orbifold compactification, provides interesting and rather detailed implications on physics at low energy. The interesting feature of this model is that the masses of the spectrum are related since all of them are functions of only two parameters: the goldstino angle θ and the gravitino mass m_3/2. This fact will help us in studying the modification of the supersymmetric magnetic moments sum rules which are very sensitive to the supersymmetry breaking. We write these rules in case of exact supersymmetry in a form close to the supersymmetric mass relations, namely Σ_J (-1)^(2J)(2J)A_J=0, where A_J is the anomalous magnetic moment of the spin-J particle. We show that the anomalous magnetic-moments of the W-boson and the gauginos can be written as functions of θ and m_3/2. Then we obtain a modified version of the supersymmetric magnetic-moment sum rule in the context of the minimal superstring unification. (author)

[en] We review the possibility of having a low energy (≤TeV) B-L extension of the Standard Model (SM), which is based on the gauge group SU(3)_C x SU(2)_L x U(1)_Y x U(1)_B-L. This class of models can provide a natural explanation for the presence of three right-handed neutrinos, which are essential for accommodating the light neutrino masses. In addition, the model predicts the existence of an extra gauge boson and a new scalar Higgs. Therefore, it may lead to very interesting phenomenological implications different from the SM results which can be tested at the LHC. A summary of detailed analysis for the neutrino masses and mixing, for the U(1)_B-L Higgs phenomenology, for right-handed neutrino signature, and for Leptogenesis is given. (author)

[en] We study the phenomenological implications of supersymmetric type I string inspired models in which the standard model (SM) gauge groups originate from the same set of D9 branes. We analyse the flavour structure and CP violating phases of soft supersymmetry breaking parameters in this class of model, under the assumption that dilaton and moduli fields contribute to supersymmetry breaking. It turns out that although the soft terms are generically non-universal they have a universal CP violating phase which can be rotated away by using U(1)_R symmetry. Therefore, the only source of the CP violation in these models is the standard model phase in the Cobbibo-Kobayashi-Maskawa (CKM) mixing matrix. The electric dipole moment of the neutron and the mercury atom are predicted to be within one to two orders of magnitude below the present experimental limits. (author)

[en] We study the inclusive branching ratio for B→X_sγ in a class of string-inspired SUSY models with non-universal soft-breaking A-terms. We show that b→sγ do not severely constrain the non-universality of these models and the parameter regions which are important for generating a sizeable contribution to ε'/ε, of the order of 2x10^-3, are not excluded. We also show that the CP asymmetry of this decay is predicted to be much larger than the standard model prediction over a wide region of the parameter space. In particular, it can be of the order of 10-15% which can be accessible at B factories. (author)

[en] We show that the recent results of 5.2σ difference between the CP asymmetries of B⁰→K⁺π^- and B⁺→K⁺π⁰ decays can be accommodated in supersymmetric models with non-universal A-terms.

[en] We review moduli stabilization in type IIB string theory compactification with fluxes. We focus on KKLT and Large Volume Scenario (LVS). We show that the predicted soft SUSY breaking terms in KKLT model are not phenomenological viable. In LVS, the following result for scalar mass, gaugino mass, and trilinear term is obtained: m_0=m_1_/_2=-A_0=m_3_/_2, which may account for Higgs mass limit if m_3_/_2~O(1.5) TeV. However, in this case, the relic abundance of the lightest neutralino cannot be consistent with the measured limits. We also study the cosmological consequences of moduli stabilization in both models. In particular, the associated inflation models such as racetrack inflation and Kähler inflation are analyzed. Finally, the problem of moduli destabilization and the effect of string moduli backreaction on the inflation models are discussed.

[en] We derive new model independent constraints on the supersymmetric extensions of the standard model from the new experimental measurements of B_s-B_s mass difference. We point out that supersymmetry can still give a significant contribution to the CP asymmetry of B_s→J/ψφ that can be measured at the LHCb experiment. These new constraints on the LL and RR squark mixing severely restricted their possible contributions to the CP asymmetries of B→φK and B→η^'K. Therefore, SUSY models with dominant LR flavor mixing is the only way to accommodate the apparent deviation of CP asymmetries from those expected in the standard model. Finally we present an example of SUSY nonminimal flavor model that can accommodate the new ΔM_Bs results and also induces significant CP asymmetries in B_s→J/ψφ, B→φK, and B→η^'K processes