Flipped $$\mathbf {g_\mu - 2}$$

We analyze the possible magnitude of the supersymmetric contribution to $$g_\mu - 2$$ g μ - 2 in a flipped SU(5) GUT model. Unlike other GUT models which are severely constrained by universality relations, in flipped SU(5) the U(1) gaugino mass and the soft supersymmetry-breaking masses of right-handed sleptons are unrelated to the other gaugino, slepton and squark masses. Consequently, the lightest neutralino and the right-handed smuon may be light enough to mitigate the discrepancy between the experimental measurement of $$g_\mu - 2$$ g μ - 2 and the Standard Model calculation, in which case they may be detectable at the LHC and/or a 250 GeV $$e^+ e^-$$ e + e - collider, whereas the other gauginos and sfermions are heavy enough to escape detection at the LHC.

A minimal supersymmetric SU(5) missing-partner model

We explore a missing-partner model based on the minimal SU(5) gauge group with $$\mathbf{75} $$ 75 , $$\mathbf{50} $$ 50 and $$\overline{\mathbf{50 }}$$ 50 ¯ Higgs representations, assuming a super-GUT CMSSM scenario in which soft supersymmetry-breaking parameters are universal at some high scale $$M_{\mathrm{in}}$$ M in above the GUT scale $$M_{\mathrm{GUT}}$$ M GUT . We identify regions of parameter space that are consistent with the cosmological dark matter density, the measured Higgs mass and the experimental lower limit on $$\tau (p \rightarrow K^+ \nu )$$ τ ( p → K + ν ) . These constraints can be satisfied simultaneously along stop coannihilation strips in the super-GUT CMSSM with $$\tan \beta \sim $$ tan β ∼ 3.5–5 where the input gaugino mass $$m_{1/2} \sim $$ m 1 / 2 ∼ 15–25 TeV, corresponding after strong renormalization by the large GUT Higgs representations between $$M_{\mathrm{in}}$$ M in and $$M_{\mathrm{GUT}}$$ M GUT to $$m_{\mathrm{LSP}}, m_{{\tilde{t}}_1} \sim $$ m LSP , m t ~ 1 ∼ 2.5–5 TeV and $$m_{{\tilde{g}}} \sim $$ m g ~ ∼ 13–20 TeV, with the light-flavor squarks significantly heavier. We find that $$\tau (p \rightarrow K^+ \nu ) \lesssim 3 \times 10^{34}$$ τ ( p → K + ν ) ≲ 3 × 10 34 years throughout the allowed range of parameter space, within the range of the next generation of searches with the JUNO, DUNE and Hyper-Kamiokande experiments.

SU(5) with nonuniversal gaugino masses

We explore the sparticle spectroscopy of the supersymmetric SU(5) model with nonuniversal gaugino masses in light of latest experimental searches. We assume that the gaugino mass parameters are independent at the GUT scale. We find that the observed deviation in the anomalous magnetic moment of the muon can be explained in this model. The parameter space that explains this deviation predicts a heavy colored sparticle spectrum whereas the sleptons can be light. We also find a notable region of the parameter space that yields the desired relic abundance for dark matter. In addition, we analyze the model in light of latest limits from direct detection experiments and find that the parameter space corresponding to the observed deviation in the muon anomalous magnetic moment can be probed at some of the future direct detection experiments.

Aspects of Moduli Stabilization in Type IIB String Theory

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:m0=m1/2=-A0=m3/2, which may account for Higgs mass limit ifm3/2~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.