Muon g-2 in an Alternative Quasi-Yukawa Unification with Low Fine-Tuned Inverse SeeSaw Mechanism

Abstract

We explore the low scale implications of the Pati-Salam Model including the TeV scale right-handed neutrinos interacting and mixing with the MSSM fields through the inverse seesaw (IS) mechanism in the light of the muon anomalous magnetic moment (muon g-2) resolution, and highlight the solutions which are compatible with the Quasi-Yukawa Unification condition (QYU). We find that the presence of the right-handed neutrinos causes heavy smuons >~ 800 GeV in order to avoid tachyonic staus at the low scale. On the other hand, the sneutrinos can be as light as about 100 GeV along with the light charginos of mass <~ 400 GeV, they can yield so large contributions to muon g-2 that the discrepancy between the experiment and the theory can be resolved. In addition, the model predicts relatively light Higgsinos (<~ 700 GeV); and hence the second chargino mass is also light enough (<~ 700 GeV) to contribute to muon g-2. Light Higgsinos also yield less fine-tuning at the electroweak scale, and the regions compatible with muon g-2 restricts Delta_EW <~ 100 strictly, and this region also satisfies the QYU condition. In addition, the ratios among the Yukawa couplings should be 1.8 <~ y_t/y_b <~ 2.6, y_tau/y_b ~ 1.3 to yield correct fermion masses. Even though the right-handed neutrino Yukawa coupling can be varied freely, the solutions bound its range to 0.8 <~ y_nu/y_b <~ 1.7.